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As filed with the Securities and Exchange Commission on September 26, 2016

Registration No. 333-            


UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549



FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933



LEAP THERAPEUTICS, INC.
(Exact Name of Registrant as Specified in Its Charter)

Delaware
(State of Incorporation)
  2834
(Primary Standard Industrial
Classification Code Number)
  27-4412575
(IRS Employer
Identification No.)

47 Thorndike Street
Suite B1-1
Cambridge, MA 02141
Telephone: (617) 714-0360



Christopher K. Mirabelli, Ph.D.
Chairman, President and Chief Executive Officer
Leap Therapeutics, Inc.
47 Thorndike Street, Suite B1-1
Cambridge, MA 02141
(617) 714-0360

(Name, Address, including Zip Code, and Telephone Number, including Area Code, of Agent for Service)



With copies to:

Julio E. Vega, Esq.
William S. Perkins, Esq.
Morgan, Lewis & Bockius LLP
One Federal Street
Boston, MA 02110-1726
(617) 951-8901

 

David J. Friedman, Esq.
Phyllis G. Korff, Esq.
Skadden, Arps, Slate, Meagher & Flom LLP
Four Times Square
New York, New York 10036
(212) 735-3000

 

Ronen Bezalel, Esq.
David S. Glatt, Esq.
Jonathan M. Nathan, Esq.
Meitar Liquornik Geva Leshem Tal
16 Abba Hillel Silver Road, Ramat
Gan, 5250608, Israel
972-3-610-3100



Approximate date of commencement of proposed sale of the securities to the public:
As soon as practicable after this registration statement is declared effective and all other conditions to the transactions described in this registration statement have been satisfied or waived.

           If the securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, please check the following box.     o

           If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the "Securities Act"), check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.     o

           If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.     o

           Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer  o   Accelerated filer  o   Non-accelerated filer  ý
(Do not check if a
smaller reporting company)
  Smaller reporting company  o

CALCULATION OF REGISTRATION FEE

               
 
Title of each class of securities
to be registered

  Amount to be
registered

  Proposed maximum
offering price per
unit

  Proposed maximum
aggregate offering
price

  Amount of
registration fee

 

Common stock, par value $0.001 per share

  3,605,235(1)   N/A   $29,135,214.13(2)   $2,933.92(3)

 

(1)
Represents the maximum number of shares of common stock, par value $0.001 per share, of the Registrant estimated to be issuable upon completion of the proposed merger of M-CO Merger Sub Ltd., a wholly owned subsidiary of the Registrant, with and into Macrocure Ltd. as set forth in the merger agreement described herein.

(2)
Pursuant to Rules 457(c) and 457(f)(1) of the Securities Act and estimated solely for the purpose of calculating the registration fee, the proposed aggregate maximum offering price is $29,135,214.13. Such amount equals the product of (a) 3,605,235, the estimated maximum number of shares to be registered, and (b) the quotient obtained by dividing (i) $1.47, the average of the high and low sales prices of Macrocure ordinary shares, par value NIS 0.01 per share, as reported on the NASDAQ Global Market on September 20, 2016, and (ii) the estimated exchange ratio of 0.1819. There is currently no market for Leap's securities.

(3)
Estimated in accordance with Rule 457(f) under the Securities Act, which is based on 0.0001007 multiplied by the proposed maximum aggregate offering price of $29,135,214.13.



            The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

   


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The information in this prospectus is not complete and may be changed. Leap Therapeutics, Inc. may not sell the securities offered by this prospectus until the registration statement filed with the U.S. Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and Leap Therapeutics, Inc. is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY—SUBJECT TO COMPLETION, DATED SEPTEMBER 26, 2016



LOGO

SHARES OF COMMON STOCK,
PAR VALUE $0.001 PER SHARE
TO BE ISSUED IN CONNECTION WITH THE PROPOSED MERGER OF MACROCURE LTD. WITH M-CO MERGER SUB LTD., A WHOLLY OWNED SUBSIDIARY OF LEAP THERAPEUTICS, INC.

THIS IS NOT A PROXY STATEMENT. WE ARE NOT ASKING YOU FOR A PROXY AND YOU ARE REQUESTED NOT TO SEND US A PROXY.



        This prospectus of Leap Therapeutics, Inc., a Delaware corporation ("Leap", "us" or "we"), relates to shares of Leap common stock, par value $0.001 per share ("Leap common stock"), to be issued to the holders of ordinary shares, par value NIS 0.01 per share ("Macrocure ordinary shares"), of Macrocure Ltd., a company formed under the laws of the State of Israel ("Macrocure"), as provided for by an Agreement and Plan of Merger, dated August 29, 2016, by and among Leap, Macrocure and M-CO Merger Sub Ltd., a company formed under the laws of the State of Israel and a wholly owned subsidiary of Leap ("Merger Sub"). A copy of the merger agreement is attached as Annex A to this prospectus.

        Pursuant to the terms and subject to the conditions of the merger agreement, at the effective time of the merger contemplated by the merger agreement, (i) Merger Sub (as the target company, or Chevrat Ha'Ya'ad ) will be merged with and into Macrocure (as the absorbing company, or HaChevra Ha'Koletet ) with Macrocure as the surviving corporation in the merger and thereby becoming a wholly owned subsidiary of Leap and (ii) each Macrocure ordinary share issued and outstanding immediately prior to the effective time of the merger) shall be converted into the right to receive that number of fully paid and nonassessable shares of Leap common stock and cash in lieu of fractional shares as specified in the merger agreement. Upon consummation of the merger, the holders of Macrocure ordinary shares (and any instrument exercisable for Macrocure ordinary shares) will become holders of shares of Leap common stock (or instruments exercisable for shares of Leap common stock, as applicable). A copy of Macrocure's proxy statement, which will be submitted by Macrocure to the U.S. Securities and Exchange Commission (the "Commission") as an exhibit to a Report of Foreign Private Issuer on Form 6-K, will be mailed to the holders of Macrocure ordinary shares.

        The merger agreement requires that the Israeli Registrar of Companies approve the merger and issue a certificate evidencing the merger in accordance with Section 323(5) of the Israeli Companies Law (the "Companies Law") and that the holders of Macrocure ordinary shares approve the merger and related matters at a shareholder meeting. The meeting of the holders of Macrocure ordinary shares will be held on                    , 2016, at        :         a.m., at                    , which meeting and any adjournments or postponements thereof is referred to as the "Macrocure Shareholder Meeting". At the Macrocure Shareholder Meeting, holders of Macrocure ordinary shares of record as of the record date to be determined by Macrocure will be asked to consider and approve the merger.

        Leap is an "emerging growth company" under the Jumpstart Our Business Startups Act of 2012 and applicable rules of the Commission, and therefore is eligible to rely on reduced public company reporting requirements.

        THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

   

The date of this prospectus is                    , 2016


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ADDITIONAL INFORMATION

        Macrocure is subject to the information requirements of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), applicable to "foreign private issuers", and, in accordance therewith, files and submits reports and other information with the Commission. The reports and other information filed by Macrocure with the Commission are available through the Commission's website at http://www.sec.gov and can also be inspected and copied at the public reference facilities maintained by the Commission at Room 1024, 100 F Street, NE, Washington, DC 20549, at prescribed rates. Macrocure ordinary shares are listed on the NASDAQ Global Market under the symbol "MCUR".

        Leap has filed with the Commission a registration statement on Form S-4 (the "Registration Statement") under the Securities Act of 1933, as amended (the "Securities Act"), of which this prospectus is a part. This prospectus does not contain all of the information set forth in the Registration Statement, certain parts of which have been omitted in accordance with the rules and regulations of the Commission. Statements contained in this prospectus concerning the provisions of any contract or other document are necessarily summaries of such documents, and, where such document has been filed with the Commission as an exhibit to the Registration Statement, each statement contained herein concerning such document is qualified in its entirety by reference to the copy of the applicable document filed with the Commission. Where a description of such a document is included in this prospectus, such description summarizes the material terms of such document. Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

        As a result of registering the securities offered hereby, Leap will become subject to the information and reporting requirements of the Exchange Act and, in accordance therewith, will file reports and other information with the Commission. Reports and other information that will be filed by Leap will be available for inspection and copying as set forth above with respect to reports and other information related to Macrocure. These reports and other information will also be available at a website maintained by the Commission that contains reports, proxy and information statements and other information that registrants file electronically with the Commission. The address of the Commission's website is: http://www.sec.gov .


ABOUT THIS PROSPECTUS

        This document, which forms part of a Registration Statement on Form S-4 filed with the Commission by Leap (File No. 333-                    ), constitutes a prospectus of Leap under Section 5 of the Securities Act with respect to the shares of Leap common stock to be issued pursuant to the merger agreement.

        All information concerning Leap contained in this prospectus has been furnished by Leap; all information concerning Merger Sub contained in this prospectus has been furnished by Leap; and all information concerning Macrocure prior to the consummation of the merger contained in this prospectus has been furnished by Macrocure. Macrocure does not have independent knowledge of the matters set forth herein regarding Leap, Merger Sub or Leap's other subsidiaries, and Leap does not have independent knowledge of the matters set forth herein regarding Macrocure or its subsidiaries.

        You should rely only on the information contained in this prospectus. Leap and Macrocure have not authorized anyone to provide you with information or to make any representation with respect to the matters described in this prospectus other than those contained herein and, if given or made, such information or presentation must not be relied upon as having been authorized by Leap, Merger Sub, Macrocure or any other person. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities in any jurisdiction in which, or to any person to whom, it is not lawful to make any such offer or solicitation.

        This prospectus is dated                    , 2016, and you should not assume that the information contained in this prospectus is accurate as of any date other than such date. Neither the delivery of this prospectus nor the issuance by Leap of shares of Leap common stock registered hereunder shall, under any circumstances, create any implication that there has been no change in the assets, properties or affairs of Leap, Merger Sub or Macrocure since such date or that the information contained herein is correct as of any time subsequent to such date.

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETING

   
1
 

SUMMARY

   
9
 

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

   
22
 

RISK FACTORS

   
24
 

Risks Relating to the Proposed Merger

    24  

Risks Relating to the Business of Leap and Ownership of Leap common stock following the Merger

    27  

Risks Related to Leap's Financial Position and Capital Needs

    27  

Risks Related to Our Business and Industry

    29  

Risks Related to the Commercialization of Our Product Candidates

    36  

Risks Related to Our Dependence on Third Parties

    43  

Risks Related to Legal and Compliance Matters

    47  

Risks Related to Our Intellectual Property

    49  

INFORMATION ABOUT THE MACROCURE SHAREHOLDER MEETING

   
57
 

The Macrocure Shareholder Meeting

    57  

Voting at the Macrocure Shareholder Meeting

    57  

Solicitation of Proxies

    58  

THE MERGER

   
59
 

The Parties

    59  

General Information Concerning the Merger and Related Agreements

    60  

Background of the Merger

    60  

Recommendation of the Macrocure Board

    64  

Macrocure's Reasons for the Merger

    64  

Leap's Reasons for the Merger

    68  

Related Transactions and Agreements

    70  

Equity Investment

    70  

Voting Agreement

    71  

Royalty Agreement

    71  

Registration Rights Agreement

    72  

Merger Consideration

    72  

Pre-Closing Leap Share Conversion and Recapitalization

    73  

Opinion of Macrocure's Financial Advisor

    73  

Approval of the New Leap Charter and Issuance of Leap Common Stock

    83  

Ownership of Leap following the Merger

    83  

Governance of Leap following the Merger

    83  

Dividend Policy following the Merger

    84  

Amendment and Restatement of Leap Charter and Bylaws

    84  

Closing and Effective Time of the Merger

    84  

Regulatory Approvals

    85  

Federal Securities Law Consequences

    86  

Accounting Treatment

    86  

NASDAQ Stock Market Listing

    86  

Transfer Agent and Registrar

    86  

Delisting and Deregistration of Macrocure Ordinary Shares

    86  

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THE MERGER AGREEMENT

    87  

Explanatory Note Regarding the Merger Agreement

    87  

Terms of the Merger

    87  

Completion and Effectiveness of the Merger

    87  

Allocation of the Merger Consideration Among Macrocure Equityholders

    88  

Merger Consideration and Adjustment

    89  

Determination of Macrocure's Net Cash

    90  

Exchange of Shares in the Merger

    91  

Fractional Shares

    92  

Representations and Warranties

    92  

Conduct of Business

    94  

No Solicitation of Takeover Proposals

    97  

Efforts to Complete the Merger

    98  

Disclosure Documents

    99  

Merger Proposal

    100  

Meeting of Macrocure's and Merger Sub's Shareholders

    100  

Regulatory Approvals

    101  

Macrocure Share Incentive Plans, Stock Options and Warrants

    101  

Leap Stock Options

    101  

Israeli Tax Rulings

    102  

NASDAQ Listing

    102  

Directors

    103  

Other Covenants and Agreements

    103  

Conditions to Consummation of the Merger

    104  

Termination of the Merger Agreement

    105  

Fees and Expenses

    106  

Amendments, Extensions and Waivers

    107  

No Third Party Beneficiaries

    107  

Specific Performance

    108  

Compliance with Deadlines

    108  

SELECTED HISTORICAL FINANCIAL DATA OF LEAP

   
109
 

SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA FOR MACROCURE

   
111
 

SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA

   
113
 

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET

   
117
 

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF OPERATIONS

   
118
 

COMPARATIVE HISTORICAL AND UNAUDITED PRO FORMA PER SHARE DATA

   
114
 

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

   
115
 

NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

   
120
 

COMPARATIVE MARKET PRICE INFORMATION

   
125
 

BUSINESS OF LEAP

   
126
 

General

    126  

Overview

    126  

Our Approach

    128  

Our Products

    130  

Competition

    139  

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Manufacturing

    140  

Government Regulation and Product Approvals

    141  

Properties

    155  

Employees

    155  

Legal Proceedings

    155  

Management's Discussion and Analysis of the Financial Condition and Results of Operations—Leap

    156  

Overview

    156  

Financial Overview

    158  

Results of Operations

    162  

Liquidity and Capital Resources

    165  

Contractual Obligations and Commitments

    167  

Off-Balance Sheet Arrangements

    167  

Recently Issued Accounting Pronouncements

    167  

Qualitative and Quantitative Disclosures about Market Risk

    167  

MANAGEMENT OF LEAP FOLLOWING THE MERGER

    169  

Name of Company

    169  

Executive Officers and Directors of Leap

    169  

Board Composition

    173  

Board Committees

    173  

Code of Conduct for Employees, Executive Officers and Directors

    176  

Compensation Committee Interlocks and Insider Participation

    176  

EXECUTIVE AND DIRECTOR COMPENSATION

    177  

Summary Compensation Table

    177  

Executive Compensation

    177  

Employment Agreements

    178  

Outstanding Equity Awards at Fiscal Year End

    180  

Equity Benefit Plans

    180  

401(k) Plan

    189  

Director Compensation

    189  

CERTAIN BENEFICIAL OWNERS OF LEAP COMMON STOCK

    191  

CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONS OF LEAP

    194  

INFORMATION ABOUT MACROCURE

   
198
 

Macrocure Operating Results

       

History and Development of Macrocure

    198  

Business Overview

    198  

Organizational Structure

    204  

Property, Plants and Equipment

    205  

Exchange Controls

    205  

Operating and Financial Review and Prospects

    205  

Overview

    205  

Financial Operations Overview

    206  

Effective Corporate Tax Rate

    212  

Israeli Tax Structure and Tax Programs That May Become Applicable to Macrocure

    212  

Liquidity and Capital Resources

    213  

Application of Critical Accounting Policies and Estimates

    217  

Recent Accounting Pronouncements

    219  

Jobs Act Exemptions

    219  

Quantitative and Qualitative Disclosures About Market Risk

    220  

Beneficial Owners

    221  

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FINANCIAL INTERESTS OF MACROCURE'S DIRECTORS AND EXECUTIVE OFFICERS IN THE MERGER

    224  

U.S. FEDERAL INCOME TAX CONSIDERATIONS

   
226
 

MATERIAL FOREIGN TAX CONSEQUENCES

   
231
 

NO APPRAISAL RIGHTS

   
234
 

LEGAL INFORMATION

       

Description of Leap Capital Stock

    235  

Shares Eligible for Future Sale

    241  

Comparison of Rights of Holders of Leap Shares and Holders of Macrocure Shares

    243  

Legal Matters

    260  

Experts

    260  

ADDITIONAL INFORMATION FOR SHAREHOLDERS

       

Where You Can Find More Information

    260  

PRESENTATION OF FINANCIAL INFORMATION

       

Index to Financial Statements

    F-1  

INFORMATION NOT REQUIRED IN PROSPECTUS

   
II-1
 

Indemnification of Directors and Officers

   
II-1
 

Exhibit Index

    II-2  

Undertakings

    II-4  

ANNEX A:    Merger Agreement

       

ANNEX B:    Opinion of Raymond James

       

ANNEX C:    New Leap Charter

       

ANNEX D:    New Leap Bylaws

       

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETING

         The following questions and answers are intended to briefly address some commonly asked questions regarding the merger, the merger agreement, the shares of Leap common stock to be issued pursuant to the merger and the Macrocure Shareholder Meeting. These questions and answers may not address all questions that may be important to you as a Macrocure shareholder. Please refer to the section entitled "Summary" beginning on page 9 of this prospectus and the more detailed information contained elsewhere in this prospectus, the annexes to this prospectus and the documents referred to in this prospectus, which you should read carefully and in their entirety.

        Macrocure has agreed to combine with Leap, subject to approval of the Macrocure shareholders, under the terms of the merger agreement that are described in this prospectus. Macrocure is holding a special meeting of its shareholders, which we generally refer to as the "Macrocure Shareholder Meeting," to ask its shareholders to consider and vote upon a proposal to approve the merger agreement and the transactions contemplated thereby, which we generally refer to as the merger proposal, as well as a number of related matters.

        If the merger proposal is approved at the Macrocure Shareholder Meeting and the other conditions to consummation of the merger are satisfied or waived, then at the consummation of the merger, Merger Sub will be merged with and into Macrocure, with Macrocure surviving the merger and becoming a wholly owned subsidiary of Leap. As a result of the merger, Macrocure shareholders will receive shares of Leap common stock for their Macrocure ordinary shares. Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

        This prospectus includes important information about the merger, the merger agreement, a copy of which is attached as Annex A to this prospectus, the shares of Leap common stock to be issued pursuant to the merger and the Macrocure Shareholder Meeting. Macrocure shareholders should read this information carefully and in its entirety.

        Leap is a biopharmaceutical company acquiring and developing novel therapeutics at the leading edge of cancer biology. Our approach is designed to target compelling tumor-promoting and immuno-oncology pathways to generate durable clinical benefit and enhanced outcomes for patients. Our programs are monoclonal antibodies that target key cellular pathways that enable cancer to grow and spread and specific mechanisms that activate the body's immune system to identify and attack cancer. Our two clinical stage programs are:

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        We intend to apply our extensive experience identifying and developing transformational products to aggressively develop these antibodies and build a pipeline of programs that has the potential to change the practice of cancer medicine.

        Yes. The approval of the merger proposal requires the affirmative vote of the holders of a majority of the Macrocure ordinary shares present and entitled to vote on the matter at the Macrocure Shareholder Meeting, excluding abstentions and broker non-votes (and other invalid votes) and excluding any Macrocure ordinary shares that are held by Leap, Merger Sub or by any person holding at least 25% of the means of control of either of them, or anyone acting on behalf of either of them, including any of their affiliates. All holders of record of Macrocure ordinary shares as of the close of business on                        , 2016, the record date for the Macrocure Shareholder Meeting, will be entitled to vote at the special meeting. Each holder of Macrocure ordinary shares will be entitled to cast one vote on each matter properly brought before the Macrocure Shareholder Meeting for each Macrocure ordinary share that such holder owned of record as of the record date. Concurrently with the execution of the merger agreement, certain of Macrocure's shareholders representing more than 50% of the then outstanding ordinary shares of Macrocure (on a fully diluted basis) entered into voting agreements, pursuant to which each such shareholder agreed to vote in favor of the merger proposal at the Macrocure Shareholder Meeting.

        Concurrently with the execution of the merger agreement, Leap obtained all approvals and consents of the holders of its capital stock necessary to effect the merger and the other transactions contemplated by the merger agreement, including approval of the issuance of Leap common stock as merger consideration to the Macrocure shareholders. No further approvals by the holders of Leap capital stock are required to consummate the merger or the other transactions contemplated by the merger agreement other than those already obtained. However, if additional approvals should be required for any reason, the Leap shareholders, in their respective voting agreements, have agreed to take such action.

        Yes. The board of directors of both Leap and Macrocure have approved of the merger and recommended that the stockholders of each of Leap and Macrocure, respectively, vote in favor of the merger proposal. As noted above, Leap has already obtained all approvals and consents of the holders of its capital stock necessary to effect the merger and the other transactions contemplated by the merger agreement. See the section entitled "The Merger Agreement—Recommendation of the Macrocure Board" beginning on page 64 of this prospectus.

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        Yes. Macrocure's financial advisor Raymond James & Associates, Inc. ("Raymond James") has provided an opinion to Macrocure that the consideration to be received by Macrocure shareholders in the merger is fair from a financial point of view. The opinion is attached as Annex B to this prospectus. See the section entitled "The Merger—Opinion of Macrocure's Financial Advisor" beginning on page 73 of this prospectus.

        In addition to approval of the merger proposal by Macrocure shareholders as described above, completion of the merger is subject to the satisfaction of a number of other conditions, including authorization for listing of Leap common stock on the NASDAQ stock market, the effectiveness of the Registration Statement of which this prospectus forms a part, the accuracy of representations and warranties under the merger agreement (subject to certain materiality exceptions), the absence of a material adverse effect on Leap or Macrocure, and Leap's and Macrocure's performance of their respective obligations under the merger agreement. For a more complete summary of the conditions that must be satisfied or waived prior to consummation of the merger, see the section entitled "The Merger Agreement—Conditions to Consummation of the Merger" beginning on page 104 of this prospectus.

        Subject to the satisfaction or waiver of the closing conditions described under the section entitled, "The Merger Agreement—Conditions to Consummation of the Merger" beginning on page 104 of this prospectus, including the approval of the merger proposal by Macrocure shareholders at the Macrocure Shareholder Meeting, Leap and Macrocure expect that the merger will be consummated in late 2016 or early 2017. However, it is possible that factors outside the control of both companies could result in the merger being consummated at a different time or not at all.

        If the merger proposal is not approved by Macrocure shareholders, or if the merger is not consummated for any other reason, Macrocure shareholders will not receive shares of Leap common stock for their Macrocure ordinary shares. If the merger agreement is terminated for any reason, it would be Macrocure's intention to seek other opportunities to combine with a company similar to Leap and/or explore a liquidation of Macrocure. However, if, after failure to consummate the merger, Macrocure remains a stand-alone entity and, particularly, if it fails to consummate a transaction that provides active operations in the near future, NASDAQ could, at some point, determine that Macrocure is a "public shell company" (as defined under Commission rules) and, if it does, seek to delist Macrocure's ordinary shares. There can be no assurance, however, regarding any action that NASDAQ may take in the interim, as to whether Macrocure would be successful in finding another appropriate opportunity or the amount that may be received upon liquidation. So long as Macrocure's shares are listed for trading on NASDAQ and/or registered under the Exchange Act, Macrocure would be required to file and/or submit reports with the Commission.

        See the section entitled "The Merger Agreement—Fees and Expenses" beginning on page 106 of this prospectus.

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        Upon the consummation of the merger, the board of directors of Leap will be comprised of seven members. The members of the board are expected to be:

        The Leap board of directors has determined that all expected members of the board of directors, except Christopher Mirabelli, are independent directors, including for purposes of the rules of the NASDAQ stock market and relevant federal securities laws and regulations.

        Following the consummation of the merger, Leap will have its corporate headquarters in Cambridge, Massachusetts. Dr. Christopher Mirabelli, the current president and chief executive officer of Leap, will continue as the chief executive officer of Leap following the consummation of the merger. Mr. Augustine Lawlor, the current chief operating officer of Leap, will continue as the chief operating officer of Leap following the consummation of the merger. Mr. Douglas E. Onsi, the current chief financial officer of Leap, will continue as the chief financial officer of Leap following the merger.

        Pursuant to the terms of the merger agreement, immediately prior to the consummation of the merger, Leap's charter and bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, to this prospectus. We refer to these, respectively, as the New Leap Charter and the New Leap Bylaws. Prior to the merger, the rights of Macrocure shareholders are governed by the laws of the State of Israel and the articles of association of Macrocure. As a result of becoming shareholders of Leap in the merger, the rights of the former Macrocure shareholders will be governed by the laws of the State of Delaware, the New Leap Charter and the New Leap Bylaws. For more information, see the section entitled "Comparison of Rights of Holders of Leap Shares and Holders of Macrocure Shares" beginning on page 243 of this prospectus.

        The New Leap Charter will, among other things, provide for a staggered board of directors, authorize 100,000,000 shares of common stock, 10,000,000 shares of undesignated preferred stock and effectuate a pre-closing Leap reverse share split, referred to as the "Pre-Closing Leap Share Conversion", whereby each share of Leap common stock outstanding immediately prior to the consummation of the merger will be automatically reclassified and changed into a certain number of shares of Leap common stock at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock. See the section entitled "The Merger—Amendment and Restatement of Leap Charter and Bylaws" beginning on page 84 of this prospectus.

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        Pursuant to the terms of the merger agreement, holders of Macrocure ordinary shares (and holders of any instrument exercisable for Macrocure ordinary shares) will receive shares of Leap common stock (or become a holder of an instrument exercisable for shares of Leap common stock). The number of shares of Leap common stock to be issued to all holders of Macrocure ordinary shares with respect to each such ordinary share will equal the quotient obtained by dividing (i) the product of (a) 0.35 multiplied by the quotient obtained by dividing (I) the aggregate number of shares of Leap common stock outstanding after giving effect to the Pre-Closing Leap Share Conversion, the Recap and the assumed exercise of all outstanding stock options by (II) 0.65, by (ii) the aggregate number of Macrocure ordinary shares, including those issuable upon the exercise of Macrocure warrants, Macrocure options (but not including any out-of-the-money options which, as used herein, refers to those Macrocure options with an exercise price equal to or greater than $10.00, prior to giving effect to the exchange in the merger for shares of Leap common stock) and any other awards under Macrocure's stock option plans, in each case, outstanding immediately prior to the consummation of the merger. This exchange shall be calculated prior to giving effect to (i) a contemplated $10.0 million equity investment into Leap immediately prior to the consummation of the merger committed by certain affiliates of Leap and (ii) the adoption of Leap's 2016 Equity Incentive Plan representing a number of shares of Leap common stock that, together with the out-of-the-money options outstanding at the effective time of the merger, represents 8% of Leap's fully diluted capitalization, such that, on a pro forma basis, based upon the number of shares of Leap common stock to be issued in the merger (including in respect of outstanding Macrocure options and warrants), Macrocure equityholders (other than the holders of the out-of-the-money options) will own approximately 35% of the combined company and Leap equityholders will own approximately 65% of the combined company. However, these ratios are subject to a net cash adjustment, such that if Macrocure's net cash at the effective time of the merger equals less than $22.0 million, there will be a linear, downward adjustment to Macrocure's equityholders' ownership in the combined company (in the extreme, if Macrocure's net cash at the effective time of the merger equals zero, Macrocure's shareholders' ownership in the combined company would equal 13%).

        For illustrative purposes only, assuming Macrocure's net cash was determined to be $22.0 million or more, the exchange ratio for the Macrocure ordinary shares would have been approximately 0.1819 shares of Leap common stock for each Macrocure ordinary share. Therefore, if the merger had been consummated based on such calculation and you owned 1,000 Macrocure ordinary shares as of the effective time of the merger, you would have had the right to receive 181 shares of Leap common stock in exchange for your Macrocure ordinary shares plus cash in lieu of fractional shares. The issuance of the Leap common stock to Macrocure equityholders will be registered with the Commission. Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly. See the section entitled "The Merger—Merger Consideration" beginning on page 72 of this prospectus.

        Each Macrocure option (whether vested or unvested) that is outstanding immediately prior to the consummation of the merger will generally be adjusted such that, at the effective time of the merger, it will be converted into an option to purchase the number of shares of Leap common stock equal to the number of Macrocure ordinary shares subject to the Macrocure option multiplied by the exchange ratio (rounded down to the nearest whole share), at an exercise price per share equal to the exercise price per share of each Macrocure option, divided by the exchange ratio (rounded up to the nearest whole cent).

        In the merger, Leap will assume Macrocure's 2008 and 2013 Share Incentive Plans, referred to herein as the Macrocure Share Incentive Plans, and all obligations of Macrocure under such plans upon

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consummation of the merger. Pursuant to the merger agreement, Leap will deliver appropriate notices setting forth each option holder's rights as soon as practicable after the merger.

        Each Macrocure warrant that is outstanding immediately prior to the consummation of the merger will generally be amended and adjusted such that, at the effective time of the merger, it will be exercisable for that number of shares of Leap common stock equal to the number of Macrocure ordinary shares subject to the Macrocure warrant multiplied by the exchange ratio (rounded down to the nearest whole share), at an exercise price per share equal to the current exercise price of 0.01 New Israeli Shekels, or NIS, divided by the exchange ratio (rounded up to the nearest whole cent). The form of Amendment No. 2 to Warrant, which will implement the foregoing adjustments, is attached as an exhibit to the Registration Statement of which this prospectus forms a part.

        Immediately prior to the effective time of the merger, (i) all preferred stock of Leap then outstanding and (ii) Leap's outstanding convertible promissory notes, will convert into shares of Leap common stock, which we refer to as the "Recap". Immediately thereafter and prior to the effective time of the merger, Leap will undergo a reverse stock split at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock. As a result, at the effective time of the merger, all outstanding shares of Leap capital stock will be shares of Leap common stock. Upon the consummation of the merger, each outstanding Macrocure ordinary share will be converted into the right to receive shares of Leap common stock equal to the exchange ratio, as discussed above. As a result of the foregoing (and prior to giving effect to (i) a contemplated $10.0 million equity investment into Leap committed by certain affiliates of Leap immediately prior to the consummation of the merger, which investment is a condition to the closing of the merger, and (ii) the adoption of Leap's 2016 Equity Incentive Plan immediately after the consummation of the merger, but after giving effect to the stock options to be granted to key executives of Leap in contemplation of the merger), approximately 65% of the outstanding Leap common stock will be held by stockholders and option holders that were holders of Leap common stock and stock options, respectively, immediately prior to the consummation of the merger, and approximately 35% of the Leap common stock will be held by shareholders, option holders and warrant holders that were holders of Macrocure ordinary shares, stock options and warrants, respectively, immediately prior to the consummation of the merger. The foregoing percentage ownership assumes the exercise of all stock options of Macrocure and Leap outstanding as of the effective time of the merger, but excludes (i) out-of-the-money options, (ii) the $10.0 million equity investment and (iii) the adoption of the Leap 2016 Equity Incentive Plan).

        As described herein, the exchange ratio is subject to a net cash adjustment, such that if Macrocure's net cash at the effective time of the merger equals less than $22.0 million, there will be a linear, downward adjustment to Macrocure's equityholders' ownership in the combined company. However, if Macrocure's net cash at the effective time of the merger equals less than $20.0 million, Leap is not obligated to consummate the merger.

        In addition, Leap may also raise additional equity financing above the aforementioned $10.0 million in a private financing that would close simultaneously with the consummation of the merger to further finance its operations. The dilution from any additional equity financing is not reflected in the percentage ownership calculations presented above.

        Additionally, as a result of the merger, Macrocure will no longer be a publicly held company; rather, all shares of Macrocure will be owned by Leap following the merger, leaving Macrocure a wholly owned subsidiary of Leap. Following the consummation of the merger, Macrocure ordinary shares will be delisted from The NASDAQ Global Market and deregistered under the Exchange Act,

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and Macrocure will no longer be required to file reports with the Commission in respect of Macrocure ordinary shares.

        For more information on the Pre-Closing Leap Share Conversion, the Recap and the equity investments, see the sections entitled "The Merger—Pre-Closing Leap Share Conversion and Recapitalization" and "The Merger—Equity Investment" beginning on pages 73 and 70, respectively, of this prospectus.

        Macrocure's directors and officers have certain interests in the merger that may be different from, or in addition to, the interests of Macrocure shareholders generally. See the section entitled "Financial Interests of Macrocure's Directors and Executive Officers in the Merger" beginning on page 224 of this prospectus.

        As soon as reasonably practicable after the effective time of the merger, Leap will cause its exchange agent for the merger to mail a letter of transmittal to each holder of record of a certificate whose shares converted pursuant to the merger into the right to receive the merger consideration. The letter of transmittal will specify that their certificates must be delivered to the exchange agent and will set forth instructions for effecting the surrender of the certificates in exchange for merger consideration.

        After receiving the certificate and a duly completed and validly executed letter of transmittal in accordance with the instructions thereto from Macrocure shareholders, Leap's exchange agent will deliver to each Macrocure shareholder the Leap common stock in physical certificate or uncertificated in book-entry form and any cash payment due in lieu of fractional shares.

        The merger is expected to be a taxable exchange for U.S. federal income tax purposes. Assuming the merger so qualifies, the following U.S. federal income tax consequences generally will result to a participating U.S. holder (as defined in "U.S. Federal Income Tax Considerations"): (i) such holder generally will recognize gain or loss on the receipt of Leap common stock in exchange for Macrocure ordinary shares in the merger; (ii) such holder's aggregate tax basis in the Leap common stock (as defined in "U.S. Federal Income Tax Considerations") received pursuant to the merger will be equal to the fair market value of the Leap common stock received by such U.S. holder on the date Macrocure ordinary shares are exchanged pursuant to the merger and determined in good faith by the Leap board of directors; and (iii) such holder's holding period for the Leap common stock will begin on the day following the date such U.S. holder's Macrocure ordinary shares are exchanged pursuant to the merger.

        For more information on the U.S. federal income tax considerations of the merger, see the section entitled "U.S. Federal Income Tax Considerations" beginning on page 226 of this prospectus. Macrocure shareholders should consult their tax advisors to understand all of the tax consequences of the merger to them.

        In general, under the Israeli Income Tax Ordinance (New Version) 1961, as amended, and the rules and regulations promulgated thereunder, the disposition of shares of an Israeli company is deemed to be a sale of capital assets, unless such shares are held for the purpose of trading. The Israeli Income Tax Ordinance generally imposes a capital gains tax on the sale of capital assets located in

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Israel, including shares in an Israeli resident company, by both residents and non-residents of Israel, unless a specific exemption is available or unless a treaty for the prevention of double taxation between Israel and the seller's country of residence provides otherwise. Assuming Macrocure receives the Israeli tax rulings from the Israel Tax Authority for which Macrocure has applied, the Israeli income tax consequences of the merger shall be in accordance with such tax rulings (if applicable to a particular Macrocure shareholder).

        For more information on the foreign (Israeli, in particular) income tax consequences of the merger, see the section entitled "Material Foreign Tax Consequences—Material Israeli Tax Consequences" beginning on page 231 of this prospectus. Macrocure shareholders should consult their tax advisors to understand all of the foreign (Israeli, in particular) tax consequences of the merger to them.

        If you have additional questions about the merger or need additional copies of this prospectus, please contact Douglas Onsi at (617) 714-0360.

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SUMMARY

         The following summary highlights selected information in this prospectus and may not contain all the information that may be important to you as a Leap stockholder. Accordingly, we encourage you to read carefully this entire prospectus, its exhibits and annexes and the documents referred to herein. Each item in this summary includes a page reference directing you to a more complete description of that topic.

Parties to the Merger (Page 59)

    Macrocure Ltd.
    25 Hasivim Street
    Petach Tikva 4959383, Israel
    +972-54-565-6011

      Macrocure Ltd. was formed as a company in the State of Israel on January 14, 2008 and registered under No. 515506855 with the Israeli Registrar of Companies. Macrocure has operated since its inception as a biotechnology company focused on developing, manufacturing and commercializing novel cell therapy products to address unmet needs.

      Macrocure is subject to the provisions of the Companies Law. Macrocure's corporate headquarters are located at 25 Hasivim Street, Petach Tikva 4959383, Israel. Macrocure's telephone number is +972-54-565-6011 and its web site is located at www.macrocure.com (the information contained therein or linked thereto shall not be considered incorporated by reference in this prospectus). Macrocure's U.S. agent is Puglisi & Associates, located at 850 Library Avenue, Suite 204, Newark, Delaware 19711.

      In August 2014, Macrocure completed its initial public offering, and its ordinary shares began trading on The NASDAQ Global Market under the symbol "MCUR." Following the merger, Macrocure's ordinary shares will be delisted from The NASDAQ Global Market.

    Leap Therapeutics, Inc.
    47 Thorndike Street, Suite B1-1
    Cambridge, MA 02141
    617-714-0360

      Leap Therapeutics, Inc. was originally incorporated on January 3, 2011 as Dekkun Corporation, a Delaware corporation. Dekkun Corporation's name was changed to HealthCare Pharmaceuticals, Inc. in May 2014. On November 16, 2015, HealthCare Pharmaceuticals, Inc. changed its name to Leap Therapeutics, Inc.

      Leap is a biopharmaceutical company acquiring and developing novel therapeutics at the leading edge of cancer biology. Leap's approach is designed to target compelling tumor-promoting and immuno-oncology pathways to generate durable clinical benefit and enhanced outcomes for patients. Leap's programs are monoclonal antibodies that target key cellular pathways that enable cancer to grow and spread and specific mechanisms that activate the body's immune system to identify and attack cancer.

      The mailing address of Leap's principal executive office is 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141. Leap's telephone number is 617-714-0360. Leap's website address is www.leaptx.com (the information contained therein or linked thereto shall not be considered incorporated by reference in this prospectus).

      Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

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    M-CO Merger Sub Ltd.
    c/o Leap Therapeutics, Inc.
    47 Thorndike Street, Suite B1-1
    Cambridge, MA 02141
    617-714-0360

      M-CO Merger Sub Ltd. is a wholly owned subsidiary of Leap formed solely for the purpose of effectuating the merger described herein. Merger Sub was formed under the laws of the State of Israel and registered under No. 515506855 with the Israeli Registrar of Companies as a direct wholly owned subsidiary of Leap under the laws of Israel on August 15, 2016. Merger Sub owns no material assets and does not operate any business.

      The mailing address of Merger Sub's principal executive office is c/o Leap Therapeutics, Inc., 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141. Its telephone number is 617-714-0360.

      Upon consummation of the merger, Merger Sub will be merged with and into Macrocure and Macrocure will be the surviving corporation and be a wholly owned subsidiary of Leap. Merger Sub will then cease to exist.

General Information Concerning the Merger and Related Agreements (Page 60)

        The terms and conditions of the merger are contained in the merger agreement, a copy of which is attached as Annex A to this prospectus. We encourage you to read the merger agreement carefully and in its entirety, as it is the legal document that governs the merger.

        Pursuant to the merger agreement, at the effective time of the merger, Merger Sub will be merged with and into Macrocure, with Macrocure surviving the merger as a wholly owned subsidiary of Leap. Merger Sub will then cease to exist. Leap plans to submit an application to list its common stock on the NASDAQ stock market under the symbol "LPTX". Leap expects that, on or prior to the consummation of the merger, Leap common stock will be listed on the NASDAQ stock market under the symbol "LPTX". Following the merger, Macrocure ordinary shares will be delisted from the NASDAQ stock market, deregistered under the Exchange Act and will cease to be publicly traded.

Merger Consideration (Page 72)

        At the effective time of the merger, each outstanding Macrocure ordinary share will be converted into the right to receive a number of shares of Leap common stock based on an exchange ratio as set forth in the merger agreement.

Pre-Closing Leap Share Conversion and Recapitalization (Page 73)

        Pursuant to the terms of the merger agreement, immediately prior to the effective time of the merger, Leap's charter and bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, of this prospectus. Pursuant to the terms of the merger agreement, immediately prior to the amendment of the Leap charter, each issued and outstanding share of Leap preferred stock and each outstanding Leap convertible promissory note will convert into shares of Leap common stock (the Recap).

        In connection with the amendment of the Leap charter, upon filing of the New Charter with the Secretary of State of Delaware, each share of Leap common stock issued and outstanding immediately prior to the effective time of the merger (including shares subject to then outstanding options) will undergo a reverse stock split at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock (the Pre-Closing Leap Share Conversion).

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Exchange of Shares in the Merger (Page 91)

        Pursuant to the terms of the merger agreement, holders of Macrocure ordinary shares (or instruments exercisable for Macrocure ordinary shares) will receive shares of Leap common stock (or become instruments exercisable for shares of Leap common stock). The number of shares of Leap common stock to be issued to all holders of Macrocure ordinary shares with respect to each such ordinary share will equal the quotient of (i) the product of (a) 0.35 multiplied by (b) the quotient of (I) the aggregate number of shares of Leap common stock outstanding after giving effect to the Pre-Closing Leap Share Conversion, the Recap and the assumed exercise of all outstanding stock options, divided by (II) 0.65, divided by (ii) the aggregate number of Macrocure ordinary shares, including those issuable upon the exercise of Macrocure warrants, Macrocure options (but not including any out-of-the-money options) and any other awards under Macrocure's stock option plans, in each case, outstanding immediately prior to the consummation of the merger. This exchange shall be calculated prior to giving effect to (i) a contemplated $10.0 million equity investment into Leap immediately prior to the consummation of the merger committed to by certain affiliates of HealthCare Ventures and (ii) the creation of Leap's 2016 Equity Incentive Plan representing a number of shares of Leap common stock that, together with the out-of-the-money options outstanding at the effective time of the merger, represents 8% of Leap's fully diluted capitalization, such that, on a pro forma basis, based upon the number of shares of Leap common stock to be issued in the merger (including in respect of outstanding Macrocure options and warrants), Macrocure equityholders will own approximately 35% of the combined company and Leap equityholders will own approximately 65% of the combined company. However, these ratios are subject to a net cash adjustment, such that if Macrocure's net cash at the effective time of the merger equals less than $22.0 million, there will be a linear, downward adjustment to Macrocure's equityholders' ownership in the combined company (in the extreme, if Macrocure's net cash at the effective time of the merger equals zero, Macrocure's shareholders' ownership in the combined company would equal 13%).

Recommendation of the Macrocure Board (Page 64)

        After careful consideration, on August 29, 2016, the Macrocure board of directors unanimously (with one director absent) (i) determined that the merger agreement, the merger and the other transactions contemplated by the merger agreement are fair to and in the best interests of Macrocure and its shareholders, (ii) approved and declared it advisable that Macrocure enter into the merger agreement and (iii) adopted the merger agreement, the merger and the transactions contemplated thereby. Accordingly, the Macrocure board unanimously recommends that the Macrocure shareholders vote (i) "FOR" approval of the merger agreement and (ii) "FOR" all other proposals to be submitted for shareholder approval in connection with the merger agreement and described in this prospectus and the proxy statement of Macrocure that will be mailed to shareholders in connection with the Macrocure Shareholder Meeting. For more information on Macrocure's reasons for the merger and the recommendation of the Macrocure board, see the section entitled "The Merger—Recommendation of the Macrocure Board; Macrocure's Reasons for the Merger." Macrocure will mail its proxy statement, together with a copy of this prospectus, to its shareholders on or about                        , 2016. A copy of the Macrocure proxy statement will be submitted by Macrocure to the Commission as an exhibit to a Report of Foreign Private Issuer on Form 6-K at the time it is first mailed to Macrocure shareholders.

Opinion of Macrocure's Financial Advisor (Page 73)

        At the August 29, 2016, meeting of the Macrocure board of directors, representatives of Raymond James rendered Raymond James' oral opinion, which was subsequently confirmed by delivery of a written opinion to the Macrocure board of directors, dated August 29, 2016, as to the fairness, as of such date, from a financial point of view, to the holders of Macrocure ordinary shares of the merger consideration to be paid by Leap to the holders of the Macrocure ordinary shares, such that

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approximately 32.0% of fully paid and non-assessable shares of Leap common stock will be received by such holders (including, for these purposes, warrantholders and optionholders (but not including holders of the out-of-the-money options) in the merger pursuant to the merger agreement, calculated after giving effect to the adoption of Leap's 2016 Equity Incentive Plan, but not giving effect to a contemplated $10.0 million equity investment into Leap immediately prior to the consummation of the merger committed by certain affiliates of HealthCare Ventures, and subject to adjustment based on the final amount of Macrocure's net cash as defined in the merger agreement. Additionally, at Macrocure's direction and with Macrocure's consent, Raymond James did not consider the terms of the distributed royalty rights in forming its opinion other than to the extent the ongoing costs of such royalty rights to Leap are incorporated into the projections that Raymond James used in its discounted cash flow analysis.

        The full text of the written opinion of Raymond James, dated August 29, 2016, which sets forth, among other things, the various qualifications, assumptions and limitations on the scope of the review undertaken, is attached as Annex B to this prospectus. Raymond James provided its opinion for the information and assistance of the Macrocure board of directors (solely in its capacity as such) in connection with, and for purposes of, its consideration of the merger and its opinion only addresses whether the approximately 32.0% of Leap common stock to be received by the holders of the Macrocure ordinary shares in the merger pursuant to the merger agreement was fair, from a financial point of view, to such holders. The opinion of Raymond James did not address any other term or aspect of the merger agreement or the merger contemplated thereby. The Raymond James opinion does not constitute a recommendation to the Macrocure board or any holder of Macrocure ordinary shares as to how the board, such shareholder or any other person should vote or otherwise act with respect to the merger or any other matter.

Ownership of Leap Following the Merger (Page 83)

        After giving effect to the $10.0 million equity investment, the Pre-Closing Leap Share Conversion, the Recap, the consummation of the merger, but not the adoption of Leap's 2016 Equity Incentive Plan, it is anticipated that, at the effective time of the merger Leap equityholders will own approximately 68.2% of the outstanding shares of Leap common stock and Macrocure equityholders will own approximately 31.8% of the outstanding shares of Leap common stock, in each case on a fully diluted basis (i.e., assuming all outstanding stock options and warrants were exercised, other than the out-of-the-money options).

        In addition, Leap may also raise additional equity financing above the aforementioned $10.0 million in a private financing that would close simultaneously with the consummation of the merger to further finance its operations. The dilution from any additional equity financing is not reflected in the percentage ownership calculations presented above.

Headquarters and Management of Leap Following the Merger (Page 83)

    Name of Company; Headquarters

        Following the merger, the parent company shall continue to be called Leap Therapeutics, Inc. and Macrocure Ltd. will exist as Leap's wholly owned subsidiary. Leap's headquarters will be at 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts.

    Board of Directors

        Leap and Macrocure have agreed that upon the consummation of the merger, the board of directors of Leap will be comprised of seven members. The members of the board are expected to be:

    Christopher Mirabelli, currently the President, CEO and a director of Leap

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    Thomas Dietz, currently a director of Leap

    John Littlechild, currently a director of Leap

    James Cavanaugh, currently a director of Leap

    Joseph Loscalzo, currently a director of Leap

    Nissim Mashiach, the President and CEO of Macrocure

    William Li, formerly an advisor to Macrocure

        The Leap board of directors has determined that all expected members of the board of directors, except Christopher Mirabelli, are independent directors, including for purposes of the rules of the NASDAQ stock market and relevant federal securities laws and regulations.

    Management

        Dr. Christopher Mirabelli, the current president and chief executive officer of Leap, will continue as the chief executive officer of Leap following the consummation of the merger. Mr. Augustine Lawlor, the current chief operating officer of Leap, will continue as the chief operating officer of Leap following the consummation of the merger. Mr. Douglas E. Onsi, the current chief financial officer of Leap, will continue as the chief financial officer of Leap following the merger.

Financial Interests of Macrocure's Directors and Executive Officers in the Merger (Page 224)

        In considering the recommendation of the Macrocure board with respect to the merger proposal, Macrocure shareholders should be aware that the executive officers and directors of Macrocure have certain interests in the merger that may be different from, or in addition to, the interests of Macrocure shareholders generally. The Macrocure board was aware of these interests and considered them, among other matters, in approving the merger agreement and the transactions contemplated thereby and making its recommendation that Macrocure shareholders vote in favor of the merger proposal.

        These interests include, among others:

    under the merger agreement, Macrocure stock-based awards and warrants (including those held by the executive officers and directors) will convert into Leap stock-based awards of the corresponding type with appropriate adjustments as to the exercise price and the number of shares of Leap common stock issuable upon exercise thereof;

    the vesting of any unvested options to purchase Macrocure ordinary shares held by Macrocure's executive officers and directors upon consummation of the merger and the extension of post-employment exercise periods;

    subject to approval by shareholders at the Macrocure Shareholder Meeting, two of Macrocure's independent directors will each receive a grant of options to purchase 36,662 Macrocure ordinary shares, at an exercise price equal to the closing market price of the Macrocure ordinary shares on the date of the Macrocure Shareholder Meeting, which will vest in an accelerated manner at (and subject to the occurrence of) the effective time of the merger;

    subject to approval by shareholders at the Macrocure Shareholder Meeting, Macrocure's chief executive officer, or the Macrocure CEO, will be entitled to certain compensation, including: (i) effective upon, and subject to, the consummation of the merger: (a) a grant of options to purchase 150,000 Macrocure ordinary shares, at an exercise price equal to the closing market price of the Macrocure ordinary shares on the date of the Macrocure Shareholder Meeting, which will vest in an accelerated manner at the effective time of the merger, and (b) payment of a $300,000 cash bonus, subject to Macrocure's implied value being assessed at a certain level for

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      purposes of the merger, which requirement may be waived at the discretion of Macrocure's Chairman of the Board, after consultation with the compensation committee of Macrocure's board of directors;

    the Macrocure CEO will receive a one-time "make whole" payment in an amount equal to the base salary voluntarily foregone by him in the recent past (consisting of $10,000 of foregone salary per month), commencing on December 1, 2015 through the month in which the merger is consummated;

    each of the Macrocure CEO and Macrocure's chief financial officer will be entitled under applicable Israeli law to continue receiving their monthly base salary (and, in the case of the chief financial officer, social benefits) during three-month and nine-month notice periods, respectively, following termination of their respective employments for Macrocure upon consummation of the merger;

    pursuant to the requirements of the merger agreement, Macrocure's executive officers and directors will be entitled to ongoing indemnification by Leap against any costs, expenses, damages, liabilities and the like incurred in connection with any claims or proceedings arising out of or pertaining to matters related to their role as such, in each case existing or occurring at or prior to the effective time of the merger;

    pursuant to the requirements of the merger agreement and subject to the approval by shareholders at the Macrocure Shareholder Meeting, Macrocure's executive officers and directors will be covered under a "tail" insurance policy that will provide coverage to them at the same level as under Macrocure's existing insurance for its executive officers and directors, until the seventh anniversary of the effective time of the merger; and

    the Macrocure CEO will be appointed to Leap's board of directors upon consummation of the merger.

        For additional details regarding these interests, see the section entitled "Financial Interests of Macrocure's Directors and Executive Officers in the merger."

Regulatory Approvals (Page 85)

        Macrocure and Merger Sub each filed with the Israeli Companies Registrar their respective notifications required under the Companies Law with respect to the proposed merger on August 31, 2016. The waiting period, which commenced with the filing of the notifications under the Companies Law, will expire 50 calendar days after such filings, unless otherwise extended or terminated or waived, although the merger may not be effective until the expiration of 30 days from the date of the approval of the merger by Macrocure's shareholders.

        Leap and Macrocure have agreed to take, or cause to be taken, all actions, and do, or cause to be done, and assist and cooperate with the other in doing, all things necessary to avoid or eliminate each and every legal impediment that may be asserted under Israeli corporate law so as to enable the parties to the merger agreement to consummate and make effective, as promptly as practicable, the merger and the other transactions contemplated by the merger agreement in accordance with its terms. However, Leap and Macrocure and their respective subsidiaries are not required under the merger agreement to agree to or otherwise be required to commit to, execute or consummate any sale, divestiture, disposition or arrangement if doing so would, individually or in the aggregate, reasonably be expected to have a material adverse effect on the business, assets, results of operations or financial condition of Leap, Macrocure and their respective subsidiaries, taken as a whole. Further, the parties are not required to agree to any such actions with respect to the business or operations of Leap or Macrocure and their respective subsidiaries unless their effectiveness is conditioned on the closing of the merger.

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No Appraisal Rights (Page 234)

        Macrocure shareholders will not have appraisal rights under the Companies Law with respect to the merger.

NASDAQ Market Listing (Page 86)

        Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

Conditions to Consummation of the Merger (Page 104)

        The obligations of Leap, Merger Sub and Macrocure to effect the merger are subject to the satisfaction or waiver by each of the parties to the merger agreement of the following conditions at or prior to the effective time:

    approval of the merger proposal by affirmative vote of holders of a majority of the outstanding Macrocure ordinary shares present and entitled to vote at the Macrocure Shareholder Meeting;

    authorization for the listing on the NASDAQ stock market of the shares of Leap common stock to be issued to Macrocure shareholders in connection with the merger, subject to official notice of issuance;

    obtaining required regulatory approvals;

    effectiveness of the Registration Statement of which this prospectus forms a part and no stop order suspending the effectiveness of the Registration Statement having been issued or proceedings for that purpose having been initiated or threatened by the Commission;

    no material order, injunction or decree issued by any court or agency of competent jurisdiction or other legal restraint or prohibition preventing the consummation of the merger or any of the other transactions contemplated by the merger agreement being in effect; and

    agreement upon the net cash calculation and the Leap net accounts payable calculation or the independent registered public accountant shall have delivered its report with respect to the net cash calculation and the Leap net accounts payable calculation, as described in "The Merger Agreement—Conditions to Consummation of the Merger".

        In addition, Leap's obligation to consummate the merger is subject to the satisfaction or waiver of the following conditions at or prior to the effective time:

    the representations and warranties of Macrocure being true and correct to the extent required, and subject to the applicable materiality standards set forth in, the merger agreement, together with the receipt by Leap of a certificate executed by Macrocure's chief executive officer or chief financial officer to such effect;

    Macrocure having performed in all material respects all obligations required to be performed by it under the merger agreement at or prior to the closing date of the merger, together with the receipt by Leap of a certificate executed by Macrocure's chief executive officer or chief financial officer to such effect;

    the net cash of Macrocure at the closing of the merger is not less than $20 million; and

    the absence of a material adverse effect having occurred with respect to Macrocure.

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        In addition, Macrocure's obligation to consummate the merger is subject to the satisfaction or waiver of the following conditions at or prior to the effective time:

    the representations and warranties of Leap being true and correct to the extent required, and subject to the applicable materiality standards set forth in, the merger agreement, together with the receipt by Macrocure of a certificate executed by Leap's chief executive officer or chief financial officer to such effect;

    Leap having performed in all material respects all obligations required to be performed by it under the merger agreement at or prior to the closing date of the merger, together with the receipt by Macrocure of a certificate executed by Leap's chief executive officer or chief financial officer to such effect;

    the net accounts payable of Leap at the closing of the merger are not greater than $1.0 million, as determined in accordance with generally accepted accounting principles in the United States ("GAAP") consistent with past practices;

    After giving effect to the conversion of Leap Notes into Leap common stock, Leap shall not have any Indebtedness (as defined in the merger agreement);

    the absence of a material adverse effect having occurred with respect to Leap;

    the employment agreements with key executives of Leap shall remain in full force and effect; and

    the adoption of Leap's 2016 Equity Incentive Plan, representing a number of shares of Leap common stock that, together with the out-of-the-money options outstanding at the effective time of the merger, represents 8% of Leap's fully diluted capitalization; and

    Leap having obtained the equity investment of at least $10.0 million from funds affiliated with HealthCare Ventures or its designees at a price per share based on a pre-money valuation of $100 million (exclusive of an unallocated option pool reserved under Leap's 2016 Equity Incentive Plan).

        For a more complete summary of the conditions that must be satisfied or waived prior to completion of the merger, see the section entitled "The Merger Agreement—Conditions to Consummation of the Merger" beginning on Page 104 of this prospectus.

No Solicitation or Negotiation of Acquisition Proposals (Page 97)

        Macrocure has agreed that it will not, and it will cause its subsidiaries and its controlled affiliates' respective directors, officers and employees and investment bankers, financial advisors, attorneys, accountants and other advisors, agents and representatives retained in connection with the merger and the other transactions contemplated by the merger agreement, which we refer to as transaction representatives, and will use its reasonable best efforts to cause its other investment bankers, financial advisors, attorneys, accountants and other advisors, agents and representatives, which we refer to as other representatives, not to, and on becoming aware of it will use its best efforts to stop any such persons from continuing to, directly or indirectly:

    solicit, initiate or knowingly facilitate any inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, a takeover proposal (as defined in the section entitled "The Merger Agreement—No Solicitation of Takeover Proposals" beginning on Page 97 of this prospectus);

    engage or otherwise participate in any discussions or negotiations regarding, or furnish to any person any non-public information in connection with, or for the purposes of facilitating, any

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      inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, a takeover proposal; or

    execute or enter into any acquisition agreement (as defined in the section entitled "The Merger Agreement—No Solicitation of Takeover Proposals" beginning on Page 97 of this prospectus).

        The merger agreement requires that Macrocure promptly (but in any event within 24 hours) notify Leap of the receipt of any takeover proposal and identify the person or group making the takeover proposal. In addition, Macrocure is required to provide to Leap an unredacted copy of the takeover proposal, if made in writing, and a written summary of all material terms and conditions of any such takeover proposal, to the extent not made in writing.

Alternative Proposals (Page 97)

        Notwithstanding the restrictions discussed above in "No Solicitation or Negotiation of Acquisition Proposals", prior to the approval of the merger proposal by Macrocure's shareholders at the Macrocure Shareholder Meeting, Macrocure may, after providing notice to Leap:

    enter into a confidentiality agreement no less restrictive to Macrocure than that agreement between Macrocure and Leap (other than for any standstill provisions) and furnish information with respect to Macrocure and its subsidiaries to a person or group making a takeover proposal not resulting in any material respect from a breach of the non-solicitation provisions of the merger agreement; and

    engage in or otherwise participate in discussions with the person or group making the takeover proposal,

        in each case if the Macrocure board determines in good faith (after consultation with its outside counsel and financial advisors):

    that such takeover proposal constitutes or is reasonably likely to lead to a superior proposal (as defined in the section entitled "The Merger Agreement—No Solicitation of Takeover Proposals" beginning on Page 97 of this prospectus); and

    that the failure to take either such action would be reasonably likely to be inconsistent with the fiduciary duties of the Macrocure board under applicable law.

No Change in Recommendation or Alternative Acquisition (Page 97)

        Subject to certain exceptions described below, neither the Macrocure board nor any committee thereof will:

    withhold, withdraw or modify in a manner adverse to Leap the recommendation to Macrocure shareholders that they vote in favor of the approval of the merger proposal at the Macrocure Shareholder Meeting;

    approve or recommend, or publicly propose to approve or recommend, any takeover proposal;

    refrain from recommending against any takeover proposal that is a tender offer or an exchange offer within ten business days after it commences (we refer to any of these first three bullets as an adverse recommendation change); or

    enter into or propose publicly to execute or enter into (or cause or permit Macrocure or any of its subsidiaries to execute or enter into or propose publicly to execute or enter into) an acquisition agreement.

        Macrocure may, however, make an adverse recommendation change or terminate the merger agreement and enter into an acquisition in respect of a takeover proposal, if the Macrocure board or

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any committee thereof determines in good faith (after consultation with its outside counsel and financial advisor) that to do otherwise would be reasonably likely to be inconsistent with its fiduciary duties under applicable law and, if such action is being taken in response to a takeover proposal, that such takeover proposal constitutes a superior proposal. Prior to any such action being taken, Macrocure must provide written notice to Leap advising Leap that the Macrocure board (or any committee thereof) intends to take such action and the reasons therefor and take the other actions described in the section entitled "The Merger Agreement—No Solicitation of Takeover Proposals" beginning on Page 97 of this prospectus, including negotiating, at the request of Leap, in good faith with respect to any changes to the terms of the merger agreement during a four business day period after delivery of such written notice. For any such termination to be valid under the merger agreement, Macrocure must pay Leap a termination fee of $1.2 million, plus reimbursement of expenses of up to $0.75 million, prior to, or substantially concurrently with, entering into an acquisition agreement in respect of such takeover proposal.

Termination of the Merger Agreement (Page 105)

        The merger agreement may be terminated at any time by Leap or Macrocure prior to the effective time of the merger under the following circumstances:

    by mutual written consent;

    if any governmental entity issues a final and nonappealable order permanently enjoining or otherwise prohibiting the consummation of the merger or the other transactions contemplated by the merger agreement;

    if the Macrocure shareholders fail to approve the merger proposal at the special meeting;

    if the merger is not consummated by January 31, 2017, provided that failure to consummate the merger is not due to a breach of Leap or Macrocure's obligations under the merger agreement, subject to a possible extension of up to 90 days and certain potential limitations on Macrocure's right to terminate under this provision if the Section 104H tax ruling has not been received or the failure to receive Macrocure shareholder approval was as a result of a breach of a Macrocure voting agreement, all as described herein;

    subject to cure rights, if there shall have been a breach of any of the covenants or agreements or any inaccuracy of any of the representations or warranties of the other party, such that the conditions to the terminating party's obligations to complete the merger would not be satisfied; and

    if Macrocure has not received, by the end date, as extended, referenced above, the Section 104H tax ruling from the Israeli Tax Authorities (as further described in the section entitled "The Merger Agreement—Israeli Tax Rulings" beginning on page 102 of this prospectus), subject to certain limitations on Leap's right to terminate under this provision if other conditions to closing remain unsatisfied.

        Additionally, the merger agreement may be terminated:

    by Leap if, prior to receiving the approval of the Macrocure shareholders, Macrocure's board adversely changes its recommendation that Macrocure's shareholders approve the merger and the related transactions; and

    by Macrocure any time prior to receiving the approval of the Macrocure shareholders should it enter into an acquisition agreement with a third party in accordance with the non-solicitation provisions of the merger agreement.

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Fees and Expenses (Page 106)

        Macrocure will pay Leap a termination fee equal to $1.2 million, plus an expense fee equal to the lesser of (i) $750,000 or (ii) all reasonable out-of-pocket expenses incurred by Leap and Merger Sub in connection with the merger agreement and related activities, in the event that (a) Macrocure enters into any acquisition agreement within 12 months after Leap terminates the merger agreement for Macrocure's failure to obtain shareholder approval of the merger, (b) Macrocure terminates the merger agreement to accept a superior takeover proposal prior to obtaining shareholder approval of the merger or (c) Leap terminates the merger agreement in the event Macrocure's board adversely changes its recommendation that its shareholders approve the merger for any reason other than a material adverse effect on Leap.

        Macrocure will pay Leap a termination fee equal to $1.6 million should Leap terminate the merger agreement on or after January 31, 2017 due to Macrocure's failure to receive the Section 104H Tax Ruling described under the section "The Merger Agreement—Israeli Tax Rulings" beginning on Page 102.

Related Transactions and Agreements (Page 70)

    Equity Investment (Page 70)

        In connection with the merger, certain existing stockholders of Leap affiliated with HealthCare Ventures have committed to purchase, or cause the purchase of, newly issued Leap common stock immediately prior to the amendment of the Leap charter as described below(which amendment will occur immediately prior to the consummation of the merger) for an aggregate purchase price of at least $10.0 million.

        For more information on the equity investment, see the section entitled "The Merger—Related Transactions and Agreements—Equity Investment" beginning on Page 70 of this prospectus.

    Voting Agreements (Page 71)

        In connection with the execution of the merger agreement, all of the stockholders of Leap and certain equityholders of Macrocure ordinary shares, representing more than 50% of the voting power of the issued and outstanding shares of Macrocure (calculated on a fully diluted basis, treating as exercised all options and warrants of Macrocure that are, or will become prior to the Macrocure Shareholder Meeting, convertible, exercisable or exchangeable for Macrocure ordinary shares), have entered into voting agreements, pursuant to which the stockholders or equityholders, as the case may be, have agreed, subject to the terms of the merger agreement, to vote or cause to be voted all of the shares of capital stock of Leap or Macrocure, as the case may be, held of record or beneficially owned by such stockholder or equityholder in favor of (i) the adoption or approval of the merger agreement, in the case of the stockholders of Leap, (ii) in favor of the approval of the shareholder proposals to be presented at the Macrocure Shareholder Meeting, in the case of the equityholders of Macrocure, and (iii) in either case, to take any other actions required of them to consummate the transactions contemplated by the merger agreement.

        For more information on the Voting Agreement, see the section entitled "The Merger—Related Transactions and Agreements—Voting Agreement" beginning on Page 71 of this prospectus.

    Royalty Agreement (Page 71)

        In connection with the merger and the other transactions contemplated by the merger agreement, Leap will declare a special distribution to each of its holders of common stock outstanding immediately prior to the effective time of the merger. Holders of Macrocure ordinary shares will not be participating in the distribution. The special distribution will consist of royalty rights, the terms of which

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are set forth in the Royalty Agreement attached as an exhibit to the Registration Statement of which this prospectus forms a part.

        For more information on the Royalty Agreement, see the section entitled "The Merger—Related Transactions and Agreements—Royalty Agreement" beginning on Page 71 of this prospectus.

Accounting Treatment (Page 86)

        The merger is being accounted for as an in-substance recapitalization of Leap, as the assets and liabilities being acquired consist almost entirely of cash. For more information on the Accounting Treatment see the section entitled "The Merger—Accounting Treatment" beginning on Page 86 of this prospectus.

U.S. Federal Income Tax Considerations (Page 226 )

        The merger is expected to be a taxable exchange for U.S. federal income tax purposes. Assuming the merger so qualifies, the following U.S. federal income tax consequences generally will result to a participating U.S. holder (as defined in "U.S. Federal Income Tax Considerations"): (i) such holder generally will recognize gain or loss on the receipt of Leap common stock in exchange for Macrocure ordinary shares in the merger; (ii) such holder's aggregate tax basis in the Leap common stock (as defined in "U.S. Federal Income Tax Considerations") received pursuant to the merger will be equal to the fair market value of the Leap common stock received by such U.S. holder on the date Macrocure ordinary shares are exchanged pursuant to the merger and determined in good faith by the Leap board of directors; and (iii) such holder's holding period for the Leap common stock will begin on the day following the date such U.S. holder's Macrocure ordinary shares are exchanged pursuant to the merger.

        For more information on the U.S. federal income tax considerations of the merger, see the section entitled "U.S. Federal Income Tax Considerations" beginning on page 226 of this prospectus. Macrocure shareholders should consult their tax advisors to understand all of the tax consequences of the merger to them.

Material Foreign Tax Consequences of the Merger (Page 231)

        In general, under the Israeli Income Tax Ordinance (New Version) 1961, as amended, and the rules and regulations promulgated thereunder, the disposition of shares of an Israeli company is deemed to be a sale of capital assets, unless such shares are held for the purpose of trading. The Israeli Income Tax Ordinance generally imposes a capital gains tax on the sale of capital assets located in Israel, including shares in an Israeli resident company, by both residents and non-residents of Israel, unless a specific exemption is available or unless a treaty for the prevention of double taxation between Israel and the seller's country of residence provides otherwise. Assuming Macrocure receives the Israeli tax rulings from the Israel Tax Authority for which Macrocure has applied, the Israeli income tax consequences of the merger shall be in accordance with such tax rulings (if applicable to a particular Macrocure shareholder).

        For more information on the foreign (Israeli, in particular) income tax consequences of the merger, see the section entitled "Material Foreign Tax Consequences—Material Israeli Tax Consequences" beginning on page 231 of this prospectus. Macrocure shareholders should consult their tax advisors to understand all of the foreign (Israeli, in particular) tax consequences of the merger to them.

Federal Securities Law Consequences (Page 86)

        All Leap common stock received by Macrocure shareholders upon consummation of the merger will be freely tradable without restriction under the Securities Act, except that Leap common stock

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received in the merger by persons who become affiliates of Leap for purposes of Rule 144 under the Securities Act may be resold by them only in transactions permitted by Rule 144, or as otherwise permitted under the Securities Act. For more information regarding the federal securities law consequences see the section entitled "The Merger—and Federal Securities Law Consequences" beginning on page 86 of this prospectus.

Amendment and Restatement of Leap Charter and Bylaws (Page 84 )

        Pursuant to the terms of the merger agreement, immediately prior to the consummation of the merger, Leap's charter and bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, of this prospectus. We refer to these as the New Leap Charter and the New Leap Bylaws. The New Leap Charter will, among other things, provide for a staggered board of directors, authorize 100,000,000 shares of common stock, 10,000,000 shares of undesignated preferred stock and effectuate the Pre-Closing Leap Share Conversion whereby each share of Leap common stock issued and outstanding immediately prior to the effective time of the merger (including shares subject to then outstanding options) will undergo a reverse stock split at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock.

Comparison of Rights of Leap Shareholders and Macrocure Shareholders (Page 243)

        The rights of Macrocure shareholders are governed by Macrocure's Articles of Association, which we refer to as the Macrocure Charter, and by the Companies Law. Pursuant to the terms of the merger agreement, immediately prior to the closing of the merger, Leap's Charter and Bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, of this prospectus. As a result, your rights as a stockholder of Leap following the merger will be governed by the New Leap Charter, by the New Leap Bylaws and by the DGCL. Your rights under the New Leap Charter, the New Leap Bylaws and the DGCL will differ in certain material respects from your rights under the Macrocure Charter and the Companies Law. For more detailed information regarding a comparison of your rights as a shareholder of Macrocure and as a stockholder of Leap, see the section entitled "Comparison of Rights of Leap Stockholders and Macrocure Shareholders" beginning on Page 243 of this prospectus.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

        This prospectus includes forward-looking statements, which reflect our current views with respect to, among other things, our operations and financial performance. You can identify these forward-looking statements by use of words such as "believes," "estimates," "anticipates," "expects," "plans," "projects," "intends," "potential," "may," "could," "might," "will," "should," "approximately," "intends," "predicts," or the negative version of these words or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Forward-looking statements appear in a number of places throughout this prospectus and include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations concerning, among other things, our ability and plan to develop and commercialize DKN-01 and TRX518; status, timing and results of pre-clinical studies and clinical trials; the potential benefits of DKN-01 and TRX518; the timing of our development programs and seeking regulatory approval of DKN-01 and TRX518; our ability to obtain and maintain regulatory approval; our estimates of expenses and future revenues and profitability; our estimates regarding our capital requirements and our needs for additional financing; our estimates of the size of the potential markets for DKN-01 and TRX518; our ability to attract collaborators with acceptable development, regulatory and commercial expertise; the benefits to be derived from any collaborations, license agreements, and other acquisition efforts, including those relating to the development and commercialization of DKN-01 and TRX518; sources of revenues and anticipated revenues, including contributions from any collaborations or license agreements for the development and commercialization of products; our ability to create an effective sales and marketing infrastructure if we elect to market and sell DKN-01 and TRX518 directly; the rate and degree of market acceptance of DKN-01 and TRX518; the timing and amount or reimbursement for DKN-01 and TRX518; the success of other competing therapies that may become available; the manufacturing capacity for DKN-01 and TRX518; our intellectual property position; our ability to maintain and protect our intellectual property rights; our results of operations, financial condition, liquidity, prospects, and growth and strategies; the industry in which we operate; and the trends that may affect the industry or us.

        By their nature, forward-looking statements involve risks and uncertainties because they relate to events, competitive dynamics and industry change, and depend on the economic circumstances that may or may not occur in the future or may occur on longer or shorter timelines than anticipated. Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus, we caution you that forward-looking statements are not guarantees of future performance and that our actual results of operations, financial condition and liquidity, and the development of the industry in which we operate may differ materially from the forward-looking statements contained in this prospectus. In addition, even if our results of operations, financial condition and liquidity, and events in the industry in which we operate are consistent with the forward-looking statements contained in this prospectus, they may not be predictive of results or developments in future periods.

        Actual results could differ materially from our forward-looking statements due to a number of factors, including risks related to:

    our estimates regarding expenses, future revenues, capital requirements and needs for additional financing;

    the opinion of our independent registered public accounting firm as to our ability to continue as a going concern for the next 12 months;

    the success and timing of our pre-clinical studies and clinical trials;

    the potential that results of pre-clinical studies and clinical trials indicate DKN-01 and TRX518 are unsafe or ineffective;

    our exposure to business disruptions;

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    our dependence on third parties in the conduct of our pre-clinical studies, manufacturing activities and clinical trials;

    the difficulties and expenses associated with obtaining and maintaining regulatory approval of DKN-01 and TRX518, and the labeling under any approval we may obtain;

    our plans and ability to develop and commercialize DKN-01 and TRX518;

    our failure to recruit or retain key scientific or management personnel or to retain our executive officers;

    the size and growth of the potential markets for DKN-01 and TRX518, market acceptance of DKN-01 and TRX518 and our ability to serve those markets;

    legal and regulatory developments in the U.S. and foreign countries;

    our ability to limit our exposure to product liability lawsuits;

    our exposure to additional scrutiny as a public company;

    obtaining and maintaining intellectual property protection for DKN-01 and TRX518;

    recently enacted and future legislation regarding the healthcare system; and

    the success of competing therapies and products that are or become available.

        DKN-01 and TRX518 are investigational drugs undergoing clinical development and have not been approved by the U.S. Food and Drug Administration (the "FDA"), nor been submitted to the FDA for approval. DKN-01 and TRX518 have not been, and may never be, approved by any regulatory agency or marketed anywhere in the world. Statements contained in this prospectus should not be deemed to be promotional.

        Any forward-looking statements that we make in this prospectus speak only as of the date of such statement, and we undertake no obligation to update such statements to reflect events or circumstances after the date of this prospectus or to reflect the occurrence of unanticipated events. Comparisons of results for current and any prior periods are not intended to express any future trends or indications of future performance, unless expressed as such, and should only be viewed as historical data.

        You should also read carefully the factors described in the "Risk Factors" section of this prospectus and elsewhere to better understand the risks and uncertainties inherent in our business and underlying any forward-looking statements. As a result of these factors, we cannot assure you that the forward-looking statements in this prospectus will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified timeframe, or at all. The Private Securities Litigation Reform Act of 1995 and Section 27A of the Securities Act do not protect any forward-looking statements that we make in connection with the offering of Leap common stock in the merger.

        We obtained the industry, market and competitive position data in this prospectus from our own internal estimates and research as well as from industry and general publications and research surveys and studies conducted by third parties. Industry publications and surveys generally state that the information contained therein has been obtained from sources believed to be reliable. We believe this data is accurate in all material respects as of the date of this prospectus.

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RISK FACTORS

        By voting in favor of the merger proposal, Macrocure shareholders will be choosing to invest in Leap common stock following the consummation of the merger. An investment in Leap common stock involves a high degree of risk. Before you vote, you should carefully consider the risks described below, those described in the section entitled "Cautionary Statement Regarding Forward-Looking Statements" beginning on Page 22 of this prospectus and the other information contained in this prospectus. See the section entitled "Where You Can Find More Information" beginning on Page 260 of this prospectus. In addition to the risks set forth below, new risks may emerge from time to time and it is not possible to predict all risk factors, nor can Leap or Macrocure assess the impact of all factors on the merger and the combined company following the merger or the extent to which any factor or combination of factors may cause actual results to differ materially from those contained in or implied by any forward-looking statements. References to "we," "us," "our" and other first person declarations in these risk factors refer to the operations of the combined company following the completion of the merger. Where this prospectus uses the words describing either Macrocure or Leap, as the case may be, it is referring to such entity as a standalone company or to their respective lines of business and industry as they relate to the combined company.

Risks Relating to the Proposed Merger

The amount of merger consideration is dependent on the amount of net cash of Macrocure as of the closing.

        Subject to the terms of the merger agreement, the percentage of the combined company that Macrocure shareholders will own as of the closing of the merger is subject to adjustment at the closing based on the level of Macrocure' net cash prior to the closing. The level of net cash as of that date will be reduced by specified liabilities, as defined further in the merger agreement. On a pro forma basis, but without giving effect to (i) a contemplated $10.0 million equity investment into Leap committed by certain affiliates of Leap immediately prior to the consummation of the merger and (ii) the adoption of Leap's 2016 Equity Incentive Plan, based upon the number of shares of Leap common stock to be issued in the merger (including in respect of outstanding Macrocure options and warrants), Macrocure equityholders (including holders of outstanding Macrocure options and warrants, other than the holders of the out-of-the-money options) will own approximately 35% of Leap and Leap equityholders will own approximately 65% of Leap if Macrocure' net cash as of the closing of the merger is equal to or greater than $22 million. We cannot assure you that any actions taken by Macrocure to attempt to maintain its current level of net cash between now and closing will be successful. In the event that Macrocure's net cash falls below $22.0 million, the percentage ownership of the current Macrocure equityholders (including holders of outstanding Macrocure options and warrants) will decrease relative to the current Leap equityholders. In the event that Macrocure's net cash is below $20.0 million, based on a condition set forth in the merger agreement, Leap is not obligated to consummate the merger.

Ownership of the combined company's common stock will be highly concentrated after consummation of the merger.

        After consummation of the merger and the transactions contemplated by the merger agreement, a limited number of Leap stockholders will have beneficial ownership of significant blocks of outstanding common stock of Leap. Investment funds affiliated with HealthCare Ventures and Eli Lilly and Company ("Lilly") will own or control approximately        % and        %, respectively, of the outstanding shares of common stock of Leap, on a fully-diluted basis after the merger based upon an assumed Macrocure net cash balance equal to or greater than $22.0 million on the closing date. These stockholders, acting individually or as a group, will have substantial influence over the outcome of a corporate action requiring stockholder approval, including the election of directors, any approval of a merger, consolidation or sale of all or substantially all of Leap's assets or any other significant corporate transaction, even if the outcome sought by such stockholders is not in the interest of Leap's

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other stockholders. These stockholders, acting as a group, may also delay or prevent a change in control, even if such change in control would benefit Leap's other stockholders. In addition, the significant concentration of stock ownership may adversely affect the value of Leap common stock due to a resulting lack of liquidity of Leap common stock or a perception among investors that conflicts of interest may exist or arise. In addition, the three executive officers of Leap after the merger—Christopher Mirabelli, Augustine Lawlor and Douglas Onsi—are affiliated with HealthCare Ventures.

The market price of Leap common stock after the merger may be affected by factors different from those currently affecting the financial condition, results of operations and business of Macrocure.

        The business of Leap differs from the Macrocure business in important respects and, accordingly, the results of operations and the market price of Leap common stock following the merger may be significantly different from those currently affecting the independent results of operations of Macrocure. For a discussion of the businesses of Leap and Macrocure and of certain factors to consider in connection with those businesses, see the sections entitled "Business of Leap", "Information About Macrocure" as well as the risks described elsewhere in "Risk Factors" and throughout this prospectus.

The termination fee and restrictions on solicitation contained in the merger agreement may discourage other companies from trying to acquire Leap or Macrocure.

        Until the effective time of the merger, with certain exceptions, the merger agreement prohibits both Leap and Macrocure from entering into or soliciting any acquisition proposal or offer for a merger or other business combination with any other party. The merger agreement provides each of Leap and Macrocure with specified termination rights. If the merger agreement is terminated by Macrocure to accept a superior acquisition proposal or under other circumstances specified in the merger agreement, Macrocure will be required to pay to Leap a termination fee of $1.2 million or $1.6 million, depending on the reason for such termination, plus, in certain circumstances, up to $750,000 of Leap's expenses associated with the merger. These provisions could discourage other companies from trying to acquire Macrocure unless those other companies are willing to offer significantly greater value. Leap has no corresponding right to terminate the merger agreement with respect to a superior acquisition proposal for Leap.

Failure to consummate the merger could adversely affect Leap's and Macrocure's future prospects.

        The merger is subject to the satisfaction of various closing conditions, and neither Leap nor Macrocure can guarantee that the merger will be successfully consummated. In the event that the merger is not consummated for any reason, Leap and Macrocure will be subject to many risks, including the costs related to the merger, such as legal, accounting and advisory fees, which must be paid even if the merger is not consummated, and, potentially, the payment of a termination fee by Macrocure under certain circumstances. If the merger is not consummated, the market price of Macrocure ordinary shares could decline. Leap and Macrocure also could be subject to litigation related to any failure to consummate the merger or related to any enforcement proceeding commenced against Leap or Macrocure to perform their respective obligations under the merger agreement. Finally, if the merger agreement is terminated, Leap or Macrocure may be unable to find another party willing to engage in a similar transaction on terms as favorable as those set forth in the merger agreement, or at all. In particular, the negative publicity that could accompany such a termination could adversely impact Macrocure's ability to find an alternate partner for a strategic transaction or to obtain required financing for any such transaction. This could limit each company's ability to pursue its strategic goals in the event the merger is not consummated.

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The rights of holders of Macrocure ordinary shares will change as a result of the merger.

        After the merger, the rights of those shareholders of Macrocure who will become Leap stockholders will be governed by Leap's amended and restated certificate of incorporation and Leap's amended and restated bylaws, which we refer to as the New Leap Charter and New Leap Bylaws. The New Charter and the New Bylaws will be governed by the laws of the State of Delaware, which may be different from the laws of the State of Israel. Because only shares of Leap common stock will be issued to Macrocure holders of ordinary shares in connection with the merger, persons receiving such shares will not be entitled to any greater rights and preferences than are all other stockholders of Leap. As a result of becoming stockholders of Leap in the merger, the rights of former Macrocure shareholders will be governed by the laws of the State of Delaware, the New Leap Charter and the New Leap Bylaws. For more information, see the section entitled "Comparison of Rights of Leap Stockholders and Macrocure Shareholders" beginning on page 243 of this prospectus.

Some of Macrocure's directors and officers may have interests that are different from yours which may influence them to support or approve the merger and the issuance of shares of Leap common stock in the merger.

        Certain officers and directors of Macrocure participate in arrangements that provide them with interests in the merger that are different from those of other Macrocure shareholders, including in some cases, their continued service as a director of the combined company, severance benefits under the terms of their existing employment agreements (in the case of certain Macrocure officers), acceleration of vesting or preferential treatment with respect to equity awards held by executive officers and continued indemnification of directors and officers. These interests, among others, may influence the officers and directors of Macrocure to support or approve the merger and the issuance of shares of Leap common stock in the merger.

The lack of a public market for Leap common stock makes it more difficult to evaluate the fairness of the merger.

        The outstanding common stock of Leap is privately held and is not traded in any public market. The lack of a public market makes it more difficult to determine the fair value of Leap. Because the percentage of Leap equity to be issued to Macrocure equityholders was determined based on negotiations between the parties to the merger agreement, it is possible that the value of the Leap shares to be issued to Macrocure shareholders in connection with the merger will be greater than the fair value of Macrocure. Alternatively, it is possible that the value of the Leap shares to be issued in connection with the merger will be less than the fair value of Macrocure.

The historical audited and unaudited pro forma condensed combined financial information may not be representative of our results after the merger.

        The historical audited and unaudited pro forma condensed combined financial information included elsewhere in this prospectus has been presented for informational purposes only and is not necessarily indicative of the financial position or results of operations that actually would have occurred had the merger been completed as of the date indicated, nor is it indicative of future operating results or financial position.

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Risks Relating to Business of Leap and Ownership of Leap Common Stock following the Merger

Risks Related to Leap's Financial Position and Capital Needs

We have incurred significant losses since our inception and anticipate that we will continue to incur losses in the future.

        We are a clinical-stage biopharmaceutical company. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that our two product candidates, DKN-01 and TRX518, or any other products will fail to gain regulatory approval or become commercially viable. We have only two clinical-stage product candidates, which are at the early stages of clinical development. We do not have any products approved by regulatory authorities for marketing and have not generated any revenue from product sales. We incur significant research, development and other expenses related to our ongoing operations. As a result, we are not profitable and have incurred losses in every reporting period since our inception in 2011. For the year ended December 31, 2015 and the six months ended June 30, 2016, we reported a net loss of $12.1 million and $12.6 million, respectively, and had an accumulated deficit of $85.3 million at June 30, 2016.

        We expect to continue to incur significant expenses and operating losses for the foreseeable future. We anticipate these losses to increase as we continue the research and development of, and seek regulatory approvals for DKN-01 and TRX518, and we potentially begin to commercialize DKN-01 and TRX518, if they receive regulatory approval. We may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenues. If either or both of DKN-01 or TRX518 fails in clinical trials or does not gain regulatory approval, or if approved, fails to achieve market acceptance, we may never become profitable. Even if we achieve profitability in the future, we may not be able to sustain profitability in subsequent periods.

We currently have no source of product revenue and may never become profitable.

        We have not generated any revenues, and we have no commercial products. Our ability to generate revenue from product sales and achieve profitability will depend upon our ability to successfully gain regulatory approval and commercialize DKN-01 or TRX518 or other product candidates that we may in-license or acquire in the future. Even if we are able to successfully achieve regulatory approval, we do not know when we will generate revenue from product sales, if at all. Our ability to generate revenue from product sales from any product candidates also depends on a number of additional factors, including our ability to:

    successfully complete development activities, including enrollment of study participants and completion of the necessary clinical trials;

    complete and submit new drug applications, or NDAs, or biologics license applications, or BLAs, to the FDA and obtain regulatory approval for indications for which there is a commercial market;

    complete and submit applications to, and obtain regulatory approval from, foreign regulatory authorities;

    make or have made commercial quantities of our products at acceptable cost levels;

    develop a commercial organization capable of manufacturing, sales, marketing and distribution for any products we intend to sell ourselves in the markets in which we choose to commercialize on our own;

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    find suitable partners to help us market, sell and distribute our approved products in other markets; and

    obtain adequate pricing, coverage and reimbursement from third parties, including government and private payors.

        In addition, because of the numerous risks and uncertainties associated with product development, including that DKN-01 or TRX518 may not advance through development or achieve the endpoints of applicable clinical trials, we are unable to predict the timing or amount of increased expenses, or when or if we will be able to achieve or maintain profitability. Even if we are able to complete the development and regulatory process for DKN-01 and/or TRX518, we anticipate incurring significant costs associated with commercializing these products, including in building the requisite sales and marketing capabilities to sell such products (which itself may pose financial and operational risks).

        Even if we are able to generate revenues from the sale of our products, we may not become profitable and will need to obtain additional funding to continue operations. If we fail to become profitable or are unable to sustain profitability on a continuing basis, and we are not successful in obtaining additional funding, then we may be unable to continue our operations at planned levels.

We will require additional capital to fund our operations and if we fail to obtain necessary financing, we may be unable to complete the development and potential commercialization of DKN-01 or TRX518 or acquire other products.

        Our operations have consumed substantial amounts of cash since inception. We expect to continue to spend substantial amounts to advance the clinical development of DKN-01 and TRX518 and launch and commercialize these product candidates, if we receive regulatory approval. We will require additional capital for the further development and potential commercialization. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or any future commercialization efforts.

        We believe that our cash and cash equivalents immediately following the merger will enable us to fund our operating expenses and capital expenditure requirements for at least the next 15 months. We have based this estimate on assumptions that may prove to be wrong, and we could deploy our available capital resources sooner than we currently expect. Our future funding requirements, both near and long-term, will depend on many factors, including, but not limited to the:

    initiation, progress, timing, costs and results of pre-clinical studies and clinical trials for our product candidates;

    costs and timing of additional clinical trial and commercial manufacturing activities;

    clinical development plans we establish for DKN-01, TRX518, and any other future product candidates;

    number and characteristics of any new product candidates that we in-license and develop;

    outcome, timing and cost of regulatory review by the FDA and comparable foreign regulatory authorities, including the potential for the FDA or comparable foreign regulatory authorities to require that we perform more studies than those that we currently expect;

    costs of filing, prosecuting, defending and enforcing any patent claims and maintaining and enforcing other intellectual property rights;

    effect of competing product candidates and market developments; and

    costs and timing of establishing sales, marketing and distribution capabilities for any product candidates for which we may receive regulatory approval.

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        If we are unable to fund our operations or otherwise capitalize on our business opportunities due to a lack of capital, our ability to become profitable will be compromised.

Raising additional capital may cause dilution to our existing stockholders, restrict our operations or require us to relinquish rights to our product candidates.

        Until we can generate substantial revenue from product sales, if ever, we expect to seek additional capital through a combination of private and public equity offerings, debt financings, strategic collaborations and alliances and licensing arrangements. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interests of existing stockholders will be diluted, and the terms may include liquidation or other preferences that adversely affect the rights of existing stockholders. Debt financing, if available, may involve agreements that include liens or other restrictive covenants limiting our ability to take important actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we are unable to raise additional funds through equity or debt financing when needed, we may be required to delay, limit, reduce or terminate our product development or commercialization efforts or grant rights to develop and market our product candidates that we would otherwise prefer to develop and market ourselves. If we raise additional funds through strategic collaborations and alliances or licensing arrangements with third parties, we may have to relinquish valuable rights to our product candidates in particular countries, or grant licenses on terms that are not favorable to us.

Risks Related to Our Business and Industry

Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process.

        The results of preclinical studies, preliminary study results, and early clinical trials of our product candidates may not be predictive of the results of later-stage clinical trials or the ultimately completed trial. For instance, while we have preliminary study results for our clinical studies of DKN-01 in esophageal cancer and cholangiocarcinoma, as well as our two clinical studies of TRX518, these studies are still ongoing and the ultimate study results may be different than the preliminary ones we have seen to date. Moreover, while we have seen preliminary favorable results in individual study subjects, these results may not be representative of the ultimate study population. Finally, the clinical trials conducted to date for DKN-01 and TRX518 are relatively small, open-label, uncontrolled studies. Preliminary and final results from such studies may not be representative of study results that are found in larger, controlled, blinded, and more long term studies.

        Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy traits despite having progressed through preclinical studies and initial clinical trials. Preclinical studies may also reveal unfavorable product candidate characteristics, including safety concerns. In some instances, there can be significant variability in safety or efficacy results between different clinical trials of the same product candidate due to numerous factors, including changes in trial procedures set forth in protocols, the impact of an active comparator arm, differences in the size and type of the patient populations, changes in and adherence to the clinical trial protocols, changes in medical prescribing practices and the rate of dropout among clinical trial participants.

        Our future clinical trial results may not be successful. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials, notwithstanding promising results in earlier trials. Moreover, should there be a flaw in a clinical trial, it may not become apparent until the clinical trial is well advanced. Further, because we currently plan to develop our product candidates for use with established oncology products, the design, implementation, and interpretation of the clinical trials necessary for marketing approval may be more complex than if we were developing our product candidates alone.

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        We may also experience numerous unforeseen events during, or as a result of, clinical trials that could delay or adversely affect our existing or future development programs, including:

    we may have delays in identifying and adding new investigators or clinical trial sites, we may experience delays in reaching, or fail to reach, agreement on acceptable clinical trial contracts or clinical trial protocols with prospective trial sites and our CROs or we may experience a withdrawal of clinical trial sites;

    the number of patients required for clinical trials of our product candidates may be larger than we anticipate, enrollment in these clinical trials may be slower than we anticipate or participants may drop out of these clinical trials at a higher rate than we anticipate;

    clinical trials of our product candidates may produce negative or inconclusive results, or our studies may fail to reach the necessary level of statistical significance, and we may decide to conduct additional clinical trials or abandon product development programs;

    we may not be able to demonstrate that a product candidate provides an advantage over current standards of care or current or future competitive therapies in development.

    the cost of clinical trials of our product candidates may be greater than we anticipate or we may have insufficient funds for a clinical trial;

    the supply or quality of the clinical trial material of our product candidates may be insufficient or inadequate to conduct clinical trials; and

    there may be changes to the therapeutics or their regulatory status which we are administering in combination with our product candidates or changes to standard of care, which require that we change our study design, or otherwise halt, discontinue or delay our clinical studies. This occurred for a multiple myeloma study that we were conducting. In that case, the standard of care changed such that we were no longer able to recruit study subjects under the study protocol.

The regulatory approval processes of the FDA and comparable foreign authorities are lengthy, time consuming and inherently unpredictable, especially for an early-stage company such as ours. If we are not able to obtain, or if there are delays in obtaining, required regulatory approvals, we will not be able to commercialize our product candidates as expected, and our ability to generate revenue will be materially impaired.

        Because we are at the early stages of the clinical and regulatory development of our product candidates,, the time required to obtain approval for them from the FDA and comparable foreign authorities is unpredictable but typically takes many years following the commencement of clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate's clinical development and may vary among jurisdictions. These may require us to amend our clinical trial protocols, conduct additional studies that require regulatory or institutional review board, or IRB, approval, or otherwise cause delays in the approval or rejection of an application. We have not obtained regulatory approval for any product candidate and it is possible that none of our existing product candidates or any product candidates we may seek to develop in the future, will ever obtain regulatory approval. Moreover, we have only completed early studies and enrolled limited numbers of patients for both DKN-01 and TRX518. Both DKN-01 and TRX518 will require additional preclinical and clinical development, as well as additional manufacturing development before we will be able to submit marketing applications to FDA. Moreover, should FDA determine that a companion diagnostic device is required for use of our product candidates or should we decide to pursue the development of a companion diagnostic device for the use of our product candidates, further development work would be required for such a device, including, possibly the approval of an Investigational Device Exemption for the study of such a

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device from FDA, compliance with FDA's device regulations, and either FDA clearance or approval of the device for commercial use. Such development would potentially take additional time and be subject to the risk of FDA non-approval or clearance of the diagnostic. Any delay in obtaining or failure to obtain required approvals could materially adversely affect our ability or that of any of our future collaborators to generate revenue from the particular product candidate, which likely would result in significant harm to our financial position and adversely impact our stock price.

        Our product candidates and the activities associated with their development and commercialization, including their design, testing, manufacture, safety, efficacy, recordkeeping, labeling, storage, approval, advertising, marketing, promotion, sale, and distribution, are subject to comprehensive regulation by the FDA and other regulatory agencies in the United States and by the EMA, and similar regulatory authorities outside the United States and Europe. Failure to obtain marketing approval for a product candidate will prevent us from commercializing the product candidate. We have no experience in filing and supporting the applications necessary to gain marketing approvals and expect to rely on third-party clinical research organizations, or CROs, and consultants to assist us in this process. Securing marketing approval requires the submission of extensive preclinical and clinical data and supporting information to regulatory authorities for each therapeutic indication to establish the product candidate's safety, purity, and potency for that indication. Securing marketing approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities and clinical trial sites by, the regulatory authorities.

        We may also experience numerous unforeseen events during, or as a result of, clinical trials that could delay or prevent our ability to receive marketing approval or commercialize our product candidates, including:

    regulators or IRBs may not authorize us or our investigators to commence a clinical trial or to conduct a clinical trial at a prospective trial site, we may fail to reach an agreement with regulators or IRBs regarding the scope, design, or implementation of our clinical trials or regulators or IRBs may require that we modify or amend our clinical trial protocols;

    our third-party contractors may fail to comply with regulatory requirements, standard operating procedures or the clinical trial protocol, or meet their contractual obligations to us in a timely manner, or at all, or we may be required to engage in additional clinical trial site monitoring or manufacturing activities;

    we, the regulators, or IRBs may require that we or our investigators suspend or terminate clinical research for various reasons, including noncompliance with regulatory requirements or a finding that the participants are being exposed to unacceptable health risks, undesirable side effects, or other unexpected characteristics of the product candidate, or due to findings of undesirable effects caused by a chemically or mechanistically similar therapeutic or therapeutic candidate;

    changes in or the enactment of additional statutes or regulations;

    there may be changes in marketing approval or regulatory review policies during the development period rendering our data insufficient to obtain marketing approval;

    we may decide, or regulators may require us, to conduct additional clinical trials, analyses, reports, data, or preclinical trials, or we may abandon product development programs;

    there may be regulatory questions or disagreements regarding interpretations of data and results, or new information may emerge regarding our product candidates, the FDA or comparable foreign regulatory authorities may disagree with our study design or our interpretation of data from preclinical studies and clinical trials or find that a product candidate's benefits do not outweigh its safety risks;

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    the FDA or comparable regulatory authorities may disagree with our intended indications;

    the FDA or comparable foreign regulatory authorities may fail to approve or subsequently find fault with the manufacturing processes or our manufacturing facilities for clinical and future commercial supplies;

    the data collected from clinical trials of our product candidates or any additional product candidate may not be sufficient to the satisfaction of the FDA or comparable foreign regulatory authorities to support the submission of a NDA, or other comparable submission in foreign jurisdictions or to obtain regulatory approval in the United States or elsewhere; and

    the FDA or comparable regulatory authorities may take longer than we anticipate to make a decision on our product candidates.

        Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent marketing approval of a product candidate. The number and types of preclinical studies and clinical trials that will be required for regulatory approval also varies depending on the product candidate, the disease or condition that the product candidate is designed to address, and the regulations applicable to any particular product candidate. Approval policies, regulations or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate's clinical development and may vary among jurisdictions, and there may be varying interpretations of data obtained from preclinical studies or clinical trials, either of which may cause delays or limitations in the approval or the decision not to approve an application. It is possible that neither of our product candidates nor any product candidates we may seek to develop in the future will ever obtain the appropriate regulatory approvals necessary for us or any future collaborators to commence product sales.

        Finally, even if we were to obtain approval, regulatory authorities may approve any of our product candidates for fewer or more limited indications or uses than we request, may contain significant safety warnings, including black box warnings, contraindications, and precautions, may grant approval contingent on the performance of costly post-marketing clinical trials, surveillance, or other requirements, including risk evaluation and mitigation strategies, or REMS, to monitor the safety or efficacy of the product, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate. Any of these scenarios could compromise the commercial prospects for our product candidates.

        If we experience delays in obtaining approval, if we fail to obtain approval of a product candidate or if the label for a product candidate does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate, the commercial prospects for such product candidate may be harmed and our ability to generate revenues from that product candidate will be materially impaired.

If we experience delays or difficulties in the enrollment of patients in clinical trials, our receipt of necessary regulatory approvals could be delayed or prevented.

        We may not be able to initiate or continue conducting clinical trials for our product candidates if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside the United States. Some of our competitors have ongoing clinical trials for product candidates that treat the same indications or use the same mechanism of action as our product candidates, and patients who would otherwise be eligible

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for our clinical trials may instead enroll in clinical trials of our competitors' product candidates. Patient enrollment is affected by other factors including:

    the size and nature of the patient population;

    the severity of the disease under investigation;

    the eligibility criteria for, and design of, the clinical trial in question, including factors such as frequency of required assessments, length of the study and ongoing monitoring requirements;

    the perceived risks and benefits of the product candidate under study, including the potential advantages or disadvantages of the product candidate being studied in relation to other available therapies;

    competition in recruiting and enrolling patients in clinical trials;

    the efforts to facilitate timely enrollment in clinical trials;

    the patient referral practices of physicians;

    effectiveness of publicity created by clinical trial sites regarding the trial;

    patients' ability to comply with the specific instructions related to the trial protocol, proper documentation, and use of the biologic product;

    our inability to obtain or maintain patient informed consents;

    the risk that enrolled patients will drop out before completion or not return for post-treatment follow-up;

    the ability to monitor patients adequately during and after treatment; and

    the proximity and availability of clinical trial sites for prospective patients.

        Our inability to enroll a sufficient number of patients for our clinical trials would result in significant delays and could require us to abandon one or more clinical trials altogether.

        Enrollment delays in our clinical trials may result in increased development costs for our product candidates, or the inability to complete development of our product candidates, which would materially impair our ability to generate revenues, limit our ability to obtain additional financing and cause the value of our company to decline.

The FDA may determine that any of our current or future product candidates have undesirable side effects that could delay or prevent their regulatory approval or commercialization.

        Undesirable side effects caused by our product candidates could cause us, IRBs, and other reviewing entities or regulatory authorities to interrupt, delay, or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other comparable foreign authorities. For example, if concerns are raised regarding the safety of a new therapeutic as a result of undesirable side effects identified during clinical or preclinical testing, the FDA may order us to cease further development, decline to approve a product candidate or issue a letter requesting additional data or information prior to making a final decision regarding whether or not to approve the biologic. FDA requests for additional data or information can result in substantial delays in the approval of a new biologic.

        Undesirable side effects caused by any of our current or future product candidates could also result in denial of regulatory approval by the FDA or other comparable foreign authorities for any or all targeted indications or the inclusion of unfavorable information in our product labeling, such as limitations on the indicated uses for which the products may be marketed or distributed, a label with

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significant safety warnings, including boxed warnings, contraindications, and precautions, a label without statements necessary or desirable for successful commercialization, or may result in requirements for costly post-marketing testing and surveillance, or other requirements, including REMS, to monitor the safety or efficacy of the products, and in turn prevent us from commercializing and generating revenues from the sale of our current or future product candidates.

        If any of our product candidates is associated with serious adverse events or undesirable side effects or have properties that are unexpected, we may need to abandon development or limit development of that product candidate to certain uses or subpopulations in which the undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective. The therapeutic-related side effects could affect patient recruitment or the ability of enrolled patients to complete the trial or result in potential product liability claims. Any of these occurrences may significantly harm our business, financial condition, results of operations, and prospects.

Failure to obtain marketing approval in international jurisdictions would prevent our product candidates from being marketed abroad.

        In order to market and sell our products in the European Union and other jurisdictions, we or our third-party collaborators must obtain separate marketing approvals and comply with numerous and varying regulatory requirements. The approval procedure varies among countries and can involve additional testing, in some cases involving clinical trials involving subjects from the country. The time required to obtain approval may differ substantially from that required to obtain FDA approval. The regulatory approval process outside the United States generally includes all of the risks associated with obtaining FDA approval. In addition, in many countries outside the United States, it is required that the product be approved for reimbursement before the product can be approved for sale in that country. We or these third parties may not obtain approvals from regulatory authorities outside the United States on a timely basis, if at all. Approval by the FDA does not ensure approval by regulatory authorities in other countries or jurisdictions, and approval by one regulatory authority outside the United States does not ensure approval by regulatory authorities in other countries or jurisdictions or by the FDA. However, the failure to obtain approval in one jurisdiction may compromise our ability to obtain approval elsewhere. We may not be able to file for marketing approvals and may not receive necessary approvals to commercialize our products in any market.

Even if our product candidates receive regulatory approval, we will be subject to ongoing obligations and continued regulatory review, which may result in significant additional expense. Additionally, any of our product candidates, if approved, could be subject to labeling and other restrictions and market withdrawal and we may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our products.

        Any product candidate for which we obtain marketing approval will be subject to extensive and ongoing requirements of and review by the FDA and other regulatory authorities, including requirements related to the manufacturing processes, post-approval clinical data, labeling, packaging, distribution, adverse event reporting, storage, recordkeeping, export, import, advertising, marketing, and promotional activities for such product. These requirements further include submissions of safety and other post-marketing information, including manufacturing deviations and reports, registration and listing requirements, the payment of annual fees for our product candidates, if approved, and the establishments at which they are manufactured, continued compliance with cGMP requirements relating to manufacturing, quality control, quality assurance, and corresponding maintenance of records and documents, requirements regarding the distribution of samples to physicians and recordkeeping, and good clinical practices, or GCPs, for any clinical trials that we conduct post-approval.

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        Even if marketing approval of a product candidate is granted, the approval may be subject to limitations on the indicated uses and populations for which the product may be marketed or to the conditions of approval, including significant safety warnings, including boxed warnings, contraindications, and precautions that are not desirable for successful commercialization and any requirement to implement a REMS that render the approved product not commercially viable or other post-market requirements or restrictions. Moreover, the FDA and comparable foreign regulatory authorities will continue to closely monitor the safety profile of any product even after approval. If the FDA or comparable foreign regulatory authorities become aware of new safety information after approval of any of our product candidates, they may withdraw approval, require labeling changes or establishment of a REMS or similar strategy, impose significant restrictions on a product's indicated uses or marketing, or impose ongoing requirements for potentially costly post-approval studies or post-market surveillance. Any such restrictions could limit sales of the product.

        We and any of our collaborators, including our contract manufacturers, could be subject to periodic unannounced inspections by the FDA to monitor and ensure compliance with cGMPs. Application holders must further notify the FDA, and depending on the nature of the change, obtain FDA pre-approval for product and manufacturing changes. Application fees may apply to certain changes.

        In addition, later discovery of previously unknown adverse events or that the product is less effective than previously thought or other problems with our products, manufacturers or manufacturing processes, or failure to comply with regulatory requirements both before and after approval, may yield various results, including:

    restrictions on manufacturing or distribution, or marketing of such products;

    restrictions on the labeling, including required additional warnings, such as black box warnings, contraindications, precautions, and restrictions on the approved indication or use;

    modifications to promotional pieces;

    requirements to conduct post-marketing studies or clinical trials;

    clinical holds or termination of clinical trials;

    requirements to establish or modify a REMS or a comparable foreign authority may require that we establish or modify a similar strategy, that may, for instance, require us to create a Medication Guide outlining the risks of the previously unidentified side effects for distribution to patients, or restrict distribution of the product, if and when approved, and impose burdensome implementation requirements on us;

    changes to the way the biologic is administered;

    liability for harm caused to patients or subjects;

    reputational harm;

    the product becoming less competitive;

    warning, untitled, or cyber letters;

    suspension of marketing or withdrawal of the products from the market;

    regulatory authority issuance of safety alerts, Dear Healthcare Provider letters, press releases, or other communications containing warnings or other safety information about the biologic;

    refusal to approve pending applications or supplements to approved applications that we submit;

    recalls of products;

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    fines, restitution or disgorgement of profits or revenues;

    suspension or withdrawal of marketing approvals;

    refusal to permit the import or export of our products;

    product seizure or detention;

    FDA debarment, debarment from government contracts, and refusal of future orders under existing contracts, exclusion from federal healthcare programs, consent decrees, or corporate integrity agreements; or

    injunctions or the imposition of civil or criminal penalties, including imprisonment.

        Any of these events could prevent us from achieving or maintaining market acceptance of the particular product candidate, if approved, or could substantially increase the costs and expenses of commercializing such product, which in turn could delay or prevent us from generating significant revenues from its sale. Any of these events could further have other material and adverse effects on our operations and business and could adversely impact our stock price and could significantly harm our business, financial condition, results of operations, and prospects.

Laws, regulatory policies, and medical practices could change in ways that are not favorable to us.

        The FDA's policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates, that could limit the marketability of our product candidates, or that could impose additional regulatory obligations on us if our product candidates are approved. Changes in medical practice and standard of care may also impact the marketability of our product candidates. For instance, because we are currently planning to develop our product candidates for use with other cancer therapies, should there be a change to the regulatory status of the other therapy or should the standard of care change, the marketability of our product candidates would be impacted.

        If we are slow or unable to adapt to changes in existing requirements, standards of care, or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and be subject to regulatory enforcement action.

        Should any of the above actions take place, they could adversely affect our ability to achieve or sustain profitability. Further, the cost of compliance with post-approval regulations may have a negative effect on our operating results and financial condition.

Risks Related to the Development and Commercialization of Our Product Candidates

The therapeutic safety and efficacy of DKN-01 and TRX518 is unproven, and we may not be able to successfully develop and commercialize DKN-01 or TRX518.

        DKN-01 and TRX518 are novel monoclonal antibodies and their potential benefit as a therapeutic cancer drug is unproven. Our ability to generate revenues from the sales of our products, which we do not expect will occur in the short term, if ever, will depend on successful development and commercialization after approval, if achieved, which is subject to many potential risks. DKN-01 or TRX518 may interact with human biological systems in unforeseen, ineffective or harmful ways. If either DKN-01 or TRX518 is associated with undesirable side effects or has characteristics that are unexpected, we may need to abandon its development or limit development to certain uses or subpopulations in which the undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective. Many compounds that initially showed promise in early stage testing for treating cancer have later been found to be ineffective in later stage

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studies or cause side effects that prevented further development of the compound. As a result of these and other risks described herein that are inherent in the development of novel therapeutic agents, we may never successfully develop, enter into or maintain third party licensing or collaboration transactions with respect to, or successfully commercialize DKN-01 or TRX518, in which case we will not achieve profitability and the value of our stock may decline.

The results of pre-clinical studies or early clinical trials are not necessarily predictive of future results, and DKN-01 or TRX518 may not have favorable results in later clinical trials or receive regulatory approval.

        Success in pre-clinical studies and early clinical trials does not ensure that later clinical trials will generate adequate data to demonstrate the efficacy and safety of DKN-01 or TRX518. A number of companies in the pharmaceutical and biotechnology industries, including those with greater resources and experience than we have, have suffered significant setbacks in clinical trials, even after seeing promising results in earlier clinical trials. Despite the results reported in earlier preclinical and clinical trials for DKN-01 and TRX518, we do not know whether the clinical trials we may conduct will demonstrate adequate efficacy and safety to result in regulatory approval to market DKN-01 or TRX518 in any particular jurisdiction. If our clinical trials do not produce favorable results, our ability to achieve regulatory approval for DKN-01 or TRX518 will be adversely impacted and the value of our stock may decline.

Our future success is dependent primarily on the regulatory approval and commercialization of DKN-01 and TRX518, which are currently undergoing early stage clinical trials.

        We do not have any products that have gained regulatory approval. Currently, our only clinical-stage product candidates are DKN-01 and TRX518. As a result, our business is substantially dependent on our ability to obtain regulatory approval for, and, if approved, to successfully commercialize DKN-01 or TRX518 or other products in a timely manner. We cannot commercialize these products in the U.S. without first obtaining regulatory approval from the FDA; similarly, we cannot commercialize these products outside of the U.S. without obtaining regulatory approval from comparable foreign regulatory authorities. Before obtaining regulatory approvals for the commercial sale of these products for a target indication, we must demonstrate with substantial evidence gathered in pre-clinical studies and well-controlled clinical trials, that these products are safe and effective for use for that target indication and that the manufacturing facilities, processes and controls are adequate. Even if these products were to successfully obtain approval from the FDA and comparable foreign regulatory authorities, any approval might contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, or may be subject to burdensome post-approval study or risk management requirements. If we are unable to obtain regulatory approval in one or more jurisdictions, or any approval contains significant limitations, we may not be able to obtain sufficient funding or generate sufficient revenue to continue the development of any other product candidate that we may discover, in-license, develop or acquire in the future. Furthermore, even if we obtain regulatory approval for our products, we will still need to develop a commercial organization or strategy, establish commercially viable pricing and obtain approval for adequate reimbursement from third-party and government payors. If we are unable to successfully commercialize our products, we may not be able to earn sufficient revenues to continue our business.

Our commercial success depends upon attaining significant market acceptance of DKN-01 or TRX518, if approved, among physicians, patients, healthcare payors and the major operators of cancer clinics.

        Even if we obtain regulatory approval for DKN-01 or TRX518, DKN-01 or TRX518 may not gain market acceptance among physicians, healthcare payors, patients or the medical community. Market

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acceptance of DKN-01 or TXR518, if we receive approval, depends on a number of factors, including the:

    efficacy and safety of DKN-01 or TRX518 each as demonstrated in clinical trials and post-marketing experience;

    clinical indications for which DKN-01 or TRX518 is approved;

    acceptance by physicians, major operators of cancer clinics and patients of DKN-01 or TRX518 as a safe and effective treatment;

    potential and perceived advantages of DKN-01 or TRX518 over alternative treatments;

    product labeling or product insert requirements of the FDA or other regulatory authorities;

    timing of market introduction of DKN-01 or TRX518 as well as competitive products;

    cost of treatment in relation to alternative treatments;

    availability of coverage and adequate reimbursement and pricing by third-party payors and government authorities;

    relative convenience and ease of administration; and

    effectiveness of our sales and marketing efforts.

        Moreover, if DKN-01 or TRX518 is approved but fails to achieve market acceptance among physicians, patients, or healthcare payors, we may not be able to generate significant revenues, which would compromise our ability to become profitable.

If we are unable to establish effective marketing and sales, capabilities or enter into agreements with third parties to market and sell our product candidates, if they are approved, we may be unable to generate product revenues.

        We currently do not have a commercial infrastructure for the marketing, sale, and distribution of pharmaceutical products. If approved, in order to commercialize our products, we must build our marketing, sales, and distribution capabilities or make arrangements with third parties to perform these services. We may not be successful in doing so. Should we decide to develop our own marketing capabilities, we will incur substantial expenses prior to product launch or even approval in order to recruit a sales force and develop a marketing and sales infrastructure. If a commercial launch is delayed as a result of FDA requirements or other reasons, we would incur these expenses prior to being able to realize any revenue from sales of our product candidates. Even if we are able to effectively hire a sales force and develop a marketing and sales infrastructure, our sales force and marketing teams may not be successful in commercializing our current or future product candidates.

        We have no prior experience in the marketing, sale, and distribution of pharmaceutical products, and there are significant risks involved in the building and managing of a commercial infrastructure. The establishment and development of commercial capabilities, including compliance plans, to market any products we may develop will be expensive and time consuming and could delay any product launch, and we may not be able to successfully develop this capability. We, or our future collaborators, will have to compete with other pharmaceutical and biotechnology companies to recruit, hire, train, manage, and retain marketing and sales personnel.

        We may also or alternatively decide to collaborate with a third-party marketing and sales organization to commercialize any approved product candidates, in which event, our ability to generate product revenue may be reduced. To the extent we rely on third parties to commercialize any products for which we obtain regulatory approval, we may receive less revenue than if we commercialized these products ourselves. In addition, we would have less control over the sales efforts of any other third

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parties involved in our commercialization efforts, and could be held liable if they failed to comply with applicable legal or regulatory requirements.

Even if we are able to commercialize DKN-01 or TRX518, DKN-01 or TRX518 may not receive coverage and adequate reimbursement from third-party payors, which could harm our business.

        Our ability to commercialize DKN-01 or TRX518 successfully will depend, in part, on the extent to which coverage and adequate reimbursement for DKN-01 or TRX518 and related treatments will be available from government health administration authorities, private health insurers and other organizations. Government authorities and third-party payors, such as private health insurers and health maintenance organizations, determine which medications they will cover and establish reimbursement levels. We cannot be sure that coverage and adequate reimbursement will be available for DKN-01 or TRX518 and, if reimbursement is available, what the level of reimbursement will be. Coverage and reimbursement may impact the demand for, or the price of, DKN-01 or TRX518, if we obtain marketing approval. If reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize DKN-01 or TRX518, if we obtain marketing approval.

        There may be significant delays in obtaining coverage and reimbursement for newly approved drugs, and coverage may be more limited than the purposes for which the drug is approved by the FDA or comparable foreign regulatory authorities. Moreover, eligibility for coverage and reimbursement does not imply that any drug will be paid for in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement policies. Our inability to obtain coverage and profitable reimbursement rates from both government-funded and private payors for any approved products that we develop could have a material adverse effect on our operating results, our ability to raise capital needed to commercialize products and our overall financial condition.

We face substantial competition, which may result in others discovering, developing or commercializing products before, or more successfully than, we do.

        The development and commercialization of new drug products is highly competitive, especially in the oncology space in which we operate. We face competition with respect to DKN-01 and TRX518, and will face competition with respect to any other product candidates that we may seek to develop or commercialize in the future, from major pharmaceutical companies, specialty pharmaceutical companies and biotechnology companies worldwide. There are a number of large pharmaceutical and biotechnology companies that currently market and sell products or are pursuing the development of products for the treatment of cancer. Some of these competitive products and therapies are based on scientific approaches that are the same as or similar to our approach for DKN-01 or TRX518, and others are based on entirely different approaches. For example, there are several companies developing product candidates that target the same cancer pathways that we are targeting or that are testing product candidates in the same cancer indications that we are testing. For example, Novartis AG, or Novartis, Merck & Co., or Merck, and Pfizer, Inc. are all currently developing or have previously been developing anti-DKK1 monoclonal antibodies. Additionally, Merck, Novartis, Bristol-Myers Squibb Company, AstraZeneca PLC and Agenus Inc., in partnership with Incyte Corporation, are developing a GITR agonist monoclonal antibody.

        More established companies may have a competitive advantage over us due to their greater size, cash flows and institutional experience. Compared to us, many of our competitors may have significantly greater financial, technical and human resources. As a result of these factors, our competitors may obtain regulatory approval of their products before we are able to, which may limit our ability to develop or commercialize DKN-01 or TRX518. Our competitors may also develop drugs that are safer, more effective, more widely used and cheaper than ours, and may also be more

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successful than us in manufacturing and marketing their products. These appreciable advantages could render DKN-01 or TRX518 non-competitive before we can recover the expenses of development and commercialization.

Our product candidates may face biosimilar competition sooner than anticipated.

        The enactment of the Biologics Price Competition and Innovation Act of 2009, or BPCIA, as part of the Affordable Care Act, or ACA, created an abbreviated pathway for the approval of biosimilar and interchangeable biological products. The abbreviated regulatory pathway establishes legal authority for the FDA to review and approve biosimilar biologics, including the possible designation of a biosimilar as "interchangeable" based on its similarity to an existing brand product. Under the BPCIA, an application for a biosimilar product cannot be approved by the FDA until 12 years after the original branded product was approved under a BLA.

        We believe our product candidates approved as a biological product under a BLA, should qualify for the BPCIA's 12-year period of exclusivity. However, this period of regulatory exclusivity does not apply to companies pursuing regulatory approval via their own traditional BLA, rather than via the abbreviated pathway. Moreover, the extent to which a biosimilar, once approved, will be substituted for any one of our reference products in a way that is similar to traditional generic substitution for non-biological products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing.

        The law is complex and is still being interpreted and implemented by the FDA. As a result, its ultimate impact, implementation, and meaning are subject to uncertainty. While it is uncertain when such processes intended to implement the BPCIA may be fully adopted by the FDA, any such processes could have a material adverse effect on the future commercial prospects for our biological products. Future proposed budgets, international trade agreements and other arrangements or proposals may also affect periods of exclusivity in the future.

We face potential product liability exposure, and if successful claims are brought against us, we may incur substantial liability for our current or future product candidates and may have to limit their commercialization.

        The use of our current or future product candidates in clinical trials, and the sale of any of our product candidates for which we obtain regulatory approval, exposes us to the risk of product liability claims. We face inherent risk of product liability related to the testing of our product candidates in human clinical trials and will face an even greater risk if we commercially sell any product candidates that we may develop. Product liability claims might be brought against us by consumers, healthcare providers or others using, administering or selling our products. If we cannot successfully defend ourselves against these claims, we will incur substantial liabilities or be required to limit commercialization of our product candidates. Even successful defense would require significant financial and management resources.

        While we currently carry insurance that we believe is appropriate for a company at our stage of development, our insurance coverage may not reimburse us or may not be sufficient to reimburse us for any expenses or losses we may suffer. Moreover, insurance coverage is becoming increasingly expensive, and, in the future, we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to liability. On occasion, large judgments have been awarded in class action lawsuits based on therapeutics that had unanticipated side effects. A successful product liability claim or series of claims brought against us could cause our stock price to fall and, if judgments exceed our insurance coverage, could decrease our cash and adversely affect our business and our prospects.

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Laws and regulations governing international operations may preclude us from developing, manufacturing and selling product candidates outside of the U.S. and require us to develop and implement costly compliance programs.

        As we seek to expand our operations outside of the U.S., we must comply with numerous laws and regulations in each jurisdiction in which we plan to operate. The creation and implementation of international business practices compliance programs is costly and such programs are difficult to enforce, particularly where reliance on third parties is required.

        The Foreign Corrupt Practices Act, or FCPA, prohibits any U.S. individual or business from paying, offering, authorizing payment or offering of anything of value, directly or indirectly, to any foreign official, political party or candidate for the purpose of influencing any act or decision of the foreign entity in order to assist the individual or business in obtaining or retaining business. The FCPA also obligates companies whose securities are listed in the U.S. to comply with certain accounting provisions requiring such companies to maintain books and records that accurately and fairly reflect all transactions of the corporation, including international subsidiaries, and to devise and maintain an adequate system of internal accounting controls for international operations. The anti-bribery provisions of the FCPA are enforced primarily by the Department of Justice, or DOJ. The Securities and Exchange Commission, or the Commission, is involved with enforcement of the books and records provisions of the FCPA.

        Compliance with the FCPA is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, the FCPA presents particular challenges in the pharmaceutical industry, because, in many countries, hospitals are operated by the government, and doctors and other hospital employees are considered foreign officials. Certain payments to hospitals in connection with clinical trials and other work have been deemed to be improper payments to government officials and have led to FCPA enforcement actions.

        Various laws, regulations and executive orders also restrict the use and dissemination outside of the U.S., or the sharing with certain non-U.S. nationals, of information classified for national security purposes, as well as certain products and technical data relating to those products. Our expanding presence outside of the U.S. will require us to dedicate additional resources to comply with these laws, and these laws may preclude us from developing, manufacturing, or selling DKN-01 or TRX518 outside of the U.S., which could increase our development costs and limit our growth potential.

        The failure to comply with laws governing international business practices may result in substantial penalties, including suspension or debarment from government contracting. Violation of the FCPA can result in significant civil and criminal penalties. Indictment alone under the FCPA can lead to suspension of the right to do business with the U.S. government until the pending claims are resolved. Conviction of a violation of the FCPA can result in long-term disqualification as a government contractor. The termination of a government contract or relationship as a result of our failure to satisfy any of our obligations under laws governing international business practices, which would have a negative impact on our business and harm our reputation and ability to procure government contracts. The Commission also may suspend or bar issuers from trading securities on U.S. exchanges for violations of the FCPA's accounting provisions.

Our relationships with customers and third-party payors will be subject to applicable anti-kickback, fraud and abuse and other healthcare laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm and diminished profits and future earnings.

        Healthcare providers, physicians and third-party payors will play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our future arrangements with third-party payors and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may affect the business or financial

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arrangements and relationships through which we would market, sell and distribute our products. Federal and state healthcare laws and regulations pertaining to fraud and abuse and patients' rights are and will be applicable to our business. Restrictions under applicable federal and state healthcare laws and regulations that may affect our operations (including our marketing, promotion, educational programs, pricing, and relationships with healthcare providers or other entities, among other things) and expose us to areas of risk include the following: (i) the federal healthcare Anti-Kickback Statute; (ii) federal civil and criminal false claims laws and civil monetary penalty laws; (iii) the federal Health Insurance Portability and Accountability Act of 1996, or HIPAA; (iv) HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act, or HITECH; (v) the federal physician sunshine requirements under the Affordable Care Act; and (vi) analogous state and foreign laws and regulations, such as state anti-kickback and false claims laws and state and foreign laws governing the privacy and security of health information in specified circumstances.

        Efforts to ensure that our business arrangements with third parties are compliant with applicable healthcare laws and regulations will involve the expenditure of appropriate, and possibly significant, resources. Nonetheless, it is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, imprisonment, exclusion from government funded healthcare programs, such as Medicare and Medicaid, and the curtailment or restructuring of our operations. If any physicians or other healthcare providers or entities with whom we expect to do business are found to not be in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs.

We will need to grow the size of our organization, and we may experience difficulties in managing this growth.

        As of September 15, 2016, we had 16 full-time and part-time employees, of whom four hold Ph.D. degrees and one holds an M.D. degree. We will need additional managerial, operational, sales, marketing, financial and other resources. Future growth would impose significant added responsibilities on members of management, including:

    identifying, recruiting, maintaining, motivating and integrating additional employees;

    improving our managerial, development, operational and finance systems; and

    expanding our facilities.

        Because of the specialized scientific and managerial nature of our business, we rely heavily on our ability to attract and retain qualified scientific, technical and managerial personnel. The competition for qualified personnel in the pharmaceutical field is intense and as a result, we may be unable to continue to attract and retain qualified personnel necessary for the development of our business. As our operations expand, we will also need to manage additional relationships with various strategic partners, suppliers and other third parties. Our future financial performance and our ability to develop and commercialize DKN-01 or TRX518, if approved, and to compete effectively will depend, in part, on our ability to manage future growth effectively. Our failure to accomplish any of these tasks could prevent us from successfully growing our company.

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We may acquire other assets, form collaborations or make investments in other companies or technologies, that could harm our operating results, dilute our stockholders' ownership, increase our debt or cause us to incur significant expense.

        As part of our business strategy, we may pursue acquisitions of assets, including pre-clinical or clinical stage product candidates, or enter into strategic alliances and collaborations to expand our existing programs and operations. We may not identify or complete these transactions in a timely manner, on a cost-effective basis, or at all, and we may not realize the anticipated benefits of any such transaction, any of which could have a detrimental effect on our financial condition, results of operations and cash flows. We may not be able to find suitable acquisition candidates, and if we make any acquisitions, we may not be able to integrate these acquisitions successfully into our existing business and we may incur additional debt or assume unknown or contingent liabilities in connection therewith. Integration of an acquired company or assets may also disrupt ongoing operations, require the hiring of additional personnel and the implementation of additional internal systems and infrastructure, and require management resources that would otherwise focus on developing our existing business. We may not be able to find suitable strategic alliance or collaboration partners or identify other investment opportunities, and we may experience losses related to any such investments.

        To finance any acquisitions or collaborations, we may choose to issue debt or shares of our common stock as consideration. Any such issuance of shares would dilute the ownership of our stockholders. If the price of our common stock is low or volatile, we may not be able to acquire other assets or companies or fund a transaction using our stock as consideration. Alternatively, it may be necessary for us to raise additional funds for acquisitions through public or private financings. Additional funds may not be available on terms that are favorable to us, or at all.

Risks Related to Our Dependence on Third Parties

We rely, and expect to continue to rely, on third parties to conduct, supervise, and monitor our preclinical studies and clinical trials, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such trials or failing to comply with regulatory requirements.

        We rely on third-party contract research organizations, or CROs, to conduct, supervise, and monitor our preclinical and clinical trials for our product candidates. We expect to continue to rely on third parties, such as CROs, clinical data management organizations, medical institutions, and clinical investigators, to conduct our preclinical studies and clinical trials. While we have agreements governing their activities, we have limited influence over their actual performance and control only certain aspects of their activities. The failure of these third parties to successfully carry out their contractual duties or meet expected deadlines could substantially harm our business, because we may be delayed in completing or unable to complete the clinical trials required to support future approval of our product candidates, or we may not obtain marketing approval for or commercialize our product candidates in a timely manner or at all. Moreover, these agreements might terminate for a variety of reasons, including a failure to perform by the third parties. If we need to enter into alternative arrangements, then that could delay our product development activities and adversely affect our business.

        Our reliance on these third parties for development activities reduces our control over these activities. Nevertheless, we are responsible for ensuring that each of our studies is conducted in accordance with the applicable protocol, legal, regulatory, and scientific standards, and our reliance on the CROs does not relieve us of our regulatory responsibilities. For example, we will remain responsible for ensuring that each of our clinical trials is conducted in accordance with the general investigational plan and protocols for the trial and for ensuring that our preclinical trials are conducted in accordance with GLPs, as appropriate. Moreover, the FDA and comparable foreign regulatory authorities require us to comply with standards, commonly referred to as GCPs, for conducting, recording, and reporting the results of clinical trials to assure that data and reported results are

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credible and accurate and that the rights, integrity, and confidentiality of trial participants are protected. Regulatory authorities enforce these requirements through periodic inspections of trial sponsors, clinical investigators, and trial sites. If we or any of our CROs fail to comply with applicable GCPs or other regulatory requirements, we or our CROs may be subject to enforcement or other legal actions, the clinical data generated in our clinical trials may be deemed unreliable and the FDA or comparable foreign regulatory authorities may require us to perform additional clinical trials.

        In addition, we will be required to report certain financial interests of our third-party investigators if these relationships exceed certain financial thresholds or meet other criteria. The FDA or comparable foreign regulatory authorities may question the integrity of the data from those clinical trials conducted by investigators who may have conflicts of interest.

        We cannot assure you that, upon inspection by a given regulatory authority, such regulatory authority will determine that any of our clinical trials complies with GCP regulations. In addition, our clinical trials must be conducted with product candidates that were produced under cGMP regulations. Our failure to comply with these regulations may require us to repeat clinical trials, which would delay the regulatory approval process. We also are required to register certain clinical trials and post the results of certain completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within specified timeframes. Failure to do so can result in enforcement actions and adverse publicity.

        Our CROs may also have relationships with other entities, some of which may be our competitors, for whom they may also be conducting clinical trials or other therapeutic development activities that could harm our competitive position. In addition, our CROs are not our employees, and except for remedies available to us under our agreements with such CROs, we cannot control whether or not they devote sufficient time and resources to our ongoing clinical, non-clinical, and preclinical programs. If these third parties do not successfully carry out their contractual duties, meet expected deadlines or conduct our preclinical studies or clinical trials in accordance with regulatory requirements or our stated protocols, if they need to be replaced or if the quality or accuracy of the data they obtain is compromised due to the failure to adhere to our protocols, regulatory requirements or for other reasons, our trials may be repeated, extended, delayed, or terminated and we may not be able to obtain, or may be delayed in obtaining, marketing approvals for our product candidates and will not be able to, or may be delayed in our efforts to, successfully commercialize our product candidates, or we or they may be subject to regulatory enforcement actions. As a result, our results of operations and the commercial prospects for our product candidates would be harmed, our costs could increase and our ability to generate revenues could be delayed. To the extent we are unable to successfully identify and manage the performance of third-party service providers in the future, our business may be materially and adversely affected.

        If any of our relationships with these third-party CROs terminate, we may not be able to enter into arrangements with alternative CROs or to do so on commercially reasonable terms. Switching or adding additional CROs involves additional cost and requires management time and focus. In addition, there is a natural transition period when a new CRO commences work. As a result, delays could occur, which could compromise our ability to meet our desired development timelines. Though we carefully manage our relationships with our CROs, there can be no assurance that we will not encounter similar challenges or delays in the future or that these delays or challenges will not have a material adverse impact on our business, financial condition and prospects, and results of operations.

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If the contract manufacturers upon whom we rely fail to produce our product candidates or components in the volumes that we require on a timely basis, or to comply with stringent regulations applicable to biopharmaceutical manufacturers, we may face delays in the development and commercialization of, or be unable to meet demand for, our product candidates and may lose potential revenues.

        We do not manufacture any of our product candidates, and we do not currently plan to develop any capacity to do so. We utilize third-party contract manufacturing organizations, or CMOs, to manufacture the clinical trial material of DKN-01 and TRX518 and expect to do so for commercial products, if approved. We do not have any long-term commitments from our CMOs for clinical trial material or guaranteed prices for our product candidates. Any delays in obtaining adequate supplies with respect to our product candidates will delay the development or commercialization of our product candidates.

        Our product candidates compete with other products and product candidates for access to contract manufacturing facilities. There are a limited number of CMOs that operate under cGMP regulations and that are both capable of manufacturing for us and willing to do so. If our existing CMOs, or any new third party CMOs that we engage in the future to manufacture our product candidates for our clinical trials, should cease to continue to do so for any reason, we likely would experience delays in obtaining sufficient quantities of our product candidates for us to advance our clinical trials while we identify and qualify replacement suppliers. Further, even if we do establish such collaborations or arrangements, our CMOs may breach, terminate, or not renew these agreements. We may not succeed in our efforts to establish sufficient manufacturing relationships or other alternative arrangements to meet our needs for any of our existing or future product candidates. If for any reason we are unable to obtain adequate supplies of our product candidates, it will be more difficult for us to conduct clinical trials, develop our product candidates and operate our business.

        Any problems or delays we experience in preparing for commercial-scale manufacturing of a product candidate or component may result in a delay in FDA approval of the product candidate or may impair our ability to manufacture commercial quantities or such quantities at an acceptable cost, which could result in the delay, prevention, or impairment of clinical development and commercialization of our product candidates and could adversely affect our business. Furthermore, if our commercial CMOs fail to deliver the required commercial quantities of our product candidates on a timely basis and at commercially reasonable prices, we would likely be unable to meet demand for our products and we would lose potential revenues.

        The manufacture of pharmaceutical products requires significant expertise and capital investment, including the development of advanced manufacturing techniques and process controls. Manufacturers of therapeutics often encounter difficulties in production, particularly in scaling up initial production. These problems include difficulties with production costs and yields, quality control, including stability of the product candidate and quality assurance testing, shortages of qualified personnel, and compliance with strictly enforced federal, state, and foreign regulations. Our CMOs may not perform as agreed or may have a failure of a manufacturing campaign. Any changes or deviations in a manufacturing process may result in the failure of the product to meet the specifications. If our CMOs were to encounter any of these difficulties, our ability to provide product candidates to patients in our clinical trials and for commercial use, if approved, would be jeopardized. Reliance on third-party CMOs entails exposure to risks to which we would not be subject if we manufactured the product candidate ourselves, including:

    inability to negotiate manufacturing agreements with CMOs under commercially reasonable terms;

    reduced day-to-day control over the manufacturing process for our product candidates as a result of using third-party CMOs for all aspects of manufacturing activities;

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    reduced control over the protection of our trade secrets and know-how from misappropriation or inadvertent disclosure;

    termination or nonrenewal of manufacturing agreements with third parties in a manner or at a time that may be costly or damaging to us or result in delays in the development or commercialization of our product candidates; and

    disruptions to the operations of our third-party CMOs caused by conditions unrelated to our business or operations, including the bankruptcy of the CMO.

        In addition, all CMOs of our product candidates and therapeutic substances must comply with cGMP requirements enforced by the FDA that are applicable to both finished product and their active components used both for clinical and commercial supply, through its facilities inspection program. Our CMOs must be approved by the FDA pursuant to inspections that will be conducted after we submit our marketing applications to the agency. Our CMOs will also be subject to continuing FDA and other regulatory authority inspections should we receive marketing approval. Further, we, in cooperation with our CMOs, must supply all necessary chemistry, manufacturing, and control documentation in support of a BLA on a timely basis. The cGMP requirements include quality control, quality assurance, and the maintenance of records and documentation. Manufacturers of our product candidates and therapeutic substances may be unable to comply with our specifications, these cGMP requirements and with other FDA, state, and foreign regulatory requirements. Poor control of production processes can lead to the introduction of adventitious agents or other contaminants, or to inadvertent changes in the properties or stability of product candidates that may not be detectable in final product testing. If our CMOs cannot successfully manufacture material that conforms to our specifications and the strict regulatory requirements of the FDA or other regulatory authorities, they will not be able to secure or maintain regulatory approval for their manufacturing facilities. Any such deviations may also require remedial measures that may be costly and/or time-consuming for us or a third party to implement and that may include the temporary or permanent suspension of a clinical trial or commercial sales or the temporary or permanent closure of a facility. Any such remedial measures imposed upon us or third parties with whom we contract could materially harm our business.

        While we are ultimately responsible for the manufacture of our product candidates and therapeutic substances, other than through our contractual arrangements, we have little control over our CMOs' compliance with these regulations and standards. If the FDA or a comparable foreign regulatory authority does not approve these facilities for the manufacture of our product candidates or if it withdraws any such approval in the future, we may need to find alternative manufacturing facilities, which would significantly impact our ability to develop, obtain regulatory approval for or market our product candidates, if approved. A failure to comply with these requirements may result in regulatory enforcement actions against our CMOs or us, including fines and civil and criminal penalties, including imprisonment, suspension or restrictions of production, suspension, injunctions, delay or denial of product approval or supplements to approved products, clinical holds or termination of clinical studies, warning or untitled letters, regulatory authority communications warning the public about safety issues with the biologic, refusal to permit the import or export of the products, product seizure, detention, or recall, operating restrictions, suits under the civil False Claims Act, corporate integrity agreements, consent decrees, or withdrawal of product approval. If the safety of any quantities supplied is compromised due to our CMOs' failure to adhere to applicable laws or for other reasons, we may not be able to obtain regulatory approval for or successfully commercialize our product candidates.

        Any failure or refusal to supply sufficient quantities of our product candidates would delay, prevent or impair our clinical development or commercialization efforts. Any change in our CMO could be costly because the commercial terms of any new arrangement could be less favorable and because the expenses relating to the transfer of necessary technology and processes could be significant. There are significant requirements prior to receiving FDA approval for the transfer of manufacturing process for a therapeutic antibody product to a new manufacturing facility.

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        We also rely on third parties to store and distribute our product candidates for the clinical trials that we conduct. Any performance failure on the part of our distributors could delay clinical development of our product candidates, producing additional losses.

Any collaboration arrangements that we may enter into in the future may not be successful, which could adversely affect our ability to develop and commercialize our product candidates.

        For our current or future product candidates, we may in the future determine to collaborate with other pharmaceutical and biotechnology companies for their development and potential commercialization. We face significant competition in seeking appropriate collaborators. Our ability to reach a definitive agreement for collaboration will depend, among other things, upon our assessment of the collaborator's resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator's evaluation of a number of factors. Our future collaboration arrangements, if any, may not be successful, and the success of them will depend heavily on the efforts and activities of our collaborators. Collaborators generally have significant discretion in determining the efforts and resources that they will apply to these collaboration arrangements. Disagreements between parties to a collaboration arrangement regarding clinical development and commercialization matters can lead to delays in the development process or commercializing the applicable product candidate and, in some cases, termination of the collaboration arrangement. We may not identify or complete any collaboration in a timely manner, on a cost-effective basis, or at all, and we may not realize the anticipated benefits of any such transaction, any of which could have a detrimental effect on our financial condition, results of operations and cash flows.

Risks Related to Legal and Compliance Matters

If we fail to comply with federal and state healthcare laws, including fraud and abuse and health and other information privacy and security laws, we could face substantial penalties and our business, financial condition, results of operations, and prospects could be adversely affected.

        As a biopharmaceutical company, we are subject to many federal and state healthcare laws, including those described in the Government Regulation and Product Approval section of this prospectus, such as the federal Anti-Kickback Statute, the federal civil and criminal False Claims Act, the civil monetary penalties statute, the Medicaid Drug Rebate statute and other price reporting requirements, the Veterans Health Care Act of 1992, the federal Health Insurance Portability and Accountability Act of 1996 (as amended by the Health Information Technology for Economics and Clinical Health Act), the Foreign Corrupt Practices Act of 1977, the Patient Protection and Affordable Care Act of 2010, and similar state laws. Even though we do not and will not control referrals of healthcare services or bill directly to Medicare, Medicaid or other third-party payors, certain federal and state healthcare laws, and regulations pertaining to fraud and abuse and patients' rights are and will be applicable to our business. We would be subject to healthcare fraud and abuse and patient privacy regulation by both the federal government and the states in which we conduct our business.

        If we or our operations are found to be in violation of any federal or state healthcare law, or any other governmental regulations that apply to us, we may be subject to penalties, including civil, criminal, and administrative penalties, damages, fines, disgorgement, debarment from government contracts, and refusal of orders under existing contracts, exclusion from participation in U.S. federal or state health care programs, corporate integrity agreements, and the curtailment or restructuring of our operations, any of which could materially adversely affect our ability to operate our business and our financial results. If any of the physicians or other healthcare providers or entities with whom we expect to do business, including our collaborators, is found not to be in compliance with applicable laws, it may be subject to criminal, civil or administrative sanctions, including but not limited to, exclusions from participation in government healthcare programs, which could also materially affect our business.

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        Although an effective compliance program can mitigate the risk of investigation and prosecution for violations of these laws, the risks cannot be entirely eliminated. Moreover, achieving and sustaining compliance with applicable federal and state privacy, security, and fraud laws may prove costly. Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management's attention from the operation of our business.

We are subject to new legislation, regulatory proposals and healthcare payor initiatives that may increase our costs of compliance, and adversely affect our ability to market our products, obtain collaborators, and raise capital.

        In the United States and some foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our ability, or the ability of our collaborators, to profitably sell any products for which we obtain marketing approval. We believe that there is the possibility that healthcare and pricing reform measures may be adopted in the future that may result in more rigorous coverage criteria and in additional downward pressure on the price that we, or our collaborators, may receive for any approved products. Any reduction in reimbursement from Medicare or other government healthcare programs may result in a similar reduction in payments from private payors. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability or commercialize our products.

        Legislative and regulatory proposals may also be made to expand post-approval requirements and restrict sales and promotional activities. We cannot be sure whether additional legislative changes will be enacted, or whether the FDA regulations, guidance or interpretations will be changed, or what the impact of such changes on the marketing approvals of our product candidates, if any, may be. In addition, increased scrutiny by the U.S. Congress of the FDA's approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing testing and other requirements.

        In addition, there have been a number of other legislative and regulatory proposals aimed at changing the biopharmaceutical industry. For instance, the Drug Quality and Security Act imposes obligations on manufacturers of biopharmaceutical products related to product tracking and tracing. Among the requirements of this legislation, manufacturers are required to provide certain information regarding the product to individuals and entities to which product ownership is transferred, will be required to label products with a product identifier, and are required keep certain records regarding the product. The transfer of information to subsequent product owners by manufacturers will eventually be required to be done electronically. Manufacturers are also be required to verify that purchasers of the manufacturers' products are appropriately licensed. Further, manufactures have product investigation, quarantine, disposition, and FDA and trading partner notification responsibilities related to counterfeit, diverted, stolen, and intentionally adulterated products that would result in serious adverse health consequences of death to humans, as well as products that are the subject of fraudulent transactions or which are otherwise unfit for distribution such that they would be reasonably likely to result in serious health consequences or death.

        As a result of these and other new legislative and regulatory proposals, we may determine to change our current manner of operation, provide additional benefits or change our contract arrangements, any of which could have a material adverse effect on our business, financial condition, and results of operations.

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Our employees, independent contractors, consultants, commercial partners, principal investigators, CMOs or CROs may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which could have a material adverse effect on our business.

        We are exposed to the risk of fraud or other misconduct. Misconduct by employees, independent contractors, consultants, commercial partners, principal investigators, or CROs could include intentional, reckless, negligent, or unintentional failures to comply with FDA regulations, comply with applicable fraud and abuse laws, provide accurate information to the FDA, report financial information or data accurately or disclose unauthorized activities to us. This misconduct could also involve the improper use or misrepresentation of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. It is not always possible to identify and deter this type of misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, financial condition, and results of operations, including the imposition of significant fines or other sanctions.

Our business and operations would suffer in the event of system failures.

        Computer systems, ours and those of our CROs, CMOs and other contractors, are vulnerable to damage from computer viruses, unauthorized access, natural disasters, terrorism, war, and telecommunication and electrical failures. If such an event were to occur and cause interruptions in our operations, it could result in a material disruption of our product candidate development programs. For example, the loss of clinical trial data from completed, ongoing or planned clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. To the extent that any disruption or security breach were to result in a loss of or damage to our data or applications, or inappropriate disclosure of personal, confidential or proprietary information, we could incur liability and the further development of any of our product candidates could be delayed.

Risks Related to Our Intellectual Property

If we are unable to protect our intellectual property rights or if our intellectual property rights are inadequate for our technology and product candidates, our competitive position could be harmed.

        Our commercial success will depend in large part on our ability to obtain and maintain patent and other intellectual property protection in the U.S. and other countries with respect to our proprietary technology and products. We rely on patent, copyright and trademark laws, and confidentiality, licensing and other agreements with employees and third parties, all of which offer only limited protection. We seek to protect our proprietary position by filing and prosecuting patent applications in the U.S. and abroad related to our novel technologies and products that are important to our business.

        The patent positions of biotechnology and pharmaceutical companies generally are highly uncertain, involve complex legal and factual questions and have in recent years been the subject of much litigation. As a result, the issuance, scope, validity, enforceability and commercial value of our patents, including those patent rights licensed to us by third parties, are highly uncertain. The steps we or our licensor have taken to protect our proprietary rights may not be adequate to preclude misappropriation of our proprietary information or infringement of our intellectual property rights, both inside and outside the U.S. Further, the examination process may require us or our licensor to narrow the claims for our pending patent applications, which may limit the scope of patent protection that may be obtained if these applications issue. The rights already granted under any of our currently issued patents or those licensed to us and those that may be granted under future issued patents may not provide us with the proprietary protection or competitive advantages we are seeking. If we or our

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licensor are unable to obtain and maintain patent protection for our technology and products, or if the scope of the patent protection obtained is not sufficient, our competitors could develop and commercialize technology and products similar or superior to ours, and our ability to successfully commercialize our technology and products may be adversely affected. It is also possible that we or our licensor will fail to identify patentable aspects of inventions made in the course of our development and commercialization activities before it is too late to obtain patent protection on them.

        With respect to patent rights, we do not know whether any of the pending patent applications for any of our compounds will result in the issuance of patents that protect our technology or products, or if any of our or our licensor's issued patents will effectively prevent others from commercializing competitive technologies and products. Patents in the field of therapeutic monoclonal antibodies are frequently limited in scope based on the sequence of amino acids that form the antibody. A portion of our intellectual property portfolio is limited by the amino acid sequence of our product candidates. Other competing companies may have therapeutic antibodies to the same target as our product candidates that have a different amino acid sequence and as a result may not be determined to infringe on patents which are limited by amino acid sequence. Even for those patent applications which are defined by the target of a therapeutic antibody and not limited by an amino acid sequence, we cannot be certain that other companies with antibodies to these targets have not reported unanticipated findings or can otherwise avoid or overcome the claims in our intellectual property.

        Our pending applications cannot be enforced against third parties practicing the technology claimed in such applications unless and until a patent issues from such applications. Because the issuance of a patent is not conclusive as to its inventorship, scope, validity or enforceability, issued patents that we own or have licensed from third parties may be challenged in the courts or patent offices in the U.S. and abroad. Such challenges may result in the loss of patent protection, the narrowing of claims in such patents or the invalidity or unenforceability of such patents, which could limit our ability to stop others from using or commercializing similar or identical technology and products, or limit the duration of the patent protection for our technology and products. Protecting against the unauthorized use of our or our licensors' patented technology, trademarks and other intellectual property rights is expensive, difficult and may in some cases not be possible. In some cases, it may be difficult or impossible to detect third-party infringement or misappropriation of our intellectual property rights, even in relation to issued patent claims, and proving any such infringement may be even more difficult.

Our granted European patent for TRX518 and its uses, which is of significant value to us, was challenged in European Patent Office Opposition proceedings, and a successful challenge could limit our future revenues.

        A patent covering TRX518 and its uses was granted to us by the European Patent Office. Three oppositions to this patent were filed by at least two major pharmaceutical companies, among others. Opposition proceedings took place earlier this year and the Opposition Division of the European Patent Office that heard the case issued an interlocutory decision indicating that our patent should be maintained with modified claims that are narrower than the claims as originally granted. Nonetheless, we believe that the claims deemed allowable by the Opposition Division still sufficiently cover TRX518 and its uses. Nonetheless, we have filed an appeal of the decision of the Opposition Division seeking to obtain broader claims that more closely reflect the claims as granted in the patent. We cannot assure you that our appeal will have any success. Should the decision of the Opposition Division stand in whole or in part, our ability to collect royalties on European sales of our products may be more limited than the broader claims we were originally granted, which could have an adverse effect on our business, financial condition and results of operations. In addition, the cost of the opposition appeal and any further proceedings could be material. Should the decision of the Opposition Division be adverse to us, our ability to prevent others from marketing competitor products would be limited.

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Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain and could harm our business.

        Our commercial success depends upon our ability to develop, manufacture, market and sell DKN-01 or TRX518. We may become party to, or threatened with, future adversarial proceedings or litigation regarding intellectual property rights with respect to DKN-01 or TRX518, including interference or derivation proceedings before the U.S. Patent and Trademark Office, or USPTO. Third parties may assert infringement claims against us based on existing patents or patents that may be granted in the future. If we are found to infringe a third party's intellectual property rights, we could be required to obtain a license from such third party to continue commercializing DKN-01 or TRX518. However, we may not be able to obtain any required license on commercially reasonable terms or at all. Under certain circumstances, we could be forced, including by court order, to cease commercializing DKN-01 or TRX518. In addition, in any such proceeding or litigation, we could be found liable for monetary damages. A finding of infringement could prevent us from commercializing DKN-01 or TRX518 or force us to cease some of our business operations, which could materially harm our business. Any claims by third parties that we have misappropriated their confidential information or trade secrets could have a similar negative impact on our business.

        While DKN-01 and TRX518 is in pre-clinical studies and clinical trials, we believe that the use of DKN-01 and TRX518 in these preclinical studies and clinical trials falls within the scope of the exemptions provided by 35 U.S.C. Section 271(e) in the U.S., which exempts from patent infringement liability activities reasonably related to the development and submission of information to the FDA. As DKN-01 or TRX518 progresses toward commercialization, the possibility of a patent infringement claim against us increases. We attempt to ensure that DKN-01 and TRX518, the methods we employ to manufacture it, as well as the methods for its use we intend to promote, do not infringe other parties' patents and other proprietary rights. There can be no assurance they do not, however, and competitors or other parties may assert that we infringe their proprietary rights in any event.

We may not be able to protect our intellectual property rights throughout the world.

        Filing, prosecuting and defending patents on DKN-01 or TRX518 and any future product candidates throughout the world would be prohibitively expensive, and our or our licensor's intellectual property rights in some countries outside the U.S. can be less extensive than those in the U.S. In addition, the laws and practices of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the U.S. Consequently, we and our licensor may not be able to prevent third parties from practicing our and our licensor's inventions in all countries outside the U.S., or from selling or importing products made using our and our licensor's inventions in and into the U.S. or other jurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products, and may export otherwise infringing products to territories where we or our licensor have patent protection, but where enforcement is not as strong as that in the U.S. These products may compete with our products in jurisdictions where we do not have any issued patents and our patent claims or other intellectual property rights may not be effective or sufficient to prevent them from so competing.

        Many companies have encountered significant problems in protecting and defending intellectual property rights in certain foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents and other intellectual property protection, particularly those relating to biopharmaceuticals, which could make it difficult for us to stop the infringement of our or our licensor's patents or marketing of competing products in violation of our proprietary rights generally in those countries. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial cost and divert our efforts and attention from other aspects of our business, could put our and our licensor's patents at risk of being invalidated or interpreted narrowly and our and our licensor's patent applications at risk of not issuing and could provoke third

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parties to assert claims against us or our licensor. We or our licensor may not prevail in any lawsuits that we or our licensor initiate and the damages or other remedies awarded, if any, may not be commercially meaningful.

        The laws of certain foreign countries may not protect our rights to the same extent as the laws of the U.S., and these foreign laws may also be subject to change. For example, methods of treatment and manufacturing processes may not be patentable in certain jurisdictions, and the requirements for patentability may differ in certain countries, particularly developing countries. Furthermore, generic drug manufacturers or other competitors may challenge the scope, validity or enforceability of our or our licensor's patents, requiring us or our licensor to engage in complex, lengthy and costly litigation or other proceedings. Generic drug or biosimilar manufacturers may develop, seek approval for, and launch generic or biosimilar versions of our products. Many countries, including European Union countries, India, Japan and China, have compulsory licensing laws under which a patent owner may be compelled under certain circumstances to grant licenses to third parties. In those countries, we and our licensor may have limited remedies if patents are infringed or if we or our licensor are compelled to grant a license to a third party, which could materially diminish the value of those patents. This could limit our potential revenue opportunities. Accordingly, our and our licensor's efforts to enforce intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we own or license.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submissions, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

        Periodic maintenance fees on any issued patent are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patent. The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of a patent or patent application include, but are not limited to, failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If we or our licensor fail to maintain the patents and patent applications covering our product candidates, our competitive position would be adversely affected.

We may become involved in lawsuits to protect or enforce our intellectual property, which could be expensive, time consuming and unsuccessful and have a material adverse effect on the success of our business.

        Competitors may infringe our patents or misappropriate or otherwise violate our intellectual property rights. To counter infringement or unauthorized use, litigation may be necessary in the future to enforce or defend our intellectual property rights, to protect our trade secrets or to determine the validity and scope of our own intellectual property rights or the proprietary rights of others. Also, third parties may initiate legal proceedings against us or our licensor to challenge the validity or scope of intellectual property rights we own or control. These proceedings can be expensive and time consuming. Many of our current and potential competitors have the ability to dedicate substantially greater resources to defend their intellectual property rights than we can. Accordingly, despite our efforts, we may not be able to prevent third parties from infringing upon or misappropriating our intellectual property. Litigation could result in substantial costs and diversion of management resources, which could harm our business and financial results. In addition, in an infringement proceeding, a court may decide that a patent owned by or licensed to us is invalid or unenforceable, or may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the

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technology in question. An adverse result in any litigation proceeding could put one or more of our patents at risk of being invalidated, held unenforceable or interpreted narrowly. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could have a material adverse effect on the price of shares of our common stock.

Risks Related to Our Being a Public Company

We are an "emerging growth company" and we intend to take advantage of reduced disclosure and governance requirements applicable to emerging growth companies, which could result in our common stock being less attractive to investors.

        We are an "emerging growth company," as defined in the JOBS Act, and we intend to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved. We cannot predict if investors will find our common stock less attractive because we will rely on these exemptions. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock, our stock price may be more volatile and it may be difficult for us to raise additional capital as and when we need it. If we are unable to raise additional capital as and when we need it, our financial condition and results of operations may be materially and adversely affected.

        We may take advantage of these reporting exemptions until we are no longer an emerging growth company, which in certain circumstances could be for up to five years. We will remain an "emerging growth company" until the earliest of (a) the last day of the first fiscal year in which our annual gross revenues exceed $1.0 billion, (b) the date that we become a "large accelerated filer" as defined in Rule 12b-2 under the Securities Exchange Act of 1934, as amended, or the Exchange Act, which would occur if the market value of our shares that are held by non-affiliates exceeds $700 million as of the last business day of our most recently completed second fiscal quarter, (c) the date on which we have issued more than $1.0 billion in nonconvertible debt during the preceding three-year period and (d) the last day of our fiscal year containing the fifth anniversary of the date on which shares of our common stock become publicly traded in the U.S.

If we fail to maintain an effective system of internal control over financial reporting in the future, we may not be able to accurately report our financial condition, results of operations or cash flows, which may adversely affect investor confidence in us and, as a result, the value of our common stock.

        The Sarbanes-Oxley Act requires, among other things, that we maintain effective internal controls for financial reporting and disclosure controls and procedures. Beginning with our second annual report following the date that the Registration Statement becomes effective, we will be required, under Section 404 of the Sarbanes-Oxley Act, to furnish a report by management on, among other things, the effectiveness of our internal control over financial reporting. This assessment will need to include disclosure of any material weaknesses identified by our management in our internal control over financial reporting. A material weakness is a deficiency, or combination of deficiencies, in internal control over financial reporting that results in more than a reasonable possibility that a material misstatement of annual or interim financial statements will not be prevented or detected on a timely basis. Section 404 of the Sarbanes-Oxley Act also generally requires an attestation from our

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independent registered public accounting firm on the effectiveness of our internal control over financial reporting. However, for as long as we remain an emerging growth company as defined in the JOBS Act, we intend to take advantage of the exemption permitting us not to comply with the independent registered public accounting firm attestation requirement.

        Our compliance with Section 404 will require that we incur substantial accounting expense and expend significant management efforts. We currently do not have an internal audit group, and we will need to hire additional accounting and financial staff with appropriate public company experience and technical accounting knowledge, and compile the system and process documentation necessary to perform the evaluation needed to comply with Section 404. We may not be able to complete our evaluation, testing and any required remediation in a timely fashion. During the evaluation and testing process, if we identify one or more material weaknesses in our internal control over financial reporting, we will be unable to assert that our internal control over financial reporting is effective. We cannot assure you that there will not be material weaknesses or significant deficiencies in our internal control over financial reporting in the future. Any failure to maintain internal control over financial reporting could severely inhibit our ability to accurately report our financial condition, results of operations or cash flows. If we are unable to conclude that our internal control over financial reporting is effective, or if our independent registered public accounting firm determines we have a material weakness or significant deficiency in our internal control over financial reporting once that firm begins its Section 404 reviews, we could lose investor confidence in the accuracy and completeness of our financial reports, the market price of our common stock could decline, and we could be subject to sanctions or investigations by the NASDAQ stock market, the Commission or other regulatory authorities. Failure to remedy any material weakness in our internal control over financial reporting, or to implement or maintain other effective control systems required of public companies, could also restrict our future access to the capital markets.

Our disclosure controls and procedures may not prevent or detect all errors or acts of fraud.

        Upon consummation of this offering, we will become subject to the periodic reporting requirements of the Exchange Act. Our disclosure controls and procedures are designed to reasonably assure that information required to be disclosed by us in reports we file or submit under the Exchange Act is accumulated and communicated to management, recorded, processed, summarized and reported within the time periods specified in the rules and forms of the Commission. We believe that any disclosure controls and procedures or internal controls and procedures, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met.

        These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements or insufficient disclosures due to error or fraud may occur and not be detected.

We will incur increased costs as a result of operating as a public company, and our management will be required to devote substantial time to new compliance initiatives.

        As a public company, we will incur significant legal, accounting and other expenses that we did not incur as a private company, and these expenses may increase even more after we are no longer an "emerging growth company." We will be subject to the reporting requirements of the Exchange Act, the Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Protection Act, as well as rules adopted, and to be adopted, by the Commission and NASDAQ stock market. Our management and other personnel will need to devote a substantial amount of time to these compliance initiatives. Moreover, we expect these rules and regulations to substantially increase our legal and financial

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compliance costs and to make some activities more time-consuming and costly. We estimate that we will incur approximately $1.0 to $1.5 million in incremental costs per year associated with being a publicly traded company, although it is possible that our actual incremental costs will be higher than we currently estimate. The increased costs will increase our net loss. For example, we expect these rules and regulations to make it more expensive for us to obtain director and officer liability insurance and we may be required to incur substantial costs to maintain sufficient coverage. We cannot predict or estimate the amount or timing of additional costs we may incur to respond to these requirements. The impact of these requirements could also make it more difficult for us to attract and retain qualified persons to serve on our board of directors or as executive officers.

Risks Related to our Common Stock

Because we do not anticipate paying any cash dividends on our capital stock in the foreseeable future, capital appreciation, if any, will be your sole source of gain.

        We have never declared or paid cash dividends on our capital stock. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business. As a result, capital appreciation, if any, of our common stock will be your sole source of gain for the foreseeable future.

Sales of a substantial number of shares of our common stock in the public market could cause our stock price to fall.

        Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. After the merger, holders of an aggregate of                shares of our common stock will have rights, subject to certain conditions, to require us to file registration statements covering their shares or to include their shares in registration statements that we may file for ourselves or other stockholders. We also intend to register all shares of common stock that we may issue under our equity compensation plans on Form S-8. Once we register these shares, they can be freely sold in the public market upon issuance, subject to volume limitations applicable to affiliates under Rule 144 under the Securities Act.

Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to our equity incentive plans, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.

        Following the consummation of the merger, if Leap's existing stockholders or holders of Macrocure ordinary shares receiving shares of Leap common stock in the merger sell substantial amounts of Leap common stock in the public market, or investors perceive that these sales could occur, the market price of Leap common stock could decrease significantly.

        We expect that significant additional capital will be needed in the future to continue our planned operations. To raise capital, we may sell substantial amounts of common stock or securities convertible into or exchangeable for common stock. These future issuances of common stock or common stock-related securities, together with the exercise of stock options, warrants outstanding or granted in the future and any additional shares issued in connection with acquisitions, if any, may result in material dilution to our investors. Such sales may also result in material dilution to our existing stockholders, and new investors could gain rights, preferences and privileges senior to those of holders of our common stock, including shares of common stock sold in this offering.

        Pursuant to our equity incentive plans, our compensation committee is authorized to grant equity-based incentive awards to our directors, executive officers and other employees and service providers. While no shares are currently available for future grant under our Amended and Restated 2012 Equity Incentive Plan, the number of shares of our common stock available for future grant under our 2016

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Equity Incentive Plan will representing a number of shares of Leap common stock that, together with the out-of-the-money options outstanding at the effective time of the merger, represents 8% of Leap's fully diluted capitalization. Future equity incentive grants and issuances of common stock under our 2016 Equity Incentive Plan may have an adverse effect on the market price of our common stock.

Some provisions of our charter documents and Delaware law may have anti-takeover effects that could discourage an acquisition of us by others, even if an acquisition would be beneficial to our stockholders and may prevent attempts by our stockholders to replace or remove our current management.

        Provisions in our certificate of incorporation and bylaws, which we refer to as the New Leap Charter and New Leap Bylaws, which will become effective in connection with consummation of the merger, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us or increase the cost of acquiring us, even if doing so would benefit our stockholders, or remove our current management. These include provisions that will:

    permit our board of directors to issue up to 10 million shares of preferred stock, with any rights, preferences and privileges as it may designate;

    provide that all vacancies on our board of directors, including as a result of newly created directorships, may, except as otherwise required by law, be filled by the affirmative vote of a majority of directors then in office, even if less than a quorum;

    establish a classified board of directors such that only one of three classes of directors is elected each year;

    provide that directors can only be removed for cause;

    require that any action to be taken by our stockholders must be effected at a duly called annual or special meeting of stockholders and not be taken by written consent;

    provide that stockholders seeking to present proposals before a meeting of stockholders or to nominate candidates for election as directors at a meeting of stockholders must provide advance notice in writing, and also specify requirements as to the form and content of a stockholder's notice;

    require that the amendment of certain provisions of our certificate of incorporation relating to anti-takeover measures may only be approved by a vote of 66 2 / 3 % (or, in certain limited circumstances, 75%) of our outstanding capital stock;

    not provide for cumulative voting rights, thereby allowing the holders of a majority of the shares of common stock entitled to vote in any election of directors to elect all of the directors standing for election; and

    provide that special meetings of our stockholders may be called only by the board of directors or by such person or persons designated by a majority of the board of directors to call such meetings.

        These provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors, who are responsible for appointing the members of our management. Because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, which may discourage, delay or prevent someone from acquiring us or merging with us whether or not it is desired by or beneficial to our stockholders. Under Delaware law, a corporation may not, in general, engage in a business combination with any holder of 15% or more of its capital stock unless the holder has held the stock for three years or, among other things, the board of directors has approved the transaction. Any provision of our certificate of incorporation or bylaws or Delaware law that has the effect of delaying or deterring a change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock, and could also affect the price that some investors are willing to pay for our common stock.

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INFORMATION ABOUT THE MACROCURE SHAREHOLDER MEETING

        In order for the merger to become effective, certain matters related to the merger must be approved by the shareholders of Macrocure at a general special meeting of Macrocure's shareholders.

        A copy of the Macrocure proxy statement that is being mailed to Macrocure's shareholders in connection with the merger has been filed as an exhibit to this Registration Statement of which this prospectus forms a part. Macrocure's shareholders are urged to read the Macrocure proxy statement in its entirety. The Macrocure proxy statement is first being mailed or delivered to Macrocure's shareholders, together with this prospectus, on or about                        ,             .

The Macrocure Shareholder Meeting

        Pursuant to Section 320 of the Companies Law, Macrocure is convening a special meeting of its shareholders, or the Macrocure Shareholder Meeting, to consider and approve the merger. The Macrocure shareholders meeting will be held on                        ,            beginning at         :         a.m., at                        .

        The Macrocure board has fixed                        , 2016, as the Macrocure record date for determination of Macrocure shareholders entitled to vote at the Macrocure Shareholder Meeting. Accordingly, only holders of record of shares of Macrocure ordinary shares at the close of business on                                ,             will be entitled to vote at the Macrocure Shareholder Meeting. Each holder of record of Macrocure ordinary shares on the Macrocure record date is entitled to cast one vote per share, in person or by a properly executed proxy, at the Macrocure Shareholder Meeting. As of the Macrocure record date, there were                    Macrocure ordinary shares outstanding and entitled to vote, which were held by                holders of record.

Voting at the Macrocure Shareholder Meeting

        The presence, in person or by proxy, of two or more shareholders possessing at least 25% of Macrocure's voting power will constitute a quorum at the Macrocure Shareholder Meeting. In the absence of a quorum within 30 minutes of the scheduled time for the Macrocure Shareholder Meeting, the meeting will be adjourned until the same day of the following week (                day,                         , 2016) at the same time and place. At such adjourned meeting, the presence of any two shareholders in person or by proxy will constitute a quorum.

        Pursuant to the Macrocure Articles of Association and Section 320 of the Companies Law, the affirmative vote of the holders of a majority of the Macrocure ordinary shares present at the Macrocure Shareholder Meeting, voting together as a single class, is required to approve and adopt the merger proposal, excluding abstentions and broker non-votes and excluding any Macrocure ordinary shares that are held by Leap, Merger Sub or by any person holding at least 25% of the means of control of either of them, or anyone acting on behalf of either of them, including any of their affiliates. Abstentions and broker non-votes will be considered present at the Macrocure Shareholder Meeting for the purpose of calculating a quorum.

        As discussed below in the section entitled "Other Related Agreements—Voting Agreements", certain holders of Macrocure ordinary shares have entered into voting agreements with Leap, dated as of August 29, 2016, and certain holders of Leap common stock have entered into Voting Agreements with Macrocure, dated as of August 29, 2016. Collectively, the Macrocure shareholders that have signed voting agreements hold a total of 9,574,834 shares (excluding additional shares issuable upon exercise of outstanding options and warrants), representing approximately 53.4% percent of the currently outstanding voting power of the Macrocure ordinary shares. Collectively, the Leap stockholders that have signed voting agreements hold 100% of the currently outstanding voting power of all Leap capital stock.

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        The merger must be approved by shareholders holding a majority in voting power of Macrocure ordinary shares present (in person or by proxy) at the Macrocure Shareholder Meeting, excluding abstentions and broker non-votes and excluding any Macrocure ordinary shares that are held by Leap, Merger Sub or by any person holding at least 25% of the means of control of either of them, or anyone acting on behalf of either of them, including any of their affiliates. Voting at the Macrocure Shareholder Meeting will be by ballot. Forms of proxies of holders of Macrocure ordinary shares for the Macrocure Shareholder Meeting must be returned prior to                                , 20    , at        :         a.m. Forms of proxies not so returned may be valid if handed to the chairman prior to the start of the Macrocure Shareholder Meeting, at the discretion of the chairman.

        Pursuant to Section 323 of the Companies Law, if the appropriate majority is obtained at the Macrocure Shareholder Meeting in favor of the merger, a minimum of 30 days must elapse from the date of the approval of the merger by the shareholders of Macrocure (and Merger Sub) before the merger can become effective.

        At the meeting, in addition to the merger, the merger agreement and related matters, shareholders of Macrocure will be asked to vote upon a number of compensation and other similar matters, the approval for which is required under Israeli law. These will be discussed in greater detail in the proxy statement to be sent to Macrocure shareholders by Macrocure.

Solicitation of Proxies

        This prospectus, the Macrocure proxy statement and its accompanying forms of proxy are being mailed by Macrocure to Macrocure shareholders in connection with the solicitation of proxies by Macrocure for the Macrocure shareholders meeting. The cost of soliciting proxies in the accompanying forms will be borne by Macrocure. Macrocure has not retained any independent soliciting agent. Proxies may be solicited in person or by telephone or telegram by the directors, executive officers and employees of Macrocure, who will not receive additional compensation for such activities.

        Upon request and in accordance with customary U.S. practice, brokers, nominees and other similar record holders will be requested to forward proxy solicitation material to beneficial owners and, upon request and in accordance with customary practice, will be reimbursed by Macrocure for their out-of-pocket expenses.

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THE MERGER

        This section describes the merger and the other transactions contemplated by the merger agreement. The description in this section and elsewhere in this prospectus is qualified in its entirety by reference to the complete text of the merger agreement, a copy of which is attached as Annex A and is incorporated by reference into this prospectus. This summary does not purport to be complete and may not contain all of the information about the merger and the other transactions contemplated by the merger agreement that is important to you. You are encouraged to read the merger agreement carefully and in its entirety. This section is not intended to provide you with any factual information about Leap or Macrocure. Such information can be found elsewhere in this prospectus and in the public filings Macrocure makes with the Commission, as described in the section entitled "Where You Can Find More Information" beginning on Page 260 of this prospectus.

The Parties

    Macrocure Ltd.
    25 Hasivim Street
    Petach Tikva 4959383, Israel
    +972-54-565-6011

      Macrocure Ltd. was formed as a company in the State of Israel on January 14, 2008 and registered under No. 515506855 with the Israeli Registrar of Companies. Macrocure has operated since its inception as a biotechnology company focused on developing, manufacturing and commercializing novel cell therapy products to address unmet needs.

      Macrocure is subject to the provisions of the Companies Law. Macrocure's corporate headquarters are located at 25 Hasivim Street, Petach Tikva 4959383, Israel. Macrocure's telephone number is +972-54-565-6011 and its web site is located at www.macrocure.com (the information contained therein or linked thereto shall not be considered incorporated by reference in this prospectus). Macrocure's U.S. agent is Puglisi & Associates, located at 850 Library Avenue, Suite 204, Newark, Delaware 19711.

      In August 2014, Macrocure completed its initial public offering, and its ordinary shares began trading on The NASDAQ Global Market under the symbol "MCUR." Following the merger, Macrocure's ordinary shares will be delisted from the NASDAQ Global Market.

    Leap Therapeutics, Inc.
    47 Thorndike Street, Suite B1-1
    Cambridge, MA 02141
    617-714-0360

      Leap Therapeutics, Inc. was originally incorporated on January 3, 2011 as Dekkun Corporation, a Delaware corporation. Dekkun Corporation's name was changed to HealthCare Pharmaceuticals, Inc. in May 2014. On November 16, 2015, HealthCare Pharmaceuticals, Inc. changed its name to Leap Therapeutics, Inc.

      Leap is a biopharmaceutical company acquiring and developing novel therapeutics at the leading edge of cancer biology. Leap's approach is designed to target compelling tumor-promoting and immuno-oncology pathways to generate durable clinical benefit and enhanced outcomes for patients. Leap's programs are monoclonal antibodies that target key cellular pathways that enable cancer to grow and spread and specific mechanisms that activate the body's immune system to identify and attack cancer.

      The mailing address of Leap's principal executive office is 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141. Leap's telephone number is 617-714-0360. Leap's website address is

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      www.leaptx.com (the information contained therein or linked thereto shall not be considered incorporated by reference in this prospectus).

      Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

    M-CO Merger Sub Ltd.
    c/o Leap Therapeutics, Inc.
    47 Thorndike Street, Suite B1-1
    Cambridge, MA 02141
    617-714-0360

      M-CO Merger Sub Ltd. is a wholly owned subsidiary of Leap formed solely for the purpose of effectuating the merger described herein. Merger Sub was formed under the laws of the State of Israel and registered under No. 515506855 with the Israeli Registrar of Companies as a direct wholly owned subsidiary of Leap under the laws of Israel on August 15, 2016. Merger Sub owns no material assets and does not operate any business.

      The mailing address of Merger Sub's principal executive office is c/o Leap Therapeutics, Inc., 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141. Its telephone number is 617-714-0360.

      Upon consummation of the merger, Merger Sub will be merged with and into Macrocure and Macrocure will be the surviving corporation and be a wholly owned subsidiary of Leap. Merger Sub will then cease to exist.

General Information Concerning the Merger and Related Agreements

        Pursuant to the merger agreement, at the effective time of the merger, Merger Sub will be merged with and into Macrocure, with Macrocure surviving the merger and becoming a wholly owned subsidiary of Leap.

    Background of the Merger

        Leap's board of directors and executive management regularly review Leap's operating and strategic plans, both near-term and long-term, as well as potential partnerships in an effort to enhance stockholder value. This review includes considering debt and/or equity financing, mergers and acquisitions, and other strategic transactions, and Leap has engaged in discussions with numerous potential strategic partners, lenders and investors, including then current investors in Leap and potential new investors.

        Following Macrocure's announcements on August 19 and October 27, 2015 regarding the disappointing results of its Phase III clinical studies for CureXcell, its main product, Macrocure's board of directors and senior management commenced a review of strategic alternatives for Macrocure, while continuing to focus on managing and conserving its existing cash through cost reduction and restructuring initiatives. As part of that review, Macrocure's senior management team and board of directors regularly considered and evaluated options for enhancing shareholder value. Recognizing that in light of the failure of the CureXcell clinical trials, enhancing shareholder value as a stand-alone entity would be extremely challenging and uncertain, Macrocure's board of directors therefore actively engaged in pursuing a suitable business combination transaction with the goal of enhancing shareholder value.

        Accordingly, during the first quarter of 2016 Macrocure conducted a number of discussions with several potential targets concerning an acquisition of, combination with, or investment in, another

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company or technology, which, upon consummation, would provide Macrocure with new, active operations. As part of this initiative, Macrocure also began working with Raymond James & Associates, Inc. ("Raymond James") as its primary financial advisor to assist Macrocure in identifying potential targets.

        The following chronology sets forth a summary of the material events leading up to the execution of the merger agreement. In addition, throughout the chronology of developments described below, prior to and in between Macrocure's formal board meetings, the Chairman of the Board, Mr. Tomer Kariv, and the chief executive officer, Mr. Nissim Mashiach, updated Macrocure's directors on a frequent basis as to the nature and extent of such developments. During this time, Messrs. Mashiach and Kariv also continued to engage from time to time in discussions with third parties, although, ultimately, no transaction was identified that was felt to be as attractive to Macrocure and its shareholders as the proposed transaction with Leap.

        On or about February 2, 2016, Leap was contacted by Stuart Barich of Raymond James regarding Leap's possible interest in a combination of Leap and Macrocure. Promptly after that, and also on February 2, 2016, Leap's Chief Executive Officer, Christopher Mirabelli, and Chief Financial Officer, Douglas Onsi, held a conference call with Macrocure's Chairman of the Board, Tomer Kariv, and Chief Executive Officer, Nissim Mashiach, and with Mr. Barich to introduce the two companies to each other and to provide overviews of their business.

        On February 5, 2016, Leap and Macrocure signed a customary confidentiality agreement to allow for further discussions of their businesses and the potential for a transaction. Following the signing of the confidentiality agreement, Leap provided Macrocure with access to Leap's electronic data room for due diligence purposes.

        On February 9, 2016, Mr. Mashiach reported to Macrocure's board of directors his receipt of an indication from Leap of its interest in exploring a possible transaction with Macrocure.

        On February 12, 2016, Leap held a telephonic meeting of its board of directors in which Leap's management described potential financing alternatives and the potential Macrocure combination. The board of directors authorized the Leap management to continue discussions regarding potential terms.

        On February 24, 2016, Leap's Chief Operating Officer, Augustine Lawlor, and Mr. Onsi met with Mr. Kariv, Mr. Mashiach and Mr. Barich at Raymond James' office in New York City to provide additional information about the companies and discuss potential terms.

        Throughout the next four weeks, Dr. Mirabelli, Mr. Lawlor and Mr. Onsi continued discussions with Macrocure and provided information to support the diligence and review process being undertaken by Macrocure's management.

        At a meeting held on March 15, 2016, the Macrocure board of directors considered the indication of potential interest from Leap and thereafter authorized Macrocure's moving forward with preliminary diligence and an effort to structure and negotiate the terms of a potential transaction for further consideration by the board, following which Mr. Mashiach informed Leap of such authorization.

        Following such meeting, on March 17, 2016, Mr. Mashiach had a telephone call with Mr. Onsi in which he communicated Macrocure's interest in a potential transaction and legal, financial and diligence terms for consideration.

        On March 22, 2016, Macrocure formally engaged Raymond James as its financial advisor, based on Raymond James' qualifications, expertise and reputation in the capital markets, to support its efforts in pursuing a transaction with Leap and to provide an opinion with respect to the fairness, from a financial point of view, of the consideration to be received by Macrocure's shareholders in the potential transaction.

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        On March 24, 2016, Leap and Macrocure had an initial call with the legal teams of both companies, Morgan Lewis & Bockius LLP ("Morgan Lewis") for Leap and Meitar Liquornik Geva Leshem Tal ("Meitar") for Macrocure.

        On March 28, 2016, Macrocure provided Leap with an initial draft term sheet and with a draft exclusivity letter. On April 1, 2016, Leap responded to Macrocure's term sheet draft with comments.

        On April 6, 2016, Mr. Kariv, Mr. Mashiach and Dr. William Li, consultant to Macrocure, held an in-person due diligence meeting with members of the Leap management and operations team.

        Negotiations continued on the term sheet and exclusivity agreement for the next several weeks, and there was continued financial and legal due diligence performed by both sides, and business, clinical, scientific, regulatory and intellectual property due diligence performed by Macrocure and its advisers.

        On May 17, 2016, Dr. Mirabelli and Mr. Onsi updated Leap's board of directors at a meeting regarding the proposed business combination of Leap and Macrocure and the proposed term sheet. Leap's board of directors provided management with guidance as to acceptable terms to resolve the outstanding issues.

        On May 19, 2016, Mr. Kariv, Mr. Mashiach, Mr. Lawlor and Mr. Onsi held a conference call in which they agreed upon the outstanding economic issues on the proposed term sheet, bridging the divide between the parties by establishing a royalty right for Leap shareholders, increasing Macrocure's share of the post-closing outstanding equity and agreeing upon the size of a stock option pool for employees to be in place post-closing of the merger, and lastly by agreeing upon the treatment of stock options to be granted to key executives.

        Following that call, the parties proceeded to negotiate a revised non-binding written proposal for the merger. On May 31, 2016, Macrocure management reported to the Macrocure board of directors on the diligence undertaken to date and the Macrocure board of directors authorized management to execute the non-binding term sheet and the exclusivity agreement. Following the Macrocure board meeting, on June 1, 2016, Mr. Mashiach and Mr. Mirabelli executed the final version of the non-binding written proposal for the merger and each undertook on behalf of their respective companies to proceed to the negotiation of a definitive merger agreement and ancillary documents on the basis of the terms of such non-binding written proposal.

        Commencing with the execution of the non-binding written proposal for the merger, the parties began, in parallel, to conduct further due diligence, including a business presentation by Leap on June 6, 2016, and to negotiate the terms of the definitive agreements for the transaction. Morgan Lewis, U.S. counsel to Leap, Yigal Arnon & Co., Israeli counsel to Leap, Skadden, Arps, Slate, Meagher & Flom LLP ("Skadden"), US counsel to Macrocure, and Meitar, Israeli counsel to Macrocure, continued to negotiate the terms of the merger agreement in person, telephonically and via the exchange of drafts. There were frequent meetings, teleconferences, exchanges of information and negotiations as the parties sought to reach mutually agreeable terms.

        The extensive negotiations focused upon the merger agreement, voting agreements for Macrocure's and Leap's respective major shareholders, the royalty agreement and other ancillary documents. Some of the key issues discussed included, but were not limited to, the terms of the royalty right to be granted to the Leap stockholders, the wording for the defined term "Material Adverse Effect," the scope of the interim operating covenants, the size of the various termination fees which may be payable by Macrocure under certain circumstances, the respective rights of the parties to terminate following the "End Date," the scope of any obligations under the Macrocure voting agreements following termination of the merger agreement, and Macrocure's governance rights post-closing. During the negotiations, the members of each company's board of directors and senior management were continuously updated and consulted on the negotiations and remaining issues.

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        On August 8, 2016, the Macrocure board of directors held a telephonic meeting, in which representatives of Meitar and Skadden discussed with the board its fiduciary duties with respect to the proposed transaction. In addition, the board of directors reviewed with counsel detailed summaries of the draft merger agreement and ancillary documents, highlighting, among other things, the process for calculating the merger exchange ratio, the treatment of Macrocure's outstanding options, required consents, the anticipated timeline and process to closing, closing conditions, no-shop obligations, termination rights and termination fees. In addition, the Macrocure board of directors was apprised of the status of the negotiations of the definitive transaction agreements. At this meeting, it was observed that the principal agreement still to be negotiated was the royalty agreement, noting that the principal open issue was the term of the royalty right. After due consideration of the issue, the discussions thereof to date, and the board's belief that, irrespective of the term of the royalty right, the financial terms of the proposed transaction would be attractive from Macrocure's perspective, the board authorized management and the advisors to finalize the terms of the royalty agreement. In addition, Mr. Mashiach indicated that, while a thorough due diligence examination of Leap has previously been conducted, additional diligence was still being performed.

        In that same meeting, Mr. Stuart Barich of Raymond James presented to the Macrocure board of directors, a financial model based in part on certain assumptions and financial estimates shared by Leap and adjusted, among other things, for anticipated royalty payments pursuant to the proposed royalty agreement. See "Opinion of Macrocure's Financial Advisor—Certain Forecasts." He also explained the various methodologies employed by Raymond James for purposes of its analysis and the results obtained therefrom. Mr. Barich then reviewed Raymond James' internal procedures for preparing a fairness opinion, including its procedures for addressing potential conflicts of interest. It was also noted at the meeting that Raymond James may be asked to assist with future financings for the combined company, although no agreements were then in place.

        On August 16, 2016, the Leap board of directors held a telephonic meeting with Leap's legal advisors to review the finally negotiated major business terms of the Macrocure transaction. The directors acknowledged and discussed that they had met and discussed on numerous occasions, both formally and informally, the potential merits and risks to Leap and its stockholders of the merger, the chronology of events leading to the proposals to approve the merger, the negotiations with Macrocure with respect to the merger, the requirements for a bridge financing and closing of such financing to proceed with the merger, and the terms and conditions of such financing and the merger and related timeline. Leap's legal counsel summarized the terms and conditions of the proposed financing and merger, advised the directors on their fiduciary duties, and answered directors' questions. After discussion, Leap's board of directors (i) determined that the merger agreement and the transactions contemplated thereby, including the merger, are advisable and fair to, and in the best interests of, Leap and its stockholders, (ii) authorized and approved the merger, (iii) approved and adopted the merger agreement, (iv) resolved to recommend that the stockholders of Leap approve and adopt the merger agreement, and (v) approved certain other related matters, including the terms of the royalty agreement, registration rights agreement, employment agreements for Dr. Mirabelli, Mr. Lawlor and Mr. Onsi and stock option plans.

        On August 24, 2016, the Macrocure board of directors held a telephonic meeting at which management and counsel updated the board of directors about changes made to the proposed merger agreement and ancillary documents thereto since the date of the previous Macrocure board meeting.

        On August 29, 2016, the Macrocure board of directors held a telephonic meeting at which representatives of Meitar, Skadden, Raymond James, as well as Macrocure's chief executive officer and chief financial officer, were all present. The purpose of the meeting was to consider the final terms of the proposed merger transaction with Leap and to approve the merger agreement and all ancillary documents. Meitar then summarized the material terms of the proposed form of merger agreement and indicated that there were no material changes to the merger agreement and the ancillary documents

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since the last board meeting held on August 24, 2016. Mr. Mashiach also observed that since the last board meeting, he had a follow-up diligence call with the management of Leap to confirm the absence of any material developments. Mr. Barich then noted that, while the directors had received in advance of the meeting updated materials, there were no significant changes since the drafts previously circulated. Mr. Barich then indicated Raymond James' willingness to render its fairness opinion, as set forth in the draft letter circulated in advance of the meeting.

        After further consideration and discussion, the Macrocure board of directors then unanimously (with one director absent) (i) resolved, noting its extensive and thorough discussion of the factors relevant to this transaction during the course of its prior meetings, that the merger and the merger agreement were fair to, and in the best interests of, Macrocure's shareholders, and approved the merger agreement and the transactions contemplated thereunder, (ii) directed that the adoption of the merger agreement be submitted to a vote at a special general meeting of Macrocure's shareholders, and (iii) resolved to recommend to Macrocure's shareholders that they approve the merger, the merger agreement and all related matters to be brought before the shareholders at such special meeting. At the meeting, the board of directors also voted to approve and recommend that the shareholders of Macrocure approve various matters relating to the purchase of tail insurance covering actions taken by Macrocure's directors and officers on or prior to closing, the extension of the post-closing exercise period of the options held by certain existing employees and directors, and the amendment of outstanding Macrocure warrants, all of which were currently exercisable, to enable such warrants to survive the merger and become exercisable for common stock of Leap. It was noted by counsel that, while Mr. David Ben-Ami was not in attendance, Mr. Ben-Ami had expressed, at prior meetings, his support of the proposed transaction, and that, following the board meeting, Mr. Ben-Ami would be signing a voting agreement evidencing his support of the transaction.

    Recommendation of the Macrocure Board

        At a meeting held on August 29, 2016, the Macrocure board of directors unanimously (with one director absent) (i) determined that the merger agreement, the merger and the other transactions contemplated by the merger agreement are fair to and in the best interests of Macrocure and its shareholders, (ii) approved and declared it advisable that Macrocure enter into the merger agreement and (iii) adopted the merger agreement, the merger and the transactions contemplated thereby.

    Macrocure's Reasons for Approving the Merger

        At its August 29, 2016 meeting, the Macrocure board of directors unanimously (with one director absent) determined that the merger, the merger agreement and the other transactions contemplated by the merger agreement were fair to, and in the best interests of, Macrocure and its shareholders, and, considering the financial position of the merging companies, no reasonable concern existed that Macrocure would be unable to fulfill its obligations to its creditors existing as of immediately prior to the closing of the merger. Consequently, the Macrocure board of directors approved the merger, the merger agreement and the other transactions contemplated by the merger agreement and determined to recommend that the Macrocure shareholders approve the merger, the merger agreement and the other transactions contemplated by the merger agreement.

        In evaluating the merger, Macrocure's board of directors consulted with its management and legal, financial and other outside professional advisors and considered various information and factors in

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connection with the merger, including those material factors described below. Among the information and material factors considered by Macrocure's board of directors were the following:

Prospects of Risks to Macrocure as a Stand-Alone Company

    The prospective financial risks to Macrocure if it remains a stand-alone public entity, including risks and uncertainties with respect to:

    (i)
    not being able to generate any meaningful revenues in the future, in light of the failure of CureXcell, Macrocure's sole potential revenue-generating asset, to achieve target end-results in its clinical trials;

    (ii)
    the need to incur significant additional expenses to evaluate additional alternative potential strategic transactions, with no guarantee of success;

    (iii)
    the continuing need to incur significant ongoing compliance-related expenses in light of Macrocure's status as a public company that is required to report to the Commission under the Exchange Act; and

    (iv)
    as a result of the foregoing, the potential depletion of Macrocure's cash resources, to the point at which Macrocure would no longer be able to finance operations and may need to liquidate.

    The risk that if Macrocure remains a stand-alone entity and fails to consummate a transaction that provides active operations in the near future, NASDAQ could, at some point, determine that Macrocure is a "public shell company" (as defined under Commission rules) and, if it does, seek to delist Macrocure's ordinary shares.

    The potential adverse consequences to Macrocure's shareholders of a possible delisting by NASDAQ, including, but not limited to, the lack of a more established trading market for Macrocure's ordinary shares, which could result in reduced liquidity, decreased analyst coverage, and potentially greater difficulty in obtaining additional financing should that be required.

    The risk that Macrocure may not be successful in salvaging any remaining value from its proprietary cell activation technology.

Strategic Alternatives

        In the course of its deliberations, the Macrocure board of directors discussed potential alternatives to the transaction, including attempting to pursue another business combination transaction and/or secure a strategic partner other than Leap or pursuing a voluntary dissolution proceeding.

    The board noted that the limited ability of Macrocure to contribute technology or other assets related to operations (other than cash) to any strategic combination with another company, due to its prior business having been based exclusively on CureXcell, which failed to achieve its target end-results in clinical trials, limited the strategic alternatives available to Macrocure's board of directors.

    The board reviewed the issues likely to be involved with pursuing a voluntary liquidation and concluded those alternatives would not be in the best interests of the shareholders and would deny Macrocure shareholders the opportunity to realize significant value should a strategic partner be successful in gaining regulatory approval for, and thereafter commercializing, new drugs needed in the marketplace. Similarly, with respect to the merger, the board concluded that a voluntary liquidation would likely result in significantly less value to Macrocure's shareholders than the proposed transaction with Leap, should Leap be successful in further developing and bringing to market its current product candidates.

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    The board also took into account its prior unsuccessful efforts to find other strategic alternatives which, in the board's judgment, would be more attractive and that attempting to continue to look for other transactions would involve additional time and expense, without any assurance of greater success.

Financial Stability of Surviving Company; Potential Upside from Leap's Operations

    The prospective merger with Leap is conditioned (from Macrocure's perspective only) on Leap's existing stockholders investing an additional $10.0 million for shares of Leap Common Stock that will not be entitled to any preferential or contractual rights that are senior to those of Leap's other stockholders, including the Macrocure shareholders who will be receiving Leap common stock in the merger.

    The expectation that the surviving company from the merger will have a minimum of approximately $30.0 million in cash and no indebtedness, thereby enabling the combined company to pursue its operations and business plan for at least the next 12 months, including funding its ongoing clinical trials, and its attempts to obtain additional financing once additional test results are available.

    Macrocure's current equity holders will receive, in the aggregate as merger consideration, a significant percentage of the Leap common stock outstanding following the consummation of the merger and will therefore have a meaningful opportunity to participate in any possible growth and profits of the surviving company following the consummation of the transaction.

    Leap is an immuno-oncology company with a maturing pipeline of novel drug candidates designed to provide new and valuable treatment options for patients suffering from certain aggressive cancers. Leap's ongoing drug trials, if ultimately successful, should provide, in the board's judgment, good potential for the development of meaningful value.

    Leap will provide the combined company with an experienced management team, which has a track record relating to public and private companies and drug development success.

Raymond James Opinion; Liquidity of Consideration and Related Matters

    The merger agreement contains terms that were the product of arm's-length negotiations.

    The financial analysis reviewed by Raymond James, Macrocure's financial advisor, with Macrocure's board of directors, as well as the oral opinion of Raymond James rendered to Macrocure's board of directors on August 29, 2016 (which was subsequently confirmed in writing by delivery of Raymond James' written opinion addressed to the board of directors dated August 29, 2016), as to whether the merger consideration (consisting of shares of Leap common stock) to be received by the holders of ordinary shares in the merger pursuant to the merger agreement is fair to such holders from a financial point of view. See "The Merger—Opinion of Macrocure's Financial Advisor."

    The fact that, under the financial analyses presented by Raymond James, the percentage of the fully diluted shares to be received by Macrocure equityholders was favorable from a financial point of view.

    The fact that the shares of Leap common stock serving as merger consideration are being registered with the Commission under both the Securities Act and the Exchange Act and that Leap is applying for listing of such shares on NASDAQ, which, taken together, should provide the vast majority of Macrocure's shareholders with a continued opportunity for liquidity.

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Likelihood of Consummation

    The fact that no regulatory or third party approvals are required as a condition to consummation of the transaction, other than the approval for listing on NASDAQ of the Leap common stock.

    The fact that Macrocure shareholders owning, in the aggregate, approximately 51% of the issued and outstanding ordinary shares of Macrocure, have entered into voting agreements with Leap, pursuant to which such shareholders have expressed their support of the proposed transaction and have agreed to vote in favor of approval of the merger agreement, the merger and the other transactions contemplated by the merger agreement.

Other Terms

    Our board of directors took into account management's recommendation in favor of the merger.

Risks and Uncertainties

        Macrocure's board of directors also considered a number of uncertainties and risks in its deliberations concerning the Merger and the other transactions contemplated by the merger agreement, including the following:

    The inherent uncertainties associated with the preparation of forecasts for a business of this type.

    The fact that no assurance can be given regarding the success of the various drug trials to be undertaken post-closing, the costs and related timing associated with the completion of such trials, the ability of the combined company to obtain any required financing on satisfactory terms and/or the ability of the combined company to receive FDA or other required regulatory approvals, as well as the fact that the ultimate value of the merger consideration received may be affected by each of the foregoing.

    The fact that if Macrocure is unable to meet, at closing, the minimum $20.0 million net cash level, Leap could elect not to close.

    The fact that certain conditions to closing are beyond the control of Macrocure and the related risk that the proposed transaction might not be consummated, which could have an adverse effect on:

    (i)
    The market price of Macrocure's ordinary shares; and

    (ii)
    Macrocure's continued ability to retain its management members.

    The terms of the merger agreement, including (i) the restrictions (in particular, the non-solicitation restrictions) imposed on Macrocure between signing and closing which restrict Macrocure's ability to continue to explore other strategic opportunities absent receipt of an unsolicited bona fide proposal that meets certain tests set forth in the merger agreement and (ii) the $1.2 million termination fee and/or up to $750,000 of expense reimbursements that could become payable by Macrocure under certain circumstances.

    The fact that the foregoing provisions might have the effect of discouraging other persons potentially interested in combining with Macrocure from pursuing a transaction with Macrocure.

    The interests of certain of Macrocure's directors and officers in the merger, including certain arrangements that may provide certain benefits that are different from, and/or in addition to, those of Macrocure's other shareholders, as described under "Financial Interests of Macrocure's Directors and Executive Officers in the Merger."

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    The fact that the proposed transaction is expected to be a taxable transaction for Macrocure's U.S. shareholders, although any tax to be recognized would be subject to various factors. See the section entitled "U.S. Federal Income Tax Considerations."

    The fact that the proposed transaction might be taxable to Macrocure's Israeli shareholders upon consummation of the merger, absent receipt of an appropriate tax ruling. While the receipt of such a ruling is a condition to closing, the failure to close as a result of Macrocure's inability to receive such a ruling, could cause a termination fee of $1.6 million to become payable by Macrocure. See the sections entitled "The Merger—Fees and Expenses" and "Material Foreign Income Tax Consequences—Tax Rulings."

    The risk that the announcement of the proposed transaction can attract litigation.

    The risks described under the section above entitled, "Risk Factors."

        Macrocure's board of directors believed that, overall, the potential benefits of the Merger to Macrocure and its shareholders far outweighed the risks and uncertainties.

        The preceding discussion of the information and factors considered by Macrocure's board of directors is not intended to be exhaustive, but includes the material factors considered by Macrocure's board of directors. In view of the wide variety of factors considered by Macrocure's board of directors in connection with its evaluation of the merger, Macrocure's board of directors did not consider it practical to, nor did it attempt to, quantify, rank or otherwise assign relative weights to the different factors that it considered in reaching its decision. In addition, in considering the factors described above, individual members of Macrocure's board of directors may have given different weight to different factors. Macrocure's board of directors considered this information as a whole and overall considered the information and factors to be favorable to, and in support of, its determinations and recommendation.

        As described above, Macrocure's board of directors realized that there can be no assurance about future results, including results considered or expected as described in the factors listed above. The above explanation of the reasoning of Macrocure's board of directors contains information that is forward-looking in nature and, therefore, should be read in light of the factors discussed under the heading "Cautionary Statement Regarding Forward-Looking Statements."

Leap's Reasons for the Merger

        In approving and authorizing the merger agreement and the merger, the Leap board of directors considered a number of factors. Although the following discussion sets forth the material factors considered by the Leap board of directors in reaching its determination, it may not include all of the factors considered by the Leap board of directors. In light of the number and wide variety of factors considered in connection with its evaluation of the merger agreement and the merger, the Leap board of directors did not consider it practicable to, and did not attempt to, quantify or otherwise assign relative weights to the specific factors it considered in reaching its determination. The Leap board of directors viewed its position and determinations as being based on all of the information available and the factors presented to and considered by it. In addition, individual directors may have given different weight to different factors.

        In reaching its decision, the Leap board of directors consulted with Leap's management with respect to strategic and operational matters and with Leap's legal counsel with respect to the merger agreement and the transactions contemplated thereby.

        Among the factors considered by the Leap board of directors in its decision to approve the merger agreement were the following: (a) the judgment, advice and analysis of Leap's senior management and advisors with respect to the potential benefits of the merger, including Macrocure's available cash

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resources, as well as Macrocure's liabilities, based in part on the business, technical, financial due diligence investigations performed with respect to Macrocure; (b) Macrocure's status as a publicly traded company and the fact that following the merger, by issuing its shares to Macrocure's former shareholders, Leap could apply for listing to NASDAQ and would be a publicly traded company with potentially broader and more flexible financing opportunities; (c) historical and current information concerning Leap's business, including its financial performance and condition, operations, management and competitive position, current industry and economic conditions, and Leap's prospects if it was to remain an independent privately held company, including: (i) its need to obtain significant additional financing and the likely terms on which it would be able to obtain such financing; and (ii) the cost of drug development and the risk of adverse regulatory or clinical outcomes in clinical trials; (d) the status of Leap's drug candidates; (e) the general economic and market conditions, as they relate to Leap's ability to raise additional capital from new investors for the continued growth of Leap's business, the potential prospects for the combined company to raise additional capital, and the potential stock market performance of Leap as a publicly traded company; (f) the current conditions in the pharmaceutical and biotechnology marketplace and the positioning of Leap within that market after the merger; and (g) the terms of the merger agreement, including the merger consideration, as well as the parties' representations, warranties and covenants and the conditions to their respective obligations.

        In reaching its determination to approve the merger agreement and the merger, the members of the Leap board of directors identified and considered a number of the potentially beneficial aspects of the merger, including the following:

    the combined company's cash and cash equivalents and projected cash burn rate, in particular as they relate to the current plans of Leap for developing DKN-01 and TRX518 and the likelihood that Leap post-merger would possess sufficient financial resources to allow the management team to execute on the continued development of DKN-01 and TRX518;

    information concerning Leap's business, financial performance (both past and prospective) and its financial condition results of operation (both past and prospective), business and strategic objectives, as well as the risks of accomplishing those objectives;

    the fact that the merger will result in Leap becoming a publicly traded company, which would provide Leap stockholders with the possibility of liquidity for their shares;

    the fact that the existing Leap stockholders will be entitled, upon certain conditions, to receive payments based on the future net sales of DKN-01 and TRX518;

    that Leap post-merger will be led by an experienced senior management team and board of directors;

    the range of options available to the combined organization to access public equity markets to fund future capital needs or to complete business development transactions, which would likely be greater than the options available to Leap alone as a privately held company;

    the expected reaction and support of the transaction from the market, investment banks, Leap stockholders and Macrocure shareholders; and

    the terms of the merger agreement are reasonable, including the parties' representations, warranties and covenants, and the conditions to the parties' respective obligations.

        The members of the Leap board of directors also identified and considered the following material uncertainties and risks:

    the risk that the potential benefits of the merger might not be realized;

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    the reduction in the ability of Leap's current stockholders to realize the full long-term value of the successful execution of Leap's current strategy, and that former Macrocure shareholders will acquire a meaningful stake in Leap;

    the risk of diverting Leap management's attention from other strategic priorities to implement post-closing administration efforts relating to completing the wind-down of the Macrocure business or managing any unexpected Macrocure liabilities that may arise;

    the risk that future sales of Leap common stock by former Macrocure shareholders may cause the price of Leap common stock to fall;

    the risk that the merger may not be consummated, and that a more limited range of alternative strategic transactions would be available to Leap in that event; and

    the substantial expenses to be incurred in connection with the merger and related administrative challenges associated with combining the companies and fully winding down Macrocure.

        The Leap board of directors weighed the benefits, advantages and opportunities of a potential transaction against the negative factors described above, including the possible diversion of management attention for an extended period of time. The Leap board of directors realized that there can be no assurance about future results, including results expected or considered in the factors listed above. However, the Leap board of directors concluded that the potential benefits significantly outweighed the potential risks of completing the merger.

        After taking into account these and other factors, the Leap board of directors approved and authorized the merger agreement and the transactions contemplated thereby, including the merger.

Related Transactions and Agreements

    Equity Investment

        By the terms of the merger agreement and their respective voting agreements, certain current stockholders of Leap, specifically, HealthCare Partners VIII, L.P., HealthCare Ventures IX, L.P. and HealthCare Ventures Strategic Fund, L.P., or their designees, have committed to invest approximately $10.0 million into Leap by purchase of common stock of Leap immediately prior to the consummation of the merger in order to provide additional liquidity and working capital to Leap following the consummation of the merger. Absent such investment and the adoption of Leap's 2016 Equity Incentive Plan, and immediately following the merger, approximately 65% of the outstanding Leap common stock would be held by shareholders and option holders that were holders of Leap common stock and stock options immediately prior to the effectiveness of the merger and approximately 35% of the Leap common stock would be held by shareholders, option holders and warrant holders that were holders of Macrocure ordinary shares, stock options and warrants immediately prior to the effectiveness of the merger (other than holders of the out-of-the-money options).

        The foregoing percentage ownership assumes the exercise of all options of Macrocure and Leap outstanding as of the effective time of the merger (other than the out-of-the-money options). The parties have agreed that the $10.0 million investment will dilute both the former Leap equityholders and former Macrocure equityholders and as a result, immediately following such investment, but not giving effect to the adoption of Leap's 2016 Equity Incentive Plan, and following the merger, approximately 68.2% of the outstanding Leap common stock would be held by stockholders and option holders that were holders of Leap common stock and stock options immediately prior to the effectiveness of the merger and approximately 31.8% of the outstanding Leap common stock would be held by shareholders, optionholders and warrantholders that were holders of Macrocure ordinary shares, stock options and warrants immediately prior to the effectiveness of the merger (other than holders of the out-of-the-money options).

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    Voting Agreements

        In connection with the execution of the merger agreement, Ze'ev Bronfeld, a director of Macrocure, David Ben Ami, a director of Macrocure, Ranan Groban, a director of Macrocure, Vaizra Ventures, Viatcheslav Mirilasvili, Shlomo Kalish,, Pontifax (Israel) II—Individual Investors L.P., Pontifax (Israel) II L.P., Pontifax (Cayman) II L.P., and Nissim Mashiach, the chief executive officer of Macrocure, each entered into a voting agreement with Leap under which each such equityholder has agreed to vote in favor of the merger and against any alternative acquisition proposal, agreement or transaction. As of August 29, 2016, these entities collectively beneficially own or control approximately 54.28% of the voting power of Macrocure on an as-converted to common stock basis. These voting agreements grant Leap irrevocable proxies to vote any Macrocure ordinary shares over which each such equityholder has voting power in favor of each of the Macrocure proposals described elsewhere in this prospectus and against any alternative acquisition proposal, agreement or transaction.

        In connection with the execution of the merger agreement, HealthCare Partners VIII, L.P., HealthCare Ventures IX, L.P., HealthCare Ventures Strategic Fund, L.P. and Eli Lilly and Company, who collectively beneficially owned or control 100% of Leap's outstanding common stock as of August 29, 2016, the date that each entered into a voting agreement with Macrocure under which each such stockholder has agreed to (i) vote in favor of the Leap proposals that relate to the merger described elsewhere in this prospectus and against any alternative acquisition proposal, agreement or transaction and (ii) take certain actions necessary to approve and implement certain other requirements of Leap upon which Macrocure's obligation to consummate the transactions contemplated in the merger agreement is conditioned. Each of these voting agreements grants Macrocure irrevocable proxies to vote any shares of Leap common stock over which each such stockholder has voting power in favor of (i) each of the Leap proposals described elsewhere in this prospectus and against any alternative acquisition proposal, agreement or transaction and (ii) each such other approval necessary to satisfy certain other requirements of Leap upon which Macrocure's obligation to consummate the transactions contemplated in the merger agreement is conditioned.

        Each equityholder executing a voting agreement has made representations and warranties to Macrocure and Leap, as applicable, regarding ownership and unencumbered title to the securities thereto, each such equityholder's power and authority to execute the voting agreement, and due execution and enforceability of the voting agreement. Unless otherwise waived, all of these voting agreements generally prohibit the sale, assignment, transfer or other disposition by each equityholder of its securities, as applicable, or the entrance into an agreement or commitment to do any of the foregoing, except for transfers by will or by operation of law, in which case the voting agreement shall bind the transferee. Each equityholder executing a voting agreement has also waived its statutory appraisal rights in connection with the merger.

        The voting agreements will terminate upon the earlier of the effective time of the merger, termination of the merger agreement in accordance with its terms or upon mutual written consent of such equityholder and either Macrocure or Leap, as applicable; provided that if the voting agreements entered into between each of the Macrocure equityholders and Leap should terminate due to the termination of the merger agreement under certain of the termination provisions therein, certain provisions of the voting agreement, including the Macrocure equityholders' obligation to vote against any alternative acquisition proposal, shall continue for six (6) months after the termination of the voting agreement.

    Royalty Agreement

        In connection with the transactions contemplated by the merger agreement, Leap will declare a special distribution of certain royalty rights to each of its holders of common stock outstanding immediately prior to the effective time of the merger. The royalty rights will be set forth in a royalty

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agreement, referred to herein as the Royalty Agreement, by and between Leap and a special purpose vehicle formed by those holders of Leap's common stock prior to the merger, specifically, HealthCare Partners VIII, L.P., HealthCare Ventures IX, L.P., HealthCare Ventures Strategic Fund, L.P. and Eli Lilly and Company. These holders collectively beneficially own or control 100% of Leap's outstanding common stock as of the date of this prospectus.

        Pursuant to the Royalty Agreement, Leap will pay to the special purpose vehicle (i) 5% of Leap's net sales of products incorporating its TRX518 compound and (ii) 2% of Leap's net sales of products incorporating its DKN-01 compound. Net sales will be calculated as the gross amount invoiced by Leap, its affiliates, assignees or sublicensees to a third party, but shall be reduced by any discounts, refunds, rebates, product returns, bad debts, sales taxes, VAT and other similar taxes. The calculation of the gross amount invoiced shall also be discounted in the event that Leap's product is sold as part of a combination product. Royalties will be payable by Leap to the special purpose vehicle every calendar quarter. Among other customary terms for licensing transactions of this type, the special purpose vehicle will have the right no more than once a year to have an independent certified public accountant audit Leap's records to determine the accuracy of royalty payments received. The Royalty Agreement will have an indefinite term, and neither Leap nor the special purpose vehicle will have the right to terminate.

        Holders of Macrocure ordinary shares will not be participating in the distribution and will receive no payments under the Royalty Agreement, nor will they participate or have any interest in the special purposes vehicle or right to any royalties payable by Leap.

    Registration Rights Agreement

        In connection with the transactions contemplated by the merger agreement, Leap will be entering into a Registration Rights Agreement with each of its holders of common stock outstanding immediately prior to the effective time of the merger. In addition to the former holders of Leap's common stock, certain larger holders of Leap's common stock following the merger (who were among the largest holders of Macrocure ordinary shares prior to the merger) will become parties to the Registration Right Agreement. Pursuant to the terms of the Registration Rights Agreement, the Amended and Restated Shareholders' Agreement between Leap and its holders of common stock, dated as of December 10, 2015, will terminate.

        Under Leap's Registration Rights Agreement, certain holders of registrable shares can demand that Leap file a registration statement or request that their shares be included on a registration statement that Leap is otherwise filing, in either case, registering the resale of their shares of Leap common stock. These registration rights are subject to conditions and limitations, including the right, in certain circumstances, of the underwriters of an offering to limit the number of shares included in such registration and such holders' right, in certain circumstances, not to effect a requested registration on Form S-3 if such registration is in connection with any underwritten offering or proposed underwritten public offering.

Merger Consideration

        At the effective time of the merger, other than (i) shares that, immediately prior to the effective time of the merger, are considered dormant shares (or menayot redumot) under the Israeli Companies Law and (ii) each Macrocure ordinary share owned, directly or indirectly, by Leap or Merger Sub, each Macrocure ordinary share issued and outstanding immediately prior to the effective time of the merger will be converted automatically into the right to receive, a number of shares of Leap common stock equal to the quotient obtained by dividing (i) the product of (a) 0.35 multiplied by the quotient obtained by dividing (I) the aggregate number of shares of Leap common stock outstanding after giving effect to the Pre-Closing Leap Share Conversion, the Recap and the assumed exercise of all

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outstanding stock options by (II) 0.65, by (ii) the aggregate number of Macrocure ordinary shares, including those issuable upon the exercise of Macrocure warrants, Macrocure options (but not including any out-of-the-money options) and any other awards under Macrocure's stock option plans, in each case, outstanding immediately prior to the consummation of the merger. This exchange shall be calculated prior to giving effect to (i) a contemplated $10.0 million equity investment into Leap committed by certain affiliates of Leap immediately prior to the consummation of the merger and (ii) the adoption of Leap's 2016 Equity Incentive Plan, representing a number of shares of Leap common stock that, together with the out-of-the-money options outstanding at the effective time of the merger, represents 8% of Leap's fully diluted capitalization. At the effective time of the merger, each Macrocure ordinary share owned, directly or indirectly, by Leap or Merger Sub will be cancelled and retired and no consideration will be paid for such shares.

Pre-Closing Leap Share Conversion and Recapitalization

        Pursuant to the terms of the merger agreement, immediately prior to the consummation of the merger, Leap's Charter and Bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, of this prospectus. Immediately prior to the filing of the New Leap Charter, each issued and outstanding share of Leap preferred stock and each outstanding Leap convertible promissory note will convert into shares of Leap common stock. In connection with the amendment of the Leap Charter, each share of Leap common stock issued and outstanding immediately prior to the effective time of the merger will be reclassified and changed into a number of shares of Leap common stock at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock. The equity investment will occur immediately prior to the effective time of the merger, but after the Pre-Closing Leap Share Conversion and the Recap.

        No fractional shares of Leap common stock will be issued in connection with the Pre-Closing Leap Share Conversion, and each holder of shares of Leap common stock converted pursuant to the Pre-Closing Leap Share Conversion who would otherwise have been entitled to receive a fraction of a share of Leap common stock will receive cash in lieu thereof in accordance with the New Leap Charter.

Opinion of Macrocure's Financial Advisor

    Summary of Raymond James' Financial Analysis

        Macrocure retained Raymond James as its financial advisor on March 22, 2016. Pursuant to that engagement, the Board requested that Raymond James evaluate the fairness, from a financial point of view, to the holders of Macrocure ordinary shares of the approximately 32.0% of the outstanding shares (after giving effect to the adoption of Leap's 2016 Equity Incentive Plan, but not giving effect to a contemplated $10.0 million equity investment into Leap immediately prior to the consummation of the merger committed by certain affiliates of HealthCare Ventures) of Leap common stock to be received by such holders (including, for these purposes, warrantholders and optionholders (excluding holders of the out-of-the-money options)) pursuant to the merger agreement.

        At the Macrocure board of director's August 29, 2016 meeting, representatives of Raymond James rendered its oral opinion, which was subsequently confirmed by delivery of a written opinion to the Board, dated August 29, 2016, as to the fairness, as of such date, from a financial point of view, to the holders of Macrocure ordinary shares of the merger consideration to be paid by Leap to the holders of the Macrocure ordinary shares. Additionally, as indicated above, at Macrocure's direction and with Macrocure's consent, Raymond James did not consider the terms of the distributed royalty rights in forming its opinion other than to the extent the ongoing costs of such royalty rights to Leap are incorporated into the projections that were utilized in the performance of Raymond James' discounted cash flow analysis.

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        The full text of the written opinion of Raymond James is attached as Annex B to this prospectus. The summary of the opinion of Raymond James set forth in this document is qualified in its entirety by reference to the full text of such written opinion. Holders of Macrocure ordinary shares are urged to read this opinion in its entirety.

        Raymond James provided its opinion for the information of the Macrocure board (solely in its capacity as such) in connection with, and for purposes of, its consideration of the merger and its opinion only addresses whether the merger consideration to be received by the holders of Macrocure ordinary shares in the merger pursuant to the merger agreement was fair, from a financial point of view, to such holders. The opinion of Raymond James does not address any other term or aspect of the merger agreement or the merger contemplated thereby. The Raymond James opinion does not constitute a recommendation to the board or to any holder of Macrocure ordinary shares as to how the board, such shareholder or any other person should vote or otherwise act with respect to the merger or any other matter.

        In connection with its review of the proposed merger and the preparation of its opinion, Raymond James, among other things:

    reviewed the financial terms and conditions as stated in the draft of the merger agreement, dated as of August 25, 2016, the most recent draft made available to Raymond James;

    reviewed certain information related to the future operations, financial condition and prospects, of Leap made available to Raymond James by Macrocure, including, but not limited to, financial projections prepared by the management of Leap, as approved for Raymond James' use by management of Macrocure and the Macrocure board (the "Projections");

    reviewed financial, operating and other information regarding Leap and the industry in which it operates;

    reviewed certain financial and stock market data of selected public companies that Raymond James deemed to be relevant;

    reviewed certain publicly available information concerning certain financial terms of selected business combinations and initial public offerings Raymond James deemed relevant;

    performed a discounted cash flow analysis with respect to Leap based upon the Projections;

    reviewed the current and recent market prices and trading volume for Macrocure ordinary shares;

    conducted such other financial studies, analyses and inquiries, and considered such other information and factors, as Raymond James deemed appropriate; and

    discussed with members of the senior management of Macrocure certain information relating to the aforementioned and any other matters which Raymond James deemed relevant to its inquiry.

        With Macrocure's consent, Raymond James assumed and relied upon the accuracy and completeness of all information supplied by or on behalf of Macrocure and Leap, or otherwise reviewed by or discussed with Raymond James, and Raymond James did not undertake any duty or responsibility to, nor did Raymond James, independently verify any of such information. Raymond James did not make or obtain an independent appraisal of the assets or liabilities (contingent or otherwise) of Macrocure or Leap, nor was Raymond James furnished with any such evaluations or appraisals. With respect to the Projections and any other information and data provided to or otherwise reviewed by or discussed with Raymond James, Raymond James, with Macrocure's consent, assumed that the Projections and such other information and data were reasonably prepared in good faith on bases reflecting the best currently available estimates and judgments of management of Leap or the party preparing such other information or data and that formed a reasonable basis upon which

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Raymond James could form its opinion. Raymond James relied upon Macrocure to advise Raymond James promptly if any information previously provided became inaccurate or was required to be updated during the period of its review and has assumed that all such information is complete and accurate in all material respects. Raymond James expressed no opinion with respect to the Projections or the assumptions on which they were based and does not, in any respect, assume any responsibility for the accuracy thereof. Furthermore, at Macrocure's request and with Macrocure's consent, Raymond James conducted certain analyses utilizing probability adjusted financial forecasts of Leap prepared by management of Leap which take into account the probability and timing of the occurrence of cash flows from potential products of Leap. All such projected financial information is based upon numerous variables and assumptions and actual results could vary significantly from those set forth in such projected financial information. Raymond James has relied upon, without independent verification, the assessment of management of Leap, as provided to Raymond James and approved by Macrocure, as to the existing products and services of Leap and the viability of, and risks associated with, the future products and services of Leap (including without limitation, the development, testing and marketing of such products and services, the receipt of all necessary governmental and other regulatory approvals for the development, testing and marketing thereof, and the life and enforceability of all relevant patents and other intellectual and other property rights associated with such products and services).

        Raymond James relied upon and assumed, without independent verification, that the final form of the merger agreement would be substantially similar to the draft merger agreement reviewed by Raymond James in all respects material to its analysis or opinion, and that the merger would be consummated in accordance with the terms of the merger agreement without waiver of or amendment to any of the conditions thereto. Furthermore, Raymond James assumed, in all respects material to its analysis, that the representations and warranties of each party contained in the merger agreement were true and correct and that each party will perform all of the covenants and agreements required to be performed by it under the merger agreement without being waived. Raymond James also relied upon and assumed, without independent verification, that (i) the merger would be consummated in a manner that complies in all respects with all applicable international, federal and state statutes, rules and regulations, and (ii) all governmental, regulatory or other consents and approvals necessary for the consummation of the merger would be obtained and that no delay, limitations, restrictions or conditions would be imposed or amendments, modifications or waivers made that would have an effect on the merger or Leap that would be material to its analysis or opinion. Raymond James has, with Macrocure's consent, further assumed that the adjustment in the merger agreement for the final net cash amount will not result in any adjustment to the merger consideration that is material to Raymond James' analysis. Macrocure informed Raymond James, and Raymond James has assumed, that the merger and the transactions related thereto contemplated by the Agreement will be treated as a taxable transaction for U.S. federal income tax purposes for the holders of Macrocure ordinary shares located in the United States.

        Raymond James expressed no opinion as to the underlying business decision to effect the merger, the structure or tax consequences of the merger, or the availability or advisability of any alternatives to the merger. Raymond James did not recommend any specific amount of consideration for the merger. Raymond James's opinion does not opine as to the trading range of Leap common stock following the merger, which may vary depending on numerous factors that generally impact the price of securities or on the financial condition of Leap at the time. The Raymond James opinion is limited to the fairness, from a financial point of view, of the merger consideration to be received by the holders of Macrocure ordinary shares. Subsequent developments may affect the conclusions expressed in Raymond James' opinion if such opinion had been rendered at a later date and Raymond James disclaims any obligation to advise any person of any change in any manner affecting its opinion that may come to its attention after the date of the opinion. Raymond James expressed no opinion with respect to any other reasons (legal, business, or otherwise) that may support the decision of the board to approve or consummate

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the merger. Furthermore, no opinion, counsel or interpretation was intended by Raymond James on matters that require legal, accounting or tax advice. Raymond James assumed that such opinions, counsel or interpretations had been or would be obtained from appropriate professional sources. Furthermore, Raymond James relied, with the consent of Macrocure, on the fact that Macrocure was assisted by legal, accounting and tax advisors, and, with the consent of Macrocure relied upon and assumed the accuracy and completeness of the assessments by Macrocure and its advisors, as to all legal, accounting and tax matters with respect to Macrocure and the merger.

        In formulating its opinion, Raymond James considered only the approximately 32.0% of Leap common stock to be received by the holders of Macrocure ordinary shares (including, for these purposes, warrant holders and certain holders of options), and Raymond James did not consider, and its opinion did not address, the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of any party to the merger, or such class of persons, in connection with the merger whether relative to the approximately 32.0% of Leap common stock or otherwise. Raymond James was not requested to opine as to, and its opinion did not express an opinion as to or otherwise address, among other things: (1) the fairness of the merger to the holders of any class of securities, creditors or other constituencies of Macrocure, or to any other party, except and only to the extent expressly set forth in the last sentence of its opinion or (2) the fairness of the merger to any one class or group of Macrocure's or any other party's security holders or other constituents vis-à-vis any other class or group of Macrocure's or such other party's security holders or other constituents (including, without limitation, the allocation of any consideration to be received in the merger amongst or within such classes or groups of security holders or other constituents). Raymond James expressed no opinion as to the impact of the merger on the solvency or viability of Macrocure or Leap or the ability of Macrocure or Leap to pay their respective obligations when they come due. Raymond James did not consider any potential legislative or regulatory changes currently being considered or recently enacted by the Commission, or any other regulatory bodies, including, but not limited to, any regulatory bodies in the State of Israel, or any changes in accounting methods or generally accepted accounting principles that may be adopted by the Commission or the Financial Accounting Standards Board.

    Material Financial Analyses

        The following summarizes the material financial analyses reviewed by Raymond James with the Macrocure board at its August 29, 2016 meeting, which material was considered by Raymond James in rendering its opinion. No company or transaction used in the analyses described below is identical or directly comparable to Macrocure, Leap or the merger. Accordingly, an analysis of the results of such a comparison is not purely mathematical, but instead involves complex considerations and judgements concerning differences in historical and projected financial and operating characteristics of the Selected Companies and other factors that could affect the public trading value of such companies and Leap to which they are being compared.

    Selected Companies Analysis.

        Raymond James reviewed the equity values of 13 publicly-traded companies developing oncology products (the "Selected Companies") that it deemed relevant, including:

    BeiGene, Ltd.

    Hutchison China MediTech

    Loxo Oncology, Inc.

    Adaptimmune Therapeutics plc

    Syros Pharmaceuticals, Inc.

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    OncoMed Pharmaceuticals, Inc.

    Corvus Pharmaceuticals, Inc.

    Syndax Pharmaceuticals, Inc.

    Ignyta, Inc.

    Merus B.V.

    Vascular Biogenics Ltd.

    TRACON Pharmaceuticals, Inc.

    Immune Design Corp.

        Raymond James reviewed the mean, median, 25 th  percentile and 75 th  percentile of equity values of the Selected Companies to derive a range of potential values for Leap. Raymond James then used this range of potential values for Leap to calculate the implied ownership that would be attributable to the holders of Macrocure ordinary shares based on a Macrocure equity value of $23.8 million, as calculated using a ten-day average share price of $1.40/share as of August 25, 2016. Raymond James then compared these implied ownership percentages to the merger consideration whereby approximately 31.8% of Leap common stock will be held by the holders of the Macrocure ordinary shares. The results of the Selected Companies analysis are summarized below:

GRAPHIC

    Selected Initial Public Offerings Analysis

        Raymond James reviewed the implied pre-money equity value at initial public offering ("IPO") of 23 companies that have completed IPOs since 2014 and that were developing oncology products at the time of their IPO (the "Selected IPO Companies"). "Pre-money equity value" means the equity valuation of each such company implied by the offering price of such company's shares in its IPO, excluding the proceeds of the IPO. The Selected IPO Companies used in the analysis were:

    Syros Pharmaceuticals, Inc.

    Merus B.V.

    Oncobiologics, Inc.

    Corvus Pharmaceuticals, Inc.

    Hutchison China MediTech Ltd.

    Syndax Pharmaceuticals, Inc.

    BeiGene, Ltd.

    Advanced Accelerator Applications S.A.

    Kura Oncology, Inc.

    Mirna Therapeutics, Inc.

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    NantKwest, Inc.

    ProNAi Therapeutics, Inc.

    Adaptimmune Therapeutics plc

    TRACON Pharmaceuticals, Inc.

    Juno Therapeutics Inc.

    Calithera Biosciences, Inc.

    Tokai Pharmaceuticals, Inc.

    Affimed Therapeutics AG

    Loxo Oncology, Inc.

    Immune Design Corp.

    Kite Pharma, Inc.

    Cerulean Pharma Inc.

    Ignyta, Inc.

        Raymond James reviewed the mean, median, 25 th  percentile and 75 th  percentile of implied pre-money equity values of the Selected IPO Companies to derive a range of potential values for Leap. Raymond James then used this range of potential values for Leap to calculate the implied ownership that would be attributable to the holders of Macrocure ordinary shares based on a Macrocure equity value of $23.8 million as calculated using a ten day average share price of $1.40/share as of August 25, 2016. Raymond James then compared these implied ownership percentages to the merger consideration whereby approximately 32.0% of Leap common stock will be held by the holders of the Macrocure ordinary shares. The results of the Selected IPO Companies analysis are summarized below:

GRAPHIC

    Selected Transaction Analysis

        Raymond James analyzed publicly available information relating to selected acquisitions of private companies developing oncology products from 2014 to August 25, 2016 (the "Selected Transactions"). Acquisitions with total transaction value below $20 million and transactions for a minority stake were excluded. Minority stake is defined as the acquirer owning less than or equal to 49% of the target

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company. For each transaction, Raymond James reviewed the implied total enterprise value of the target company. The Selected Transactions used in the analysis included:

GRAPHIC

        Raymond James reviewed the mean, median, 25 th  percentile and 75 th  percentile of implied total enterprise values of the Selected Transactions with the contingent value rights ("CVR") included and implied total enterprise values excluding the CVR to derive a range of potential values for Leap. Raymond James then used this range of potential values for Leap to calculate the implied ownership that would be attributable to the holders of Macrocure ordinary shares based on a Macrocure equity value of $23.8 million as calculated using a ten-day average share price of $1.40/share as of August 25, 2016. Raymond James then compared these implied ownership percentages to the merger consideration whereby approximately 32.0% of Leap common stock will be held by the holders of the Macrocure ordinary shares. The results of the Selected Transactions analysis are summarized below:

GRAPHIC

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    Discounted Cash Flow Analysis

        Raymond James estimated a range of equity values for Leap based upon the present value of Leap's estimated unlevered free cash flows for fiscal years ended December 31, 2017 through December 31, 2031, in each case with risk adjustments as provided by and approved for Raymond James use by Macrocure. In performing this discounted cash flow analysis, Raymond James utilized discount rates ranging from 13.0% to 15.0%, which were selected based on the capital asset pricing model and the estimated weighted average cost of capital of the Selected Companies. This discounted cash flow analysis assumed that Leap has no terminal value. This discounted cash flow analysis was based upon certain assumptions described below regarding the Projections and discussions held with the management of Leap and Macrocure.

        Raymond James reviewed the range of implied equity values derived in the discounted cash flow analysis to derive a range of potential values for Leap. Raymond James then used this range of potential values for Leap to calculate the implied ownership that would be attributable to the holders of Macrocure ordinary shares based on a Macrocure equity value of $23.8 million as calculated using a ten day average share price of $1.40/share as of August 25, 2016. Raymond James then compared these implied ownership percentages to the merger consideration whereby approximately 32.0% of Leap common stock will be held by the holders of the Macrocure ordinary shares. The results of the discounted cash flow analysis are summarized below:

GRAPHIC

    Additional Considerations

        The preparation of a fairness opinion is a complex process and is not susceptible to a partial analysis or summary description. Raymond James believes that its analyses must be considered as a whole and that selecting portions of its analyses, without considering the analyses taken as a whole, would create an incomplete view of the process underlying its opinion. In addition, Raymond James considered the results of all such analyses and did not assign relative weights to any of the analyses, but rather made qualitative judgments as to significance and relevance of each analysis and factor, so the ranges of valuations resulting from any particular analysis described above should not be taken to be the view of Raymond James as to the actual value of Leap or Macrocure.

        In performing its analyses, Raymond James made numerous assumptions with respect to industry performance, general business, economic and regulatory conditions and other matters, many of which are beyond the control of Macrocure. The analyses performed by Raymond James are not necessarily indicative of actual values, trading values or actual future results which might be achieved, all of which may be significantly more or less favorable than suggested by such analyses. Such analyses were provided to the Board (solely in its capacity as such) and were prepared solely as part of the analysis of Raymond James of the fairness, from a financial point of view, to the holders of Macrocure ordinary shares of the approximately 32.0% of Leap common stock to be received by such holders in connection with the proposed merger pursuant to the merger agreement. The analyses do not purport to be appraisals or to reflect the prices at which companies may actually be sold, and such estimates are inherently subject to uncertainty. The opinion of Raymond James was one of a number of factors taken into account by the board in making its determination to approve the merger. Neither Raymond James' opinion nor the analyses described above should be viewed as the only factor considered by the board or Macrocure management's views with respect to Macrocure, Leap or the merger. Raymond James

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provided advice to Macrocure with respect to the proposed transaction. Raymond James did not, however, recommend any specific amount of consideration to the Board or that any specific percentage of Leap common stock constituted the only appropriate consideration for the merger. Macrocure placed no limits on the scope of the analysis performed, or opinion expressed, by Raymond James.

        The Raymond James opinion was necessarily based upon market, economic, financial and other circumstances and conditions existing and disclosed to it on August 29, 2016, and any material change in such circumstances and conditions may affect the opinion of Raymond James, but Raymond James does not have any obligation to update, revise or reaffirm that opinion. Raymond James relied upon and assumed, without independent verification, that there had been no change in the business, assets, liabilities, financial condition, results of operations, cash flows or prospects of Leap since the respective dates of the most recent financial statements and other information, financial or otherwise, provided to Raymond James that would be material to its analyses or its opinion, and that there was no information or any facts that would make any of the information reviewed by Raymond James incomplete or misleading in any material respect.

        During the two years preceding the date of Raymond James' written opinion, there were no material relationships or that are mutually understood to be contemplated in which any compensation was received or is intended to be received as a result of the relationship between Raymond James and any party to the merger, other than the March 22, 2016 engagement letter between Raymond James and Macrocure entered into in connection with the merger.

        For services rendered in connection with the delivery of its opinion, Macrocure paid Raymond James a customary investment banking fee upon delivery of its opinion. Macrocure will also pay Raymond James a customary fee for advisory services in connection with the merger, which is contingent upon the closing of the merger. Macrocure also agreed to reimburse Raymond James for its expenses incurred in connection with its services, including the fees and expenses of its counsel, and will indemnify Raymond James against certain liabilities arising out of its engagement.

        Raymond James, as part of its investment banking business, is continually engaged in the valuation of businesses and their securities in connection with mergers and acquisitions, negotiated underwritings, secondary distributions of listed and unlisted securities, private placements and valuations for corporate and other purposes. In the ordinary course of its business, Raymond James may trade in the securities of Macrocure or Leap for its own account or for the accounts of its customers and, accordingly, may at any time hold a long or short position in such securities. Raymond James may provide investment banking, financial advisory and other financial services to Macrocure, Leap or other participants in the merger in the future, for which Raymond James may receive compensation.

    Certain Forecasts

        Leap, as a matter of course, does not prepare or make public long-term projections as to future revenues, earnings or other results due to, among other reasons, the uncertainties of the new drug development, approval and commercialization processes, as well as other uncertainties associated with underlying assumptions and estimates.

        Certain assumptions and financial estimates were prepared by the management of Leap and shared with Raymond James, which were thereafter adjusted and incorporated into the projections (the "Projections") utilized by Raymond James in connection with Raymond James' evaluation of the fairness of the merger consideration from a financial point of view to the holders of Macrocure ordinary shares. Raymond James was authorized by Macrocure to use and rely upon such Projections for purposes of its analyses without independent verification. The inclusion of information about the Projections in this prospectus, however, should not be regarded as an indication that any of Leap, Macrocure or any recipient of this information considered, or now considers, the Projections to be predictive of actual future results.

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        The Projections rely on numerous estimates and assumptions including, among others: launch dates of 2021 and 2023 for DKN-01 and TRX518, respectively; annual gross revenues at peak of $1,760 million for DKN-01 in 2028 and $2,300 million for TRX518 in 2029; royalties being paid to third parties in accordance with existing agreements; assumed cost of goods sold equal to 5.0% of total net revenues; a tax rate of 40.0% prior to giving effect to any utilization of available net-operating-loss cost carry forwards; accumulated operating expenses pre-launch of either drug of $275 million; and assumed operating expenses post-launch of both drugs: selling and marketing expense of $35 million each year, maintenance R&D equal to 3.0% of net revenue and G&A equal to $10 million each year. The Projections also reflect the royalties to be paid to Leap shareholders at the rates set forth in the royalty agreement; and the assumed cumulative probabilities of ultimately receiving regulatory approvals based on published historical success rates for oncology clinical trials, as well as discussions with Macrocure management, of 23.5% for DKN-01 and 18.0% for TRX518 for purpose of risk adjusting the amount of total net revenue, cost of goods sold and operating expenses.

        The Projections are subjective in many respects and thus subject to interpretation. While presented with numeric specificity, the Projections reflect numerous estimates and assumptions that are inherently uncertain with respect to general business, economic, market and financial conditions and matters specific to Leap, including the revenues to be received following FDA approval, the likelihood of receiving FDA approval, and the other factors described or referenced under "Cautionary Statement Regarding Forward-Looking Statements" beginning on page 22 of this prospectus and/or listed in this prospectus under the section entitled "Risk Factors" beginning on page 24, all of which are difficult to predict and many of which are beyond Leap's control. Leap and Macrocure disclaim responsibility for their accuracy and cannot provide any assurance that the assumptions underlying the Projections are or were reasonable. Many of the assumptions reflected in the Projections are subject to change and none of the Projections reflect revised prospects for Leap or Leap's business, changes in general business or economic conditions or any other transactions or event that has occurred or that may occur and that was not anticipated at the time such financial information was prepared. The Projections speak as of the date that they were utilized by Macrocure's financial advisor for purposes of its analysis. Leap and Macrocure assume no obligation, nor does either Leap or Macrocure intend, to update or otherwise revise the Projections. There can be no assurance that the results reflected in any of the Projections will be realized or that actual results will not materially vary from the Projections. Therefore, the inclusion of the Projections in this prospectus should not be relied on as predictive of actual future events nor construed as financial guidance.

        For the reasons described above, readers of this prospectus are cautioned not to rely on the Projections as predictive of actual future events. Neither Leap nor Macrocure has made, in the merger agreement or otherwise, any representation to the other, or to any other person concerning any of the Projections.

        The following table presents, subject to the foregoing, a summary of the Projections.


Projections
(in millions)
Fiscal Year Ended December 31,

 
  2017   2018   2019   2020   2021   2022   2023   2024   2025   2026   2027   2028   2029   2030   2031  

Total Net Revenue

                  $ 78   $ 122   $ 219   $ 355   $ 582   $ 967   $ 1,629   $ 2,791   $ 3,910   $ 3,910   $ 3,910  

Total Unlevered After-Tax Income (Loss)

  $ (30 ) $ (55 ) $ (75 ) $ (115 ) $ (52 ) $ (34 ) $ 58   $ 282   $ 303   $ 507   $ 872   $ 1,514   $ 2,131   $ 2,131   $ 2,131  

Total Unlevered After-Tax Income (Loss) (Risk Adjusted)

  $ (30 ) $ (55 ) $ (58 ) $ (82 ) $ (20 ) $ (13 ) $ 11   $ 65   $ 111   $ 130   $ 191   $ 325   $ 435   $ 435   $ 435  

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Approval of the New Leap Charter and Issuance of Leap Common Stock

        Concurrently with the execution of the merger agreement, Leap obtained all approvals and consents of its stockholders necessary to effect the merger and the other transactions contemplated by the merger agreement, including approval of the issuance of Leap common stock as merger consideration to the existing Macrocure shareholders and the amendment of the Leap charter to be in the form of the New Leap Charter. No further approvals by the holders of Leap common stock are required to consummate the merger or the other transactions contemplated by the merger agreement. However, if additional approvals should be required for any reason, the Leap shareholders, in their respective voting agreements, have agreed to take such action.

Ownership of Leap Following the Merger

        As of the date of the Registration Statement of which this prospectus forms a part, but after giving effect to the stock options to be granted to key executives of Leap in contemplation of the merger, entities affiliated with HealthCare Ventures owned shares of preferred stock and notes convertible into shares of Leap common stock equal to approximately 69.1% of the Leap common stock on a fully diluted basis and Eli Lilly owned shares of preferred stock convertible into shares of Leap common stock equal to approximately 10.4% of the Leap common stock on a fully diluted basis. The remaining 20.5% of the fully diluted Leap common stock was held by Leap employees in the form of Leap stock options.

        As a result of the equity investment, the Recap, the Pre-Closing Leap Share Conversion, and the consummation of the merger, but without giving effect to the adoption of Leap's 2016 Equity Incentive Plan, we expect that:

    on a fully diluted basis, approximately 68.2% of the outstanding Leap common stock will be held by persons who were equityholders of Leap immediately prior to the effectiveness of the merger (including the HealthCare Ventures funds) and approximately 31.8% of the outstanding Leap common stock will be held by persons who were Macrocure equityholders immediately prior to the effectiveness of the merger; and

    all outstanding shares of Leap preferred stock and all outstanding notes, including any dividends or interest accrued thereon, will convert into shares of Leap common stock.

        In addition, Leap may also raise additional equity financing above the aforementioned $10.0 million in a private financing that would close simultaneously with the consummation of the merger to further finance its operations. The dilution from any additional equity financing is not reflected in the percentage ownership calculations presented above.

Governance of Leap Following the Merger

    Name of Company; Headquarters

        Following the consummation of the merger, the parent company shall continue to be called Leap Therapeutics, Inc., and Macrocure Ltd. will become Leap's wholly owned subsidiary. M-CO Merger Sub Ltd. will cease to exist. Leap's headquarters will be at 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141.

    Board of Directors

        Leap and Macrocure have agreed that, upon the consummation of the merger, the board of directors of Leap will be composed of seven members. The members of the board are expected to be:

    Christopher Mirabelli, currently the President and CEO and a director of Leap

    Thomas Dietz, currently a director of Leap

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    John Littlechild, currently a director of Leap

    James Cavanaugh, currently a director of Leap

    Joseph Loscalzo, currently a director of Leap

    Nissim Mashiach, currently the CEO of Macrocure

    William Li, currently an advisor to Macrocure

        Christopher Mirabelli will serve as chairman of the board of directors of Leap after the merger.

        The board of directors of the combined company following the merger will have a standing audit committee, a compensation committee and a nominating and corporate governance committee. Thomas Dietz will serve as chair of the audit committee of the board of directors of Leap. John Littlechild will serve as chair of the compensation committee of the board of directors of Leap. James Cavanaugh will serve as chair of the nominating and corporate governance committee of the board of directors of Leap.

        For a discussion of the material interests of the directors of Macrocure in the merger that may be in addition to, or different from, their interests as equityholders, see the sections entitled "Financial Interests of Macrocure's Directors and Executive Officers in the Merger" beginning on Page 224 of this prospectus.

    Management

        Leap and Macrocure expect that following the merger Dr. Christopher Mirabelli will continue as President and Chief Executive Officer of Leap, Douglas E. Onsi will continue to serve as Chief Financial Officer of Leap and Augustine Lawlor will continue to serve as the Chief Operating Officer of Leap.

Dividend Policy Following the Merger

        Leap has never declared or paid any cash dividends on its capital stock. Leap currently intends to retain all available funds and any future earnings to support its operations and finance the growth and development of its business. Leap does not intend to pay cash dividends on its common stock for the foreseeable future. Any changes to Leap's dividend policy will be made at the discretion of the board of directors of Leap and will depend upon many factors, including the financial condition of Leap, earnings, legal requirements, including limitations imposed by Delaware law, and other factors the board of directors of Leap deems relevant.

Amendment and Restatement of Leap Charter and Bylaws

        Pursuant to the terms of the merger agreement, immediately prior to the effective time of the merger, Leap's charter and bylaws will be amended to be in substantially the forms attached as Annex C and Annex D, respectively, of this prospectus. The New Leap Charter will, among other things, authorize 100,000,000 shares of common stock, authorize 10,000,000 shares of preferred stock and effectuate the Pre-Closing Leap Share Conversion Recap whereby each share of Leap common stock outstanding immediately prior to the merger (after giving effect to the Recap), will be automatically reclassified and changed into a number of shares of Leap common stock at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock.

Closing and Effective Time of the Merger

        The closing of the merger will take place on a date to be specified by Leap and Macrocure, which shall be no later than the second business day following the satisfaction or (to the extent permitted by law) waiver by the party or parties entitled to the benefits thereof of the conditions to the closing of the merger (other than those conditions that by their nature are to be satisfied at the closing, but

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subject to the satisfaction or (to the extent permitted by law) waiver of those conditions), or at such other place, time and date as shall be agreed in writing between Leap and Macrocure. Subject to the satisfaction or waiver of the conditions to the closing of the merger described in the section entitled "The Merger Agreement—Conditions to Consummation of the Merger" beginning on Page 104 of this prospectus, including the approval of the merger proposal by Macrocure shareholders at the special meeting, it is anticipated that the merger will close near the end of 2016 or the beginning of 2017. It is possible that factors outside the control of both companies could result in the merger being consummated at a different time, or not at all.

        The effective time will occur on the closing date of the merger as the parties may agree and specify in the articles of merger.

Regulatory Approvals

        Under the Companies Law, Macrocure and Merger Sub may not complete the merger without first making the following filings and notifications:

    Merger Proposal.   Macrocure and Merger Sub are required to file with the Israeli Companies Registrar a "merger proposal" setting forth specified details with respect to the merger, on or before three days after the calling of the Macrocure Shareholder Meeting. Macrocure and Merger Sub filed the required merger proposal with the Israeli Companies Registrar on August 31, 2016. Under the Companies Law, a minimum of 50 days must elapse from the date of the filing of the merger proposal by both merging companies with the Israeli Companies Registrar before the merger can become effective, although the merger may not be effective until the expiration of 30 days from the date of the approval of the merger by Macrocure's shareholders.

    Notice to Creditors.   In addition, each of Macrocure and Merger Sub is required to notify its creditors of the proposed merger. Pursuant to the Companies Law, a copy of the merger proposal must be sent to the secured creditors of each company within three days after the merger proposal is filed with the Israeli Companies Registrar, and, within four business days of such filing, known substantial creditors must be informed individually by registered mail of such filing and where the merger proposal can be reviewed. Non-secured creditors must be informed of the merger proposal by publication in two daily Hebrew newspapers circulated in Israel on the day that the merger proposal is filed with the Israeli Companies Registrar and, where necessary, elsewhere, and by making the merger proposal available for review. Each of Macrocure and Merger Sub has notified its respective creditors of the merger in accordance with these requirements, to the extent applicable and, because Macrocure's ordinary shares are traded on the NASDAQ Global Market, it also published an announcement of the merger in the New York Daily News on September 3, 2016, within three business days following the day on which the merger proposal was submitted to the Israeli Companies Registrar. Each of Macrocure and Merger Sub has notified the Israeli Companies Registrar of the notices to its respective creditors.

        Neither Leap nor Macrocure is required to make any filings or to obtain approvals or clearances from any antitrust regulatory authorities in the United States, Israel or other countries to consummate the merger. In the United States, Leap must comply with applicable federal and state securities laws rules and regulations in connection with the issuance of shares of Leap's common stock in the merger, including the filing with the Commission of the Registration Statement of which this prospectus forms a part.

        Leap and Macrocure have agreed to take, or cause to be taken, all actions, and do, or cause to be done, and assist and cooperate with the other in doing, all things necessary to avoid or eliminate each and every legal impediment that may be asserted under Israeli corporate law so as to enable the parties to the merger agreement to consummate and make effective, as promptly as practicable, the merger

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and the other transactions contemplated by the merger agreement in accordance with its terms. However, Leap and Macrocure and their respective subsidiaries are not required under the merger agreement to agree to or otherwise be required to commit to, execute or consummate any sale, divestiture, disposition or arrangement if doing so would, individually or in the aggregate, reasonably be expected to have a material adverse effect on the business, assets, results of operations or financial condition of Leap, Macrocure and their respective subsidiaries, taken as a whole. Further, the parties are not required to agree to any such actions with respect to the business or operations of Leap or Macrocure and their respective subsidiaries unless their effectiveness is conditioned on the consummation of the merger.

Federal Securities Law Consequences

        Following the effectiveness of the Registration Statement of which this prospectus forms a part, shares of Leap common stock issued in the merger will not be subject to any restrictions on transfer arising under the Securities Act or the Exchange Act, except for shares of Leap common stock issued to any Macrocure shareholder who may be deemed an "affiliate" for the purposes of Rule 144 of the Securities Act of Leap after the completion of the merger. Persons who may be deemed "affiliates" of the combined company generally include individuals or entities that control, are controlled by or are under common control with, the combined company and may include the executive officers and directors of the combined company as well as its principal shareholders. See "Shares Eligible for Future Sale" beginning on Page 241 of this prospectus.

        This prospectus does not cover resales of Leap common stock received by any person upon the completion of the merger, and no person is authorized to make any use of this prospectus in connection with any resale of Leap common stock.

Accounting Treatment

        The merger is being accounted for as an in-substance recapitalization of Leap, as the transaction is, in essence, an exchange of Leap common shares for cash. Apart from cash, the other assets and liabilities being acquired are nominal, and all Macrocure employees are expected to be terminated as of the effective time of the merger. Macrocure's cash and nominal assets and liabilities will be measured and recognized at their fair values as of the date of the merger, and consolidated with the assets, liabilities and results of operations of Leap after the consummation of the merger. Leap prepares its financial statements in accordance with GAAP, while Macrocure prepares its financial statements in accordance with International Financial Reporting Standards ("IFRS"). The nominal assets and liabilities remaining on the balance sheet of Macrocure as of June 30, 2016, and the historical operating results of Macrocure for the year ended December 31, 2015 and the six months ended June 30, 2016 are not expected to differ materially from amounts that would have been derived under GAAP. Accordingly, there are no adjustments for the conversion from IFRS to GAAP reflected in the unaudited pro forma condensed combined financial statements included elsewhere in this prospectus.

NASDAQ Market Listing

        Leap common stock is currently not traded on a stock exchange. Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

Transfer Agent and Registrar

        The transfer agent and registrar for Leap common stock is Continental Stock Transfer & Trust Company. The transfer agent and registrar's address is 17 Battery Pl Fl 8, New York, NY 10004.

Delisting and Deregistration of Macrocure Ordinary Shares

        If the merger is consummated, Macrocure ordinary shares will be delisted from NASDAQ and deregistered under the Exchange Act, and Macrocure will no longer be required to file periodic reports with the Commission.

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THE MERGER AGREEMENT

Explanatory Note Regarding the Merger Agreement

        The following section summarizes material provisions of the merger agreement, which is included in this prospectus as Annex A and is incorporated herein by reference in its entirety. The rights and obligations of each of Leap, Merger Sub and Macrocure are governed by the express terms and conditions of the merger agreement and not by this summary or any other information contained in this prospectus. Macrocure shareholders are urged to read the merger agreement carefully and in its entirety as well as this prospectus before making any decisions regarding the merger, including the approval of the merger Proposal.

        The merger agreement is included in this prospectus to provide you with information regarding its terms and is not intended to provide any factual information about Leap, Merger Sub or Macrocure. The merger agreement contains representations and warranties by each of the parties to the merger agreement. These representations and warranties have been made solely for the benefit of the other parties to the merger agreement and:

    may not be intended as statements of fact, but rather as a way of allocating the risk between the parties in the event the statements therein prove to be inaccurate;

    have been qualified by certain disclosures that were made between the parties in the merger agreement, which disclosures are not reflected in the merger agreement itself; and

    may apply standards of materiality in a way that is different from what may be viewed as material by you or other investors.

        Accordingly, the representations and warranties and other provisions of the merger agreement should not be read alone, but instead should be read together with the information provided elsewhere in this prospectus and in the documents of Macrocure incorporated by reference into this prospectus. See the section entitled "Where You Can Find More Information" beginning on Page 260 of this prospectus.

        This summary is qualified in its entirety by reference to the merger agreement.

Terms of the Merger

        Subject to the terms and conditions of the merger agreement, and in accordance with the Companies Law, at the effective time of the merger, Merger Sub will be merged with and into Macrocure, with Macrocure surviving the merger as a direct wholly owned subsidiary of Leap.

Completion and Effectiveness of the Merger

        Pursuant to the terms of the merger agreement, immediately prior to the effective time of the merger, Leap's charter and bylaws will be amended and restated to be in substantially the forms attached as Annex C and Annex D, respectively, of the Registration Statement of which this prospectus forms a part. As a result of the amendment to the Leap charter, each share of Leap common stock issued and outstanding immediately prior to the effective time of the merger (including (a) shares of Leap common stock to be issued (i) upon the conversion of all issued and outstanding shares of Leap preferred stock and (ii) upon the conversion of all outstanding Leap notes and (b) shares of Leap common stock issued upon the exercise of all outstanding stock options (including those to be issued to key executives in contemplation of the merger)) will be reclassified and are expected to be exchanged for a number of Leap common stock at a ratio that brings Leap's fully diluted capitalization to approximately 6,500,000 shares of common stock. No fractional shares of Leap common stock will be issued in connection with this Pre-Closing Leap Share Conversion, and each holder of shares of Leap common stock converted pursuant to the Pre-Closing Leap Share Conversion who would otherwise

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have been entitled to receive a fraction of a share of Leap common stock will receive cash in lieu thereof in accordance with the New Leap Charter.

        The consummation of the merger will take place on a date to be specified by Leap and Macrocure, which shall be no later than the second business day following the satisfaction or (to the extent permitted by law) waiver by the party or parties entitled to the benefits thereof of the conditions to the closing of the merger (other than those conditions that by their nature are to be satisfied at the closing, but subject to the satisfaction or (to the extent permitted by law) waiver of those conditions), or at such other place, time and date as shall be agreed in writing between Leap and Macrocure. The parties will cause the merger to be consummated by filing with the Israeli Registrar of Companies articles of merger meeting the requirements of Section 323(5) of the Companies Law, along with all other filings required under the Companies Law in connection with the merger. The merger will become effective at such time on the closing date.

        Leap and Macrocure are working to complete the merger as quickly as practicable and currently expect that the merger could be consummated near the end of 2016 or the beginning of 2017. However, Leap and Macrocure cannot predict the exact timing of the completion of the merger because it is subject to various conditions. It is possible that factors outside the control of Leap and Macrocure could result in the merger being consummated at a later time or not at all.

Allocation of the Merger Consideration Among Macrocure Equityholders

        Pursuant to the terms of the merger agreement, holders of (i) Macrocure ordinary shares will receive shares of Leap common stock, (ii) Macrocure options will become exercisable for shares of Leap common stock and (iii) Macrocure warrants will become exercisable for shares of Leap common stock. The number of shares of Leap common stock to be issued to all holders of Macrocure securities (including in respect of outstanding Macrocure options and warrants) will be determined pursuant to an exchange ratio that is based upon the number of shares of Leap common stock outstanding at the effective time of the merger, the amount of Macrocure's net cash as of a certain determination date and the fully diluted capitalization of Macrocure (excluding the out-of-the-money options) immediately prior to the effective time of the merger.

        At the effective time of the merger, each issued and outstanding Macrocure ordinary share will be converted into the right to receive that number of shares of Leap common stock as determined pursuant to the exchange ratio described in the merger agreement. No fractional shares of Leap common stock will be issued in connection with the merger. Instead, each Macrocure shareholder who otherwise would be entitled to receive a fractional share of Leap common stock (after aggregating all fractional shares of Leap common stock issuable to such holder) will be entitled to receive an amount in cash (rounded to the nearest whole cent), without interest, determined by multiplying such fraction of a share of Leap common stock by the value of a share of Leap common stock as determined by the board of directors of Leap in good faith based on the value per share reflected by the merger and the other transactions contemplated by the merger agreement. For a more complete discussion of the consideration received by holders of capital stock of Macrocure, please refer to "The Merger—Merger Consideration."

        In connection with the merger, each Macrocure option outstanding and unexercised immediately prior to the closing, whether or not vested, automatically and without any action on the part of the holder, shall be converted into an option to purchase a number of shares of Leap common stock equal to the product of (a) the number of shares of Macrocure ordinary shares that were subject to such option and (b) the exchange ratio set forth in the merger agreement (with the resulting number rounded down to the nearest whole number of shares of Leap common stock) and the per-share exercise price will be equal to the quotient of (i) the per-share exercise price of the Macrocure option and (ii) the exchange ratio (with the resultant price rounded up to the nearest whole cent), and Leap

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will assume the Macrocure Share Incentive Plans, and the options granted thereunder in accordance with their terms. All options, in accordance with their terms as approved prior to the consummation of the merger, will vest at the effective time of the merger.

        In connection with the merger, each Macrocure warrant outstanding immediately prior to the closing shall be converted, automatically and without any action on the part of the holder, into a warrant to purchase a number of shares of Leap common stock equal to the product of (a) the number of Macrocure ordinary shares that were subject to such warrant and (b) the exchange ratio set forth in the merger agreement (with the resulting number rounded down to the nearest whole number of shares of Leap stock). The per share exercise price of each warrant will also be equitably adjusted. Leap will assume each Macrocure warrant in accordance with its terms.

Merger Consideration and Adjustment

        Following the consummation of the merger and the other transactions contemplated by the merger agreement (but prior to giving effect to (i) the $10.0 million equity investment into Leap committed by certain affiliates of Leap or their designees and (ii) the adoption of Leap's 2016 Equity Incentive Plan, but after giving effect to options to be issued to key executives of Leap in contemplation of the merger), the current equityholders of Macrocure and the current equityholders of Leap are expected to own approximately 35% and 65%, respectively, of the combined company, assuming that Macrocure has net cash balance as of the closing date of the merger equal to or greater than $22.0 million. If Macrocure's net cash at the determination date is less than $22.0 million, the exchange ratio in the merger agreement proportionately adjusts on a linear basis to reduce the ownership percentage of the current equityholders of Macrocure. Assuming Macrocure has zero net cash (and Leap elected to waive its closing condition and consummate the merger), the current equityholders of Macrocure would own approximately 13% of the combined company. Consequently, the current equityholders (shareholders, optionholders and warrantholders (other than the holders of the out-of-the-money options)) of Macrocure will hold between approximately 13% and 35% of the Leap common stock, assuming exercise of the outstanding stock options, after consummation of the merger (but prior to giving effect to (i) the equity investment into Leap committed by certain affiliates of Leap and (ii) Leap's 2016 Equity Incentive Plan) based on Macrocure's net cash, as discussed below.

        The aggregate number of shares of Leap common stock that Leap issues in connection with the merger (including in respect of outstanding Macrocure options and warrants) will be determined by multiplying the percentage of the combined company that the current equityholders of Macrocure will own (subject to adjustment based on Macrocure's net cash) by a fraction, the numerator of which is the number of adjusted outstanding shares of Leap common stock (as described below) and the denominator of which is the percentage of the combined company that the current stockholders of Leap will own. The number of adjusted outstanding shares of Leap common stock will be equal to the sum of the total number of shares of Leap common stock outstanding immediately prior to the merger, plus the total number of shares of Leap common stock that are issuable upon exercise of Leap stock options. The exchange ratio for each Macrocure ordinary share will be determined by dividing (i) the aggregate number of shares of Leap common stock issued in connection with the merger (including in respect of outstanding Macrocure options and warrants) by (ii) the aggregate number of Macrocure ordinary shares, including Macrocure ordinary shares issuable upon the exercise of Macrocure warrants, Macrocure stock options (but not including the out-of-the-money options outstanding immediately prior to the consummation of the merger) and any other awards under Macrocure's Share Incentive Plans, in each case, outstanding immediately prior to the consummation of the merger, and will be calculated to the nearest 1/10,000 of a share.

        For illustrative purposes only, assuming Macrocure's net cash was determined to be $22.0 million or more, the exchange ratio for the Macrocure ordinary shares would have been approximately 0.1819 shares of Leap common stock for each Macrocure ordinary share. Therefore, if the merger had been

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consummated based on such calculation and you owned 1,000 Macrocure ordinary shares as of the effective time of the merger, you would have had the right to receive 181 shares of Leap common stock in exchange for your Macrocure ordinary shares plus cash in lieu of fractional shares. This example assumes a June 30, 2016 closing date and also assumes the following:

    Macrocure's level of net cash as of the determination date is equal to or greater than $22.0 million;

    17,932,079 ordinary shares of Macrocure are actually outstanding;

    578,680 ordinary shares of Macrocure are subject to outstanding Macrocure "out-of-the-money" stock options;

    994,008 ordinary shares of Macrocure are subject to outstanding Macrocure "in-the-money" stock options;

    315,330 ordinary shares of Macrocure are subject to outstanding Macrocure warrants; and

    6,500,000 shares of Leap common stock are actually outstanding or are subject to outstanding stock options (after giving effect to the Pre-Closing Leap Share Conversion and Recap described elsewhere in this prospectus).

        The exchange ratio will be determined, as discussed above and as described in the merger agreement, based upon the amount of "net cash" of Macrocure, which, as defined in the merger agreement, generally consists of Macrocure's cash and cash equivalents less expenses and liabilities, determined as of the closing date of the merger. For a more complete discussion of the determination of Macrocure's net cash, see the section entitled "Merger Agreement—Determination of Macrocure's Net Cash." In addition, one of the conditions to Leap obligations to consummate the merger is Macrocure's net cash as of the closing date being no less than $20.0 million as calculated pursuant to the provisions of the merger agreement.

        The following table illustrates the percentage ownership of the combined company by Macrocure's and Leap's current equityholders assuming various amounts of net cash of Macrocure as of the effective time of the merger.

Macrocure's Net Cash as of Effective Time
Calculated Pursuant to Merger Agreement
  Macrocure Equityholder
Ownership of
Outstanding Shares
of Combined Company
  Leap Equityholder
Ownership of Outstanding
Shares of Combined
Company
 

$20.0 million

    33.0 %   67.0 %

$21.0 million

    34.0 %   66.0 %

³ $22.0 million

    35.0 %   65.0 %

        Macrocure's net cash balance at the effective time is subject to numerous factors, many of which are outside of Macrocure's control. Macrocure will issue a news release after the final determination of the exchange ratio announcing the final exchange ratio and Macrocure's net cash balance at the determination date. If Macrocure's net cash at the closing date is less than $20.0 million, based on the manner of calculating net cash pursuant to the merger agreement, Macrocure would be unable to satisfy a closing condition for the merger, and Leap could elect to terminate the merger agreement or waive the condition.

Determination of Macrocure's Net Cash

        Macrocure's net cash as of the effective time of the merger will be calculated as of the date that is approximately five business days prior to the consummation of the merger. The closing of the merger could be delayed if Macrocure and Leap are not able agree upon the amount of Macrocure's net cash prior to the effective time.

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        Under the merger agreement, Macrocure's "net cash" is defined as the amount of its cash and cash equivalents, short-term investments of Macrocure and its subsidiaries, minus the aggregate amount of certain liabilities, including:

    all accounts payable, as determined by IFRS or GAAP;

    all indebtedness of Macrocure and its subsidiaries (including all principal, accrued interest thereon (and if such indebtedness is not prepayable, all remaining interest to be paid or accrued through maturity thereof)), and any other amounts payable to the holders of such indebtedness as a result of or in connection with, the consummation of the merger and the other transactions contemplated by the merger agreement

    all out-of-pocket closing or transaction costs in connection with the merger agreement and the transactions contemplated thereby, including amounts payable to financial advisors (including investment banks), attorneys, accountants or proxy solicitors that are paid, incurred or expected to be incurred, payable or subject to reimbursement by Macrocure, excluding all fees and costs related to the Registration Statement and related documents (as classified in the merger agreement) and 50% of all costs and expenses incurred in connection with stockholder litigation relating to the merger agreement or the transactions contemplated thereby;

    accrued expenses resulting from incurred but unbilled professional fees or operational costs pertaining to goods or services previously provided to Macrocure or any of its subsidiaries, projected through and as of the effective time of the merger;

    all other long-term liabilities that would be reflected in a balance sheet;

    all payment obligations under certain contracts disclosed by Macrocure, whether or not required on a balance sheet;

    all payments to any employee, director and/or consultant of Macrocure or any Macrocure Subsidiary required to be made at or after the closing date pursuant to employment agreements or other arrangements;

    all amounts payable in connection with any third-party consents, waivers, amendments, and the like, required to consummate the merger;

    all lease and other payments under any leases of Macrocure or any of the Macrocure Subsidiaries, including, without limitation, any termination payments, balloon or similar payments;

    all costs and expenses relating to the 104H Tax Ruling; and

    all other liabilities and obligations, the amount of which is known and certain as of the effective time of the merger, and is unrelated to any action or omission of Leap.

Exchange of Shares in the Merger

        At the effective time of the merger, by virtue of the merger and without any action on the part of Leap, Merger Sub or Macrocure or the holders of any Macrocure ordinary shares, each issued and outstanding Macrocure ordinary share will be converted into the right to receive the number of fully paid and nonassessable shares of Leap common stock equal to the number of ordinary shares held by such holder multiplied by the exchange ratio.

        Promptly after the consummation of the merger, Continental Stock Transfer & Trust Company as the exchange agent for the merger, will establish an exchange fund to hold the merger consideration to be paid in connection with the merger to the holders of record of Macrocure ordinary shares (as of immediately prior to the consummation of the merger). The exchange fund will consist of shares of

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Leap common stock and cash to be paid in lieu of fractional shares of Leap common stock (if and as applicable).

        As promptly as practicable following the consummation of the merger, the exchange agent will mail to each holder of record of Macrocure ordinary shares a letter of transmittal and instructions for surrendering the record holder's stock certificates in exchange for the merger consideration. Upon proper surrender of a Macrocure share certificate, together with a properly completed and duly executed letter of transmittal in accordance with the exchange agent's instructions, such share certificate will be cancelled and the holder of such share certificate will be entitled to receive (i) the number of whole shares of Leap common stock issuable to such holder pursuant to the merger and (ii) cash in lieu of any fractional share of Leap common stock issuable to such holder (if and as applicable).

        Following the consummation of the merger, each certificate representing shares of Macrocure ordinary shares that has not been surrendered will represent only the right to receive (i) shares of Leap common stock issuable pursuant to the merger and (ii) cash in lieu of any fractional share of Leap common stock to which the holder of any such certificate is entitled (if and as applicable). No interest shall be paid or accrued on any cash in lieu of fractional shares or any such unpaid dividends and distributions payable to holders of Macrocure share certificates.

        Any holder of Macrocure ordinary shares may be subject to withholding under the Internal Revenue Code, or under another provision of state, local or foreign tax law. To the extent such amounts are withheld and paid to the appropriate governmental entity, they will be treated as having been paid to the holder to whom such amounts would otherwise have been paid pursuant to the merger agreement.

        HOLDERS OF MACROCURE ORDINARY SHARES SHOULD NOT SURRENDER THEIR MACROCURE SHARE CERTIFICATES UNTIL THEY RECEIVE A LETTER OF TRANSMITTAL FROM THE EXCHANGE AGENT WITH INSTRUCTIONS FOR THE SURRENDER OF MACROCURE SHARE CERTIFICATES.

Fractional Shares

        No fractional shares of Leap common stock will be issuable to holders of Macrocure ordinary shares pursuant to the merger. Instead, each holder of Macrocure ordinary shares who would otherwise be entitled to receive as merger consideration a fraction of a share of Leap common stock, after aggregating all fractional shares of Leap common stock issuable to such holder, will be entitled to receive a cash payment in lieu of such fractional share in an amount equal to the product of such fraction and the value of a share of Leap common stock at the consummation of the merger agreement, as determined in good faith by Leap's board of directors and upon surrender of such holder's certificates representing Macrocure ordinary shares (if certificates were issued).

Representations and Warranties

        The merger agreement contains generally reciprocal representations and warranties, except as otherwise indicated below. Each of Leap and Macrocure has made representations and warranties regarding, among other things:

    corporate organization, standing and corporate or other organizational power;

    ownership of subsidiaries;

    capital structure;

    authority with respect to the execution and delivery of the merger agreement and the due and valid execution and delivery of the merger agreement;

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    absence of conflicts with, or violations of, organizational documents, other contracts and applicable laws;

    required regulatory filings and consents and approvals of governmental entities;

    accuracy of Commission and other regulatory reports;

    fair presentation of financial statements;

    GAAP compliance with respect to financial statements (solely in the case of Leap);

    IFRS compliance with respect to financial statements (solely in the case of Macrocure);

    any advisors' fees payable in connection with the merger;

    absence of certain changes and events from January 1, 2016 to the date of the merger agreement;

    conduct of business in the ordinary course since the date of the most recent audited financial statements;

    absence of pending, or knowledge of pending, legal proceedings;

    tax matters;

    labor and benefits matters, including matters related to employee benefit plans, and compliance with ERISA and other employment laws;

    internal controls and disclosure controls and procedures;

    compliance with applicable laws and licenses;

    certain material contracts;

    environmental liabilities;

    inapplicability of state takeover statutes;

    accuracy of information supplied or to be supplied for use in this prospectus and any amendments or supplements hereto;

    absence of certain transactions, contracts or arrangements with affiliates;

    intellectual property;

    compliance with laws and regulatory compliance

    compliance with healthcare laws and requirements related to quality and safety of products;

    compliance with anti-corruption laws;

    insurance matters;

    accuracy of books and records;

    grants and subsidies matters; and

    receipt of an opinion from Raymond James as to the fairness, from a financial point of view, of the merger consideration to Macrocure holders of Ordinary Shares (solely in the case of Macrocure).

        The merger agreement also contains certain representations and warranties of Merger Sub, including, without limitation, those relating to corporate organization, lack of prior business activities,

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capitalization, absence of material assets or liabilities and authority with respect to the execution and delivery of the merger agreement.

        Many of the representations and warranties in the merger agreement are qualified by a "materiality" or "material adverse effect" standard (that is, they will not be deemed to be untrue or incorrect unless their failure to be true or correct would be material or, individually or in the aggregate (or with respect to certain specified representations, individually but not in the aggregate), would have a material adverse effect, as the case may be). For purposes of the merger agreement, a "material adverse effect" means, with respect to a person, any events or developments that, individually or in the aggregate, prevent or materially delay the ability of such person to consummate the merger and the other transactions contemplated by the merger agreement, or have a material adverse effect on the business, properties, assets (including intangible assets), capitalization, liabilities, financial condition or results of operations of such person and its subsidiaries, taken as a whole, except that the definition of "material adverse effect" excludes any effect that results from or arises in connection with:

    changes in general economic or political conditions or the securities market in general (whether as a result of acts of terrorism, war (whether or not declared), armed conflicts or otherwise) to the extent they do not disproportionately affect such Person and its Subsidiaries, taken as a whole;

    changes in or affecting the industries in which such Person operates to the extent they do not disproportionately affect such Person and its Subsidiaries, taken as a whole, in any material respect; and

    changes, effects or circumstances resulting from the announcement or pendency of this agreement or the consummation of the Transactions or compliance with the terms of this agreement.

Conduct of Business

        Each of Leap and Macrocure has agreed to certain covenants in the merger agreement governing the conduct of its respective business between the date of the merger agreement and the effective time of the merger. In general, each of Leap and Macrocure has agreed to (i) conduct its business, and cause its subsidiaries to conduct their business, in the ordinary course in all material respects and (ii) use commercially reasonable efforts to maintain and preserve intact its business organization and advantageous business relationships, except in each case, as required by law, as expressly contemplated or permitted by the merger agreement, as disclosed in writing to the other party prior to the signing of the merger agreement or as consented to in writing by the other party. Leap has also agreed to use commercially reasonable efforts to perform its development plan, except as required by law, as expressly contemplated or permitted by the merger agreement and as disclosed in writing to Macrocure prior to the signing of the merger agreement, or as otherwise consented to by Macrocure.

        In addition, each of Leap and Macrocure has agreed to specific restrictions relating to the conduct of its business and its subsidiaries' businesses, between the date of the merger agreement and the effective time of the merger except in each case, as required by law, as expressly contemplated or permitted by the merger agreement, as disclosed in writing to the other party prior to the signing of the merger agreement or as consented to in writing by the other party.

        Leap has agreed that it will not, and will not permit of any of its subsidiaries to:

    issue or grant any shares of its capital stock or other securities, except for shares of common stock, stock options, warrants or other securities that are either exercisable for its common stock or will convert into its common stock prior to the consummation of the merger;

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    adjust, split, combine or reclassify any of its capital stock, other than as will be effected prior to the consummation of the merger (including, without limitation, any such adjustment, split, combination or reclassification pursuant to the its pre-closing share exchange and conversion pursuant to the terms of the merger agreement);

    make, declare or pay any dividend, or make any other distribution (including interest) on, or directly or indirectly redeem, purchase or otherwise acquire, any outstanding security, except (i) dividends paid by any of its subsidiaries to Leap itself or to another subsidiary, (ii) conversions and exchanges of securities of Leap pursuant to merger agreement, (iii) any stock dividend declared and paid prior to the consummation of the merger, (iv) forfeitures and cashless settlements made in connection with its issued and outstanding options pursuant to the merger agreement, and (v) pursuant to, and in connection with, the royalty agreement and the right to receive royalties in accordance with the terms thereof;

    amend its charter or bylaws, except as contemplated by, or required for its compliance with, the merger agreement;

    enter into or amend any contract that would reasonably be expected to prevent or materially impede, interfere with, hinder or delay the consummation of the merger and the related transactions;

    implement or adopt any material change in its tax accounting or financial accounting policies, practices or methods, other than as may be required by applicable law, GAAP or regulatory guidelines;

    incur any indebtedness for borrowed money other than (i) under the convertible promissory note outstanding as of the execution of the merger agreement and (ii) debt to be paid off prior to the consummation of the merger;

    amend the license agreement by and between it and Eli Lilly and Leap, dated as of January 3, 2011;

    amend any of the related party agreements references in its disclosure letter to the merger agreement, or enter into any new agreements with a related party, except (i) as permitted or necessary under the merger agreement (ii) with respect to the compensation payable to any of its non-employee directors, (iii) to provide for indemnification of its officers and directors, (iv) as required by any third party investor participating in its outside financing and (v) as would not adversely affect its rights or obligations thereunder;

    enter into, amend, or terminate an agreement, obligation, or series of related transactions that would cause it to have an upward or downward deviation of more than twenty percent (20%) from the aggregate expense forecast for the period(s) presented in the development plan previously provided to Macrocure; or

    agree, commit, resolve or propose to take any of the actions prohibited above.

        Macrocure has agreed that it will not, and will not permit of any of its subsidiaries to:

    incur any indebtedness or make any loan or advance or enter into any swap or hedging transaction;

    adjust, split, combine or reclassify any of its capital stock or other issued and outstanding securities;

    make, declare or pay any dividend, or make any other distribution on, or directly or indirectly redeem, purchase or otherwise acquire, any outstanding security, except for forfeitures and cashless settlements in connection with its issued and outstanding warrants;

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    issue, deliver, sell, grant, pledge or otherwise encumber or subject to any lien (i) any of its outstanding securities or (ii) any rights that are linked in any way to the price of any share capital of its outstanding securities, except (A) pursuant to the exercise of options outstanding as of the date of the merger agreement, (B) for issuances between its wholly owned subsidiaries, (C) as set forth in its disclosure letter to the merger agreement;

    solicit, initiate or facilitate any inquiries, proposals or offers to purchase or otherwise acquire any of its outstanding securities or execute or enter into any letter of intent, memorandum of understanding, agreement in principle, acquisition agreement, option or other similar agreement in connection with the issuance, sale or grant thereof;

    except as set forth in its disclosure letter to the merger agreement, (i) increase the compensation or benefits of any of its directors, officers or employees, or enter into, establish, amend or terminate any of its employee benefit plans for or in respect of any shareholder, officer, director, other employee, agent, consultant or affiliate, other than as required under such plans as were in effect as of the date of the merger agreement , (ii) accelerate the time of payment or vesting of, or the lapsing of restrictions with respect to, or fund or otherwise secure the payment of, any compensation or benefits under any of its employee benefit plans or (iii) hire any new employees;

    sell, transfer, mortgage, encumber or otherwise dispose of any of its properties or assets, or release any material indebtedness, other than to a subsidiary or in the ordinary course of business consistent with past practice;

    enter into any material new line of business;

    settle any claim, action or proceeding if such settlement would require any payment by it or any subsidiary of an amount in excess of $200,000 individually or $400,000 in the aggregate, or would obligate it or any subsidiary to admit any wrongdoing, to grant any material rights (other than agreement to pay the cash settlement amount agreed upon), to take any material action or impose any material restrictions or material liabilities on its business, or would not provide it or its subsidiaries with a full release from any and all liability arising in connection with any such claim, action or proceeding;

    directly or indirectly make, or agree to directly or indirectly make, any acquisition or investment either by merger, consolidation, purchase of stock or securities, contributions to capital, property transfers, or by purchase of any property or assets of any third party, or make any capital expenditures;

    amend its charter or the similar organizational documents of any material subsidiary in any material respect;

    enter into or amend any contract or take any other action if such contract, amendment or action would reasonably be expected to (i) prevent or materially impede, interfere with, hinder or delay the consummation of the merger or any of the other transactions, other than in accordance with its non-solicitation obligations, or (ii) give rise to any obligation or liability that would survive the consummation of the merger;

    implement or adopt any material change in its tax accounting or financial accounting policies, practices or methods, other than as may be required by applicable law, IFRS or GAAP (as applicable) or regulatory guidelines;

    enter into or amend any contract to the extent the consummation of the merger or any related transactions, or its compliance with the provisions of the merger agreement, would reasonably be expected to violate, conflict with, result in a breach of any provision of or the loss of any material benefit under, constitute a default under, result in the termination or cancelation under,

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      accelerate the performance required by, or result in the creation of any lien upon its material properties or assets, any provision of such contract or amendment;

    apply for, negotiate or receive a tax ruling from the Israeli Tax Authority on its own behalf or on behalf of any of its shareholders or directors, officers or employees, other than those expressly contemplated by the provisions of the merger agreement;

    apply for or receive a grant; or

    agree, commit, resolve or propose to take any of the actions prohibited by the above.

No Solicitation of Takeover Proposals

        Pursuant to the non-solicitation provisions set forth in the merger agreement, Macrocure has agreed that it will not, nor will it cause its subsidiaries or affiliates to, directly or indirectly, (i) solicit, initiate or knowingly facilitate any inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, a takeover proposal (as discussed below), (ii) engage or otherwise participate in any discussions or negotiations regarding, or furnish to any person any non-public information in connection with, or for the purposes of facilitating, any inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, a takeover proposal or (iii) execute or enter into any acquisition agreement (as discussed below), and Macrocure will use reasonable best efforts to cause its representatives to do the same.

        An acquisition agreement means any letter of intent, memorandum of understanding, agreement in principle, acquisition agreement, merger agreement, option or other similar agreement regarding, or that is intended to result in, or would reasonably be expected to lead to, a takeover proposal. The merger agreement also requires Macrocure and its subsidiaries, affiliates and representatives to immediately (i) cease any solicitation, discussions or negotiations with any persons that may be ongoing with respect to a takeover proposal, or any inquiry, proposal or offer that would reasonably be expected to lead to a takeover proposal, (ii) request the prompt return or destruction of all confidential information previously furnished to any person in connection with a takeover proposal and (iii) terminate all physical and electronic dataroom access previously granted to any such person, its subsidiaries and/or its representatives.

        A takeover proposal means any proposal or offer with respect to any (i) direct or indirect acquisition of 20% or more of the consolidated assets of Macrocure or Leap (as the case may be) and its subsidiaries (based on the fair market value thereof), (ii) direct or indirect acquisition of 20% or more of the outstanding or newly issued Macrocure ordinary shares or Leap common stock, or the outstanding voting power of Macrocure or Leap (or options, rights or warrants to purchase, or securities convertible into or exchangeable for, such Macrocure ordinary shares or Leap common stock or other securities representing such voting power), (iii) tender offer or exchange offer that if consummated would result directly or indirectly in any person or group (or the shareholders of any person or group) beneficially owning 20% or more of the outstanding Macrocure ordinary shares or Leap common stock or the outstanding voting power of Macrocure or Leap or (iv) merger, consolidation, share exchange, business combination, recapitalization, liquidation, dissolution or other similar transaction involving Macrocure or Leap or any of its subsidiaries.

        The merger agreement requires that Macrocure promptly (and in any event within 48 hours) notify Leap in writing of its receipt of any takeover proposal and provide to Leap an unredacted copy of the takeover proposal, if made in writing, and unredacted copies of all written materials constituting or containing terms or conditions with respect to such takeover proposal exchanged between Macrocure and any third party in connection with a takeover proposal, and a written summary of all material terms and conditions of any such takeover proposal, to the extent these are not made in writing. In addition, the merger agreement requires Macrocure to inform Leap on a prompt basis, from and after

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such notice, of material developments with respect to any such takeover proposal or any material substantive discussions or negotiations relating to any such takeover proposal.

        Notwithstanding the non-solicitation provisions described above, if at any time prior to obtaining Macrocure's shareholder approval of the merger, Macrocure receives a bona fide written takeover proposal not resulting in any material respect from a breach of the non-solicitation provisions of the merger agreement, Macrocure or any of its subsidiaries or transaction representatives is permitted to enter into an acceptable confidentiality agreement and furnish information with respect to Macrocure and enter into discussions with the person or group making such bona fide written takeover proposal and engage in or otherwise participate in discussions or negotiations with the person or group making such takeover proposal if the Macrocure board determines in good faith (after consultation with its outside counsel and financial advisors) that such takeover proposal constitutes, or is reasonably likely to lead to, a superior proposal (as discussed below) and the failure to take such actions would be reasonably likely to be inconsistent with its fiduciary duties of an Israeli company under Israeli law. In any such event, Macrocure must promptly (but in any event within 48 hours) provide to Leap any information that is provided to any person or group given such access which was not previously provided to Leap.

        A superior proposal means any bona fide takeover proposal by a third party, the receipt of which by Macrocure did not result in any material respect from its breach of the non-solicitation provisions of the merger agreement and which, if consummated, would result in such third party (or in the case of a direct merger between such third party or an affiliate of such third party and Macrocure, the shareholders of such third party) acquiring, directly or indirectly, more than 50% of the voting power of the Macrocure ordinary shares or more than 50% of the consolidated assets of Macrocure and its subsidiaries (based on the fair market value thereof) for consideration consisting of cash and/or securities that the Macrocure board determines in good faith (after consultation with its outside counsel and financial advisors) is more favorable to Macrocure's shareholders from a financial point of view than the merger agreement, taking into account all legal, regulatory, financial and other aspects of such proposal and of the merger agreement deemed relevant by the Macrocure board or any such committee, as well as any changes to the terms of the merger and the related transactions irrevocably proposed by Leap in response to such offer.

        Leap's board of directors will not, nor will any committee thereof, (i) recommend or approve the approval of, or publicly propose to recommend or approve the approval of, any takeover proposal of Leap, (ii) refrain from recommending against any takeover proposal of Leap that is a tender offer or exchange offer within 10 business days after the commencement thereof or (iv) enter into or propose publicly to execute or enter into (or cause or permit Leap or any of its subsidiaries to execute or enter into or propose publicly to execute or enter into) an acquisition agreement (other than any confidentiality agreement containing terms comparable to Leap's confidentiality agreement with Macrocure).

Efforts to Complete the Merger

        Leap and Macrocure have each agreed to:

    take, or cause to be taken, all actions, and do, or cause to be done, and assist and cooperate with the other parties in doing, all things necessary to consummate and make effective, as promptly as practicable, the merger and the other transactions contemplated by the merger agreement;

    take all action necessary to ensure that no state takeover statute or similar statute or regulation is or becomes applicable to the merger agreement or any transaction contemplated by the merger agreement and, if any takeover statute or similar statute or regulation becomes applicable to the merger agreement or any transaction contemplated by the merger agreement,

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      take all action necessary to ensure that the merger and the other transactions contemplated by the merger agreement may be consummated as promptly as practicable;

    provide all necessary notices, reports, registrations, submissions of information, applications and other filings to, and obtain as promptly as practicable all consents, licenses, permits, waivers, approvals, clearances, and authorizations, orders or nonactions from, any governmental entity or other person that are required to be obtained by Leap, Merger Sub or Macrocure, or any of their respective subsidiaries, in connection with the consummation of the merger and the other transactions contemplated by the merger agreement;

    prosecute all such filings and consents with all appropriate diligence;

    furnish all information required to be furnished in connection with the consents of or filings with any governmental entity, and promptly cooperate with and furnish information in connection with any such requirements imposed upon either of them or any of their respective subsidiaries in connection with the merger agreement and the transactions contemplated by the merger agreement;

    execute and deliver any additional instruments necessary to consummate the merger and the other transactions contemplated by the merger agreement and to fully carry out the purposes of the merger agreement;

    facilitate obtaining any final order, writ, judgment or decree approving the transactions contemplated by the merger agreement;

    defend any lawsuits or other legal proceedings, whether judicial or administrative, challenging the merger agreement or the consummation of the transactions contemplated by the merger agreement, including seeking to have any stay or temporary restraining order entered by any court or other governmental entity vacated or reversed;

    take, or cause to be taken, all actions, and do, or cause to be done, and assist and cooperate with the other in doing, all things necessary to avoid or eliminate each and every impediment that may be asserted by any governmental entity in order to enable the parties to consummate, as promptly as practicable, the merger and the other transactions contemplated by the merger agreement, including proposing, negotiating, committing to and effecting any terms, conditions, obligations, commitments or liabilities or the entry into any other arrangements, as are necessary or reasonably advisable in order to obtain the consents, avoid the entry of, and the commencement of litigation seeking the entry of, or to effect the dissolution of, any injunction that would otherwise have the effect of materially delaying or preventing the consummation of the merger and the other transactions contemplated by the merger agreement (subject to certain exceptions described below); and

    make all filings and deliver all notices required under all applicable antitrust laws and take all necessary actions to cause the expiration or termination of the applicable waiting periods under any applicable antitrust laws or to obtain any consents required under any antitrust laws.

Disclosure Documents

        Each of Leap and Macrocure shall cooperate and use their reasonable best efforts to prepare, and Macrocure agreed to cause to be furnished to the Commission, a proxy statement as an exhibit to a Report of Foreign Private Issuer on Form 6-K, and each of Leap and Macrocure agreed to cooperate and use their reasonable best efforts to prepare, and work together to cause to be filed with the Commission this Registration Statement in connection with the registration under the Securities Act, as amended, of the shares of Leap common stock to be issued by virtue of the merger. Leap and Macrocure agreed to use their reasonable best efforts to complete the foregoing as promptly as

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practicable, no later than 30 days after signing of the merger agreement. Each of Leap and Macrocure agreed to use their reasonable best efforts to cause the Registration Statement to become effective as promptly as practicable, after such filing. Each of Leap and Macrocure agreed to furnish all information concerning itself and their subsidiaries, as applicable, to the other parties as the other parties may reasonably request in connection with such actions and the preparation of the Registration Statement and proxy statement.

Merger Proposal

        Pursuant to the merger agreement, Macrocure and Merger Sub were required, as promptly as practicable after the execution and delivery thereof, to cause the merger proposals (in the Hebrew language) to be executed in accordance with Section 316 of the Israeli Companies Law. In addition, Macrocure and Merger Sub were required, as promptly as practicable after the execution and delivery of the merger agreement, to call a general meeting of its shareholders and Merger Sub shall call a general meeting of its shareholders, and each of Macrocure and Merger Sub shall deliver the merger proposals to the Israeli Registrar of Companies within three days from the calling of such shareholder meetings in accordance with Section 317(a) of the Israeli Companies Law.

        Macrocure and Merger Sub were also each required to cause a copy of their respective merger proposal to be delivered to each of their respective secured creditors, if any, no later than three days after the date on which the merger proposals are delivered to the Israeli Registrar of Companies, and each of their respective material creditors, if any, no later than three days after the date on which the merger proposals were delivered to the Israeli Registrar of Companies, and to promptly inform their respective non-secured creditors of their respective merger proposal and its contents in accordance with Section 318 of the Israeli Companies Law. No more than three business days following the date on which such notice is sent to the creditors, Macrocure and Merger Sub shall inform the Israeli Registrar of Companies, in accordance with Section 317(b) of the Israeli Companies Law, that notice was given to their respective creditors under Section 318 of the Israeli Companies Law.

        In addition to the foregoing, Macrocure and, if applicable, Merger Sub, shall:

    publish a notice to its creditors, stating that a merger proposal was submitted to the Israeli Registrar of Companies and that the creditors may review the merger proposal at the office of the Israeli Registrar of Companies, Macrocure's registered offices or Merger Sub's registered offices, as applicable, and at such other locations as Macrocure or Merger Sub, as applicable, may determine, in (i) two daily Hebrew newspapers, on the day that the merger proposals are submitted to the Israeli Registrar of Companies, (ii) a popular newspaper in the United States, no later than three business days following the day on which the merger proposals were submitted to the Israeli Registrar of Companies, and (iii) if required, in such other manner as may be required by any applicable law and regulations; and

    within four business days from the date of submitting the merger proposals to the Israeli Registrar of Companies, send a notice by registered mail to all of the "material creditors" (as such term is defined in the Israeli Companies Law) that Macrocure or Merger Sub, as applicable, is aware of, in which it shall state that a merger proposal was submitted to the Israeli Registrar of Companies and that the creditors may review the merger proposal at such additional locations, if such locations were determined in the notice referred to above.

Meeting of Macrocure's and Merger Sub's Shareholders

        Macrocure is obligated under the merger agreement to call, give notice of and hold a meeting of its shareholders for the purposes of voting on the merger agreement and the transactions contemplated thereby to be held (on a date selected by Macrocure and consented to by Leap) as promptly as practicable after the date of the merger agreement, but no earlier than 35 days from the filing of the merger proposals. Macrocure has agreed to use its best efforts to solicit from its shareholders proxies for voting on the matters to be voted on at its shareholder meeting. No later than three days after the approval of the merger by Macrocure's shareholders at such meeting, Macrocure shall inform the Israeli Registrar of Companies that such approval has been obtained.

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        No later than three days after the approval of the merger agreement, the merger and other transactions contemplated by the merger agreement by Merger Sub's sole shareholder, Merger Sub shall inform the Israeli Registrar of Companies of such decision of Merger Sub's sole shareholders with respect to the merger.

Regulatory Approvals

        Neither Leap nor Macrocure is required to make any filings or to obtain approvals or clearances from any antitrust regulatory authorities in the United States, Israel or other countries to consummate the merger. In the United States, Leap must comply with applicable federal and state securities laws and NASDAQ rules and regulations in connection with the issuance of shares of Leap common stock in the merger, including the filing with the Commission of the Registration Statement of which this prospectus forms a part.

Macrocure Share Incentive Plans, Stock Options and Warrants

        Upon consummation of the merger, Leap shall assume Macrocure's 2008 and 2013 Share Incentive Plans and all obligations of Macrocure thereunder. As soon as practicable after the consummation of the merger, Leap shall deliver appropriate notices to the holders of Macrocure options setting forth such holders' rights under the merger agreement, and the option award agreements held by such holders shall continue in effect on the same terms and conditions, subject to the following adjustments.

        Each outstanding option and warrant, whether or not vested, to purchase Macrocure ordinary shares unexercised prior to the consummation of the merger shall be converted into an option or warrant, as applicable, to purchase Leap common stock. All rights with respect to each Macrocure option or warrant shall be assumed by Leap in accordance with its terms. Accordingly, from and after the consummation of the merger each option or warrant assumed by Leap may be exercised solely for shares of Leap common stock.

        The number of shares of Leap common stock subject to each outstanding Macrocure option or warrant assumed by Leap shall be determined by multiplying the number of Macrocure ordinary shares that were subject to such option or warrant, as applicable, by the exchange ratio and rounding the resulting number down to the nearest whole number of shares of Leap common stock. The per share exercise price for the Leap common stock issuable upon exercise of each Macrocure option or warrant assumed by Leap shall be determined by dividing the per share exercise price of the Macrocure ordinary shares subject to such option or warrant, as applicable, by the exchange ratio and rounding the resulting exercise price up to the nearest whole cent. Any restriction on the exercise of any option assumed by Leap shall continue in full force and effect and the term, exercisability, vesting schedule and other provisions of such option shall, subject to certain exceptions set forth in the merger agreement, otherwise remain unchanged. Likewise, any restriction on any warrant assumed by Leap shall continue in full force and effect and the term and other provisions of such warrant shall otherwise remain unchanged.

Leap Stock Options

        Each outstanding option, whether or not vested, to purchase Leap common stock unexercised prior to the Pre-Closing Leap Share Conversion shall be converted into an option to purchase a number of shares of Leap common stock determined by multiplying the number of shares of Leap common stock that were subject to such option, by the conversion ratio and rounding the resulting number down to the nearest whole number of shares of Leap common stock. The per share exercise price for the Leap common stock issuable upon exercise of each Leap option shall be determined by dividing the per share exercise price of the shares of Leap common stock subject to such option by the conversion ratio and rounding the resulting exercise price up to the nearest whole cent.

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Israeli Tax Rulings

        Macrocure instructed its Israeli counsel to prepare and file with the Israeli Tax Authority (the "ITA") an application for a ruling confirming, among other things, that the conversion of Macrocure Section 102 Options shall not be regarded as a violation of the provisions of Section 102 and the "requisite holding period" (as such term is defined in Section 102) so long as that such options will be deposited with the Section 102 Trustee until (at least) the end of the respective holding period (which ruling may be subject to customary conditions regularly associated with such a ruling) (the "Options Tax Ruling"). If the Options Tax Ruling is not granted prior to the consummation of the merger, Macrocure shall seek to obtain prior to the consummation an interim tax ruling confirming, among other things, that Leap and any person acting on its behalf shall be exempt from Israeli withholding tax in relation to the conversion of Macrocure Section 102 Options pursuant to the merger agreement (the "Interim Options Tax Ruling"). To the extent that prior to the consummation of the merger an Interim Options Tax Ruling shall have been obtained, then all references herein to the Options Tax Ruling shall be deemed to refer to such Interim Options Tax Ruling, until such time that a final definitive Options Tax Ruling is obtained.

        In addition, Macrocure instructed its Israeli counsel to prepare and file with the ITA an application for a ruling confirming, among others, that with respect to holders of Macrocure Ordinary Shares that are non-Israeli residents (as defined in the Israeli Tax Ordinance or as will be determined by the ITA), (A) exempting Leap, the Exchange Agent and their respective agents from any obligation to withhold Israeli Tax from any consideration payable or otherwise deliverable pursuant to the merger agreement, including the merger consideration, or clarifying that no such obligation exists, or (B) clearly instructing Leap, the Exchange Agent and their respective agents on how such withholding is to be executed, and in particular, with respect to the classes or categories of holders of the Macrocure ordinary shares from which tax is to be withheld (if any), the rate or rates of withholding to be applied and how to identify any such non-Israeli residents (we refer to this ruling as the Withholding Tax Ruling).

        Each of Leap and Macrocure has agreed to cause its Israeli counsel, advisors and accountants to coordinate all activities, and to cooperate with each other, with respect to the preparation of any written or oral submissions or applications that may be necessary, proper or advisable to obtain the Options Tax Ruling (including the Interim Options Tax Ruling) and the Withholding Tax Ruling. The final text of the Interim Options Tax Ruling, the Options Tax Ruling and the Withholding Tax Ruling will be subject to the prior written confirmation of Leap or its counsel, which consent shall not be unreasonably withheld, conditioned or delayed. Neither Macrocure nor its representatives shall make any application to, or conduct any negotiation with, the ITA with respect to matters relating to the Options Tax Ruling, the Options Tax Ruling and the Withholding Tax Ruling without prior review and consent of Leap's representatives. To the extent that Leap's representatives elect not to participate in any such meeting or discussion, Macrocure's representatives will provide Leap's representatives a full and accurate report of the discussions and/or meetings held with the ITA. Should the written consent of Leap to the final version of the Options Tax Ruling, the Interim Options Tax Ruling or the Withholding Tax Ruling be required, such consent shall not be unreasonably withheld, conditioned or delayed.

NASDAQ Listing

        Macrocure's ordinary shares are currently listed on The NASDAQ Global Market under the symbol "MCUR." Following the merger, Macrocure ordinary shares will be delisted from The NASDAQ Global Market.

        Pursuant to the merger agreement, Leap agreed to use its commercially reasonable efforts to cause the shares of Leap common stock being issued in the merger to be approved for listing on the

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NASDAQ stock market at or prior to the consummation of the merger. Leap plans to list the Leap common stock to be issued in the merger on the NASDAQ stock market under the symbol "LPTX". Leap expects to submit an application for such listing shortly.

Directors

        The merger agreement provides that Leap will take all necessary action to cause, upon consummation of the merger, the Leap board to be composed of seven (7) directors (staggered in three classes). The directors shall initially be Christopher Mirabelli (who will serve as Chairman of the board), James Cavanaugh, John Littlechild, Thomas Dietz and Joseph Loscalzo, Nissim Mashiach and William Li. If either Nissim Mashiach or William Li for any reason shall be unable to serve on the board upon the consummation of the merger, Macrocure may designate a substitute designee who is reasonably acceptable to Leap. Any such designee shall be initially assigned to the classes of directors having a three-year term and two-year term, and, as set forth in the New Leap Bylaws, for a period of two years after the consummation of the merger, at least one such designee shall serve on any pricing committee for future financings (which committee charter shall require approval of disinterested directors with respect to any financing involving an affiliate of Leap that is entered into during the two year period immediately following the consummation of the merger).

Other Covenants and Agreements

        The merger agreement contains certain other covenants and agreements, including covenants relating to:

    cooperation between Leap and Macrocure in the preparation of this prospectus;

    confidentiality and access by each party to certain information about the other party during the period prior to the consummation of the merger;

    Macrocure will consult with Leap and use commercially reasonable efforts to keep Leap apprised of material developments regarding the defense or settlement of any shareholder litigation against Macrocure or its directors relating to the merger;

    causing any dispositions of Macrocure ordinary shares and any acquisitions of Leap common stock, in each case resulting from the merger and the other transactions contemplated by the merger agreement by each individual who will or may become subject to reporting requirements under the securities laws to be exempt under Rule 16b-3 promulgated under the Exchange Act;

    delivery of quarterly financials, together with applicable notes and a copy of the relevant management discussion and analysis, in compliance with GAAP or IFRS, to the other party within 45 days of the end of each calendar quarter; and

    cooperation between Leap and Macrocure in connection with public announcements.

        Leap has also agreed to have made, as of the consummation of the merger agreement, an equity investment of at least $10.0 million from funds affiliated with HealthCare Ventures for shares of Leap common stock, having no preferential or contractual rights senior to the rights of shares of its common stock issued as merger consideration to the holders of Macrocure ordinary shares. At or prior to the consummation of the merger, Leap will grant to key members of management under its 2012 Equity Incentive Plan options to purchase Leap common stock representing in the aggregate approximately 9% of the share capital of Leap anticipated to be outstanding immediately following the consummation of the merger, calculated on a fully diluted basis (but without taking into account or treating as issued any of the shares issuable upon exercise of the assumed out-of-the money options as of the consummation of the merger).

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        Leap has also agreed that it will assume all rights to indemnification, advancement of expenses and exculpation from liabilities for acts or omissions occurring at or prior to the consummation of the merger now existing in favor of the current or former directors or officers of Macrocure, acting in such capacities.

        Prior to the consummation of the merger, Macrocure will purchase a directors' and officers' liability insurance policy covering the seven (7) year period following the consummation of the merger. Such insurance shall cover the acts or omissions of the former directors and officers of Macrocure who were covered under its liability insurance policy immediately prior to the consummation of the merger, on terms with respect to coverage and amount no less favorable than those of such policy in effect immediately prior to the consummation of the merger.

Conditions to Consummation of the Merger

        The obligations of Leap, Merger Sub and Macrocure to consummate the merger are subject to the satisfaction or waiver by each of the parties to the merger agreement of various conditions that include, in addition to other customary closing conditions, the following:

    the certificate of merger shall have been received from the Israeli Registrar of Companies;

    approval of the merger by the affirmative vote of holders of a majority of the outstanding Macrocure ordinary shares present and entitled to vote at the Macrocure Shareholder Meeting;

    authorization for the listing on the NASDAQ of the shares of Leap common stock to be issued to Macrocure shareholders in the merger, subject to official notice of issuance;

    the expiration of the thirty (30) day waiting period set forth in Section 323 of the Israeli Companies Law;

    effectiveness of the Registration Statement of which this prospectus forms a part and no stop order suspending the effectiveness of the Registration Statement having been issued or proceedings for that purpose having been initiated or threatened by the SEC;

    no material order, injunction or decree issued by any court or agency of competent jurisdiction or other legal restraint or prohibition preventing the consummation of the merger or any of the other transactions contemplated by the merger agreement being in effect;

    Macrocure and Leap having agreed in writing the calculations of Macrocure's net cash and Leap's accounts payable as of the closing, or an independent accountant having delivered its report with respect to either calculation pursuant to the merger agreement;

    the representations and warranties of the other party set forth in the merger agreement must be true and correct without reference to any qualification as to materiality, except where, with respect to certain representations of Leap and Macrocure, a failure to be true and correct would not have a material adverse effect on the party making the representations and warranties; and

    the other party must have performed in all material respects all of its agreements and covenants required by the merger agreement and provided a certificate to such effect.

        In addition, Leap's obligation to consummate the merger is subject to the satisfaction or waiver of the following conditions at or prior to the effective time:

    there must not have occurred, since the date of the merger agreement, any material adverse effect on Macrocure and its subsidiaries that is continuing; and

    the minimum net cash of Macrocure is not less than $20.0 million, calculated pursuant to the terms of the merger agreement.

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        In addition, Macrocure's obligation to effect the merger is subject to the satisfaction or waiver of the following conditions at or prior to the effective time:

    there must not have occurred, since the date of the merger agreement, any material adverse effect on Leap and its subsidiaries that is continuing;

    Leap shall have consummated the equity investment of at least $10.0 million from funds associated with HealthCare Ventures;

    all outstanding Leap notes have been converted and, after giving effect to the conversion of the Leap notes into shares of Leap common stock, Leap does not have any indebtedness for borrowed money as of the consummation of the merger;

    Leap shall have completed the Pre-Closing Leap Share Conversion and Recap;

    Leap shall have adopted its 2016 Equity Incentive Plan;

    the net accounts payable of Leap as of immediately prior to consummation of the merger, calculated pursuant to the terms of the merger agreement, shall not be greater than $1.0 million;

    the receipt by Macrocure of the Section 104H Tax Ruling from the Israeli Tax Authority, on terms that are reasonably satisfactory to Macrocure;

    the employment agreements entered into by certain members of Leap's management team upon the signing of the merger agreement remain in full force and effect;

    each of William Li and Nissim Mashiach (or an alternate, determined pursuant to the terms of the merger agreement) will be appointed to Leap's board of directors; and

    each of Leap's shareholders shall have delivered to Leap a properly completed and signed Internal Revenue Service Form W-9 (or an applicable successor form).

Termination of the Merger Agreement

        The merger agreement may be terminated at any time prior to the consummation of the merger, whether before or after the receipt of the approval of the Macrocure shareholders of the merger proposal, by action taken or authorized by the board of directors of the terminating party or parties under the following circumstances:

    by mutual written consent of Leap and Macrocure;

    by either Leap or Macrocure:

    if any governmental entity issues a final and nonappealable order permanently enjoining or otherwise prohibiting the consummation of the merger or the other transactions contemplated by the merger agreement, except that no party may terminate the merger agreement if such party's breach of its obligations proximately contributed to the issuance of such order;

    if the holders of Macrocure ordinary shares fail to approve the merger proposal at Macrocure's Shareholder Meeting or any adjournment or postponement thereof at which the vote was taken; provided that Macrocure cannot terminate the merger agreement, unless Macrocure has paid, when known, the expense fee of up to $750,000, or (i) if a breach of its obligations under the merger agreement was the principal factor contributing to not obtaining its shareholders' approval, (ii) during the thirty (30) day period after the Macrocure shareholder approval is not obtained if Leap commences litigation against the Macrocure shareholders that are parties to the voting agreements alleging breach of such stockholders obligations under the voting agreements and during the ninety (90) days from

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      the date such litigation is commenced, and (iii) if Macrocure failed to give effect to a proxy delivered by Leap pursuant to the rights granted to Leap under any voting agreement unless the failure is mandated pursuant to a court order; or

      if the merger is not consummated by January 31, 2017, as such date may be extended for up to an additional ninety (90) days in the aggregate, provided that (i) no party may terminate the merger agreement if such party's breach of its obligations was the principal cause to the failure to close by such date, (ii) Macrocure may not terminate the merger agreement under this provision after the Macrocure Shareholder Meeting if its shareholders' approval is not obtained and (iii) Macrocure may not terminate the agreement under this provision if Macrocure has not received the requisite tax ruling, subject to certain exceptions. The date after which the parties may terminate the merger agreement under this provision is referred to as the end date.

    by Leap or Macrocure if there shall have been a breach of any of the covenants or agreements or any inaccuracy of any of the representations or warranties of Macrocure or Leap (as the case may be), such that the conditions to the consummation of the merger relating to such covenants or representations or warranties would not then be satisfied and such breach or inaccuracy is incapable of being cured, or is not cured, by the end date or, if capable of being cured by the end date such breaching party has not commenced good faith efforts to cure the breach or inaccuracy within ten (10) days following receipt of written notice from the other party and thereafter is not continuing such good faith efforts;

    by Leap if, prior to obtaining the approval of the Macrocure shareholders of the merger proposal, Macrocure's board adversely changes its recommendation that Macrocure's shareholders approve the merger and related transactions;

    by Macrocure at any time prior to obtaining the approval of the Macrocure shareholders in connection with entering into an acquisition agreement with a third party in accordance with the non-solicitation provisions of the merger agreement, provided that Macrocure pays Leap the termination and expense fees discussed below; or

    by Leap or Macrocure, on or at any time after the end date, if Macrocure has not received the Section 104H tax ruling from the Israeli Tax Authorities, on terms which are reasonably satisfactory to Macrocure; provided that Macrocure pays Leap the fees described below; and provided further that Macrocure may not terminate the merger agreement if Macrocure's breach of obligations under the merger agreement was a principal contributing factor to the failure to receive the tax ruling and that Leap may not terminate the merger agreement if certain of the closing conditions are not satisfied by the time that Leap is seeking its right to exercise the agreement or if Leap is unable to confirm in writing that certain conditions will be satisfied.

        If the merger agreement is validly terminated, the merger agreement will become void and have no effect, without any liability or obligation on the part of any party, except as expressly set forth therein (including any obligation of Macrocure to pay the termination fee or the expense fee, as described below), unless a party is in willful and material breach of any representation, warranty, covenant or agreement set forth in the merger agreement.

Fees and Expenses

        The merger agreement provides all fees and expenses incurred in connection with the merger agreement and the transactions contemplated thereby shall be paid by the party incurring such expenses, except that the fees and expenses, other than attorneys' and accountants' fees and expenses, associated with the printing and filing of this Registration Statement, the printing, furnishing and

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distribution of Macrocure's proxy statement as an exhibit to a Report of Foreign Private Issuer on Form 6-K shall be shared equally by Leap and Macrocure.

        In the event that the merger agreement:

    is terminated by either Leap or Macrocure as a result of Macrocure's failure to obtain the requisite approval of its shareholders and Macrocure enters into a definitive agreement with respect to a takeover proposal or otherwise engages or agrees to engage in any transaction that constitutes a takeover within 12 months of the date the merger agreement is terminated;

    is terminated by Macrocure in connection with its entering into a definitive agreement with respect to a superior competing proposal prior to receipt of the requisite approval of its shareholders; or

    is terminated by Leap in the event that Macrocure's board adversely changes its recommendation that Macrocure's shareholders approve the merger and related transactions, other than when the change in such recommendation was made as a result of a material adverse effect on Leap,

Macrocure will pay Leap a termination fee equal to $1.2 million, plus, if not previously paid pursuant to the merger agreement, an expense fee equal to the lesser of (i) $750,000 and (ii) the aggregate of all reasonable and documented out-of-pocket fees and expenses (including all fees and expenses of counsel, accountants, financial advisors and investment bankers to Leap), incurred by Leap and Merger Sub in connection with or related to the authorization, preparation, negotiation, execution and performance of the merger agreement, any filings or submissions under applicable laws in connection with the transactions contemplated in the merger agreement or any other matters related thereto. The expense fee is also payable upon a termination by Leap of the merger agreement following a failed Macrocure shareholder vote, absent an adverse change in the recommendation of the Macrocure board as a result of a Leap material adverse effect.

        In the event that Leap terminates the merger agreement on or after January 31, 2017 due to Macrocure's failure to receive the Section 104H tax Ruling from the Israeli Tax Authority, Macrocure will pay to Leap $1.6 million within two business days after such termination.

Amendments, Extensions and Waivers

        The merger agreement may be amended by the parties, by action taken or authorized by their respective boards of directors, at any time, provided that, after receiving the approval of Macrocure's shareholders to the merger, any amendment of the merger agreement that requires further approval of the Macrocure shareholders pursuant to applicable law will be effective only with the approval of such shareholders.

        At any time prior to the consummation of the merger, Leap (on behalf of itself and Merger Sub) and Macrocure may, to the extent legally allowed, (i) extend the time for performance of any obligations or other acts of such parties, (ii) waive any inaccuracies in the representations and warranties of such parties contained in the merger agreement and (iii) waive compliance by such parties with any of the agreements or conditions contained in the merger agreement.

No Third Party Beneficiaries

        The merger agreement is not intended to, and does not, confer upon any person other than Leap, Macrocure, and Merger Sub any rights or remedies, except as specifically provided by the merger agreement.

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Specific Enforcement

        Leap and Macrocure acknowledged and agreed in the merger agreement that irreparable damage would occur in the event that any of the provisions of the merger agreement were not performed in accordance with their specific terms or were otherwise breached, and that monetary damages, even if available, would not be an adequate remedy. Therefore, the parties fully intend for specific performance to be an available remedy for breaches of the merger agreement. In addition, the parties agreed that, prior to termination of the merger agreement, they will be entitled to seek an injunction or injunctions to prevent breaches of the merger agreement and to enforce specifically the performance of terms and provisions of the merger agreement without proof of actual damages in addition to any other remedy to which they are entitled at law or in equity. The parties further agreed not to assert that a remedy of specific performance is unenforceable, invalid, contrary to law or inequitable for any reason, nor to object to a remedy of specific performance on the basis that a remedy of monetary damages would provide an adequate remedy for any such breach. Each party further acknowledged and agreed that such agreements relating to specific performance are an integral part of the merger and the transactions contemplated by the merger agreement and that, without these agreements, the other party (in the case of Macrocure) or other parties (in the case of Leap and Merger Sub) would not have entered into the merger agreement. Each party further agreed that no other party or any other person will be required to obtain, furnish or post any bond or similar instrument in connection with or as a condition to obtaining any remedy relating to specific performance, and each party irrevocably waived any right it may have to require the obtaining, furnishing or posting of any such bond or similar instrument.

Compliance with Deadlines

        The parties agreed that failure to comply with certain deadlines after using reasonable best efforts to comply will not be deemed a breach of the merger agreement so long as the party continues to use reasonable best efforts to cure such failure as promptly as possible.

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SELECTED HISTORICAL FINANCIAL DATA OF LEAP

        The following table sets forth selected historical financial information of Leap for each of the periods presented (in thousands, except share and per share data). We have derived the statement of operations data for the years ended December 31, 2014 and 2015 and the balance sheet and other data as of December 31, 2014 and 2015 from our audited consolidated financial statements appearing elsewhere in this prospectus. The statement of operations data for the six months ended June 30, 2015 and 2016 and the balance sheet and other data as of June 30, 2016 have been derived from our unaudited consolidated financial statements appearing elsewhere in this prospectus and have been prepared on the same basis as the audited consolidated financial statements. In the opinion of management, the unaudited data reflects all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the financial information in those statements. Our consolidated financial statements have been prepared in accordance with GAAP. Our historical results are not necessarily indicative of results that should be expected in the future, and the results for the six months ended June 30, 2016 are not necessarily indicative of the results to be expected for the full year ending December 31, 2016.

        The following table should be read together with "Management's Discussion and Analysis of Financial Condition and Results of Operations—Leap" beginning on page 156 of this prospectus and Leap's audited consolidated financial statements for the years ended December 31, 2014 and 2015,

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unaudited consolidated financial statements as of June 30, 2016 and for the six months ended June 30, 2016 and 2015 and related notes beginning on page F-2 of this prospectus.

 
  Year Ended
December 31,
  Six Months Ended
June 30,
 
 
  2014   2015   2015   2016  
 
  (in thousands)
 

Statement of Operations Data:

                         

Operating expenses

                         

Research and development

  $ 6,714   $ 10,411   $ 5,380   $ 10,211  

General and administrative (including related party expenses of $134, $98, $97 and $127, respectively)

    918     1,511     393     2,075  

Total operating expenses

    7,632     11,922     5,773     12,286  

Loss from operations

    (7,632 )   (11,922 )   (5,773 )   (12,286 )

Interest income

        1         4  

Interest expense—related party

    (73 )   (129 )   (88 )   (342 )

Net loss

  $ (7,705 ) $ (12,050 ) $ (5,861 ) $ (12,624 )

Net loss per share attributable to common stockholders, basic and diluted(1)

  $   $   $   $  

Shares used to compute basic and diluted net loss per share attributable to common stockholders(1)

                 

(1)
There were no common shares of Leap outstanding during the years ended December 31, 2014 and 2015

 
  December 31,    
 
 
  June 30,
2016
 
 
  2014   2015  
 
  (in thousands)
 

Balance Sheet and other Data:

                   

Cash

  $ 238   $ 405   $ 2,496  

Working capital (deficit)(2)

    (4,359 )   (5,174 )   (18,010 )

Total assets

    1,138     1,260     3,633  

Notes payable and accrued interest—related party

    3,144     3,141     16,383  

Total liabilities

    4,668     5,668     20,651  

Redeemable convertible preferred stock

    33,060     65,881     68,178  

Total stockholders' deficiency

    (36,590 )   (70,289 )   (85,196 )

(2)
We define working capital (deficit) as current assets less current liabilities.

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SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF MACROCURE

        The following tables set forth Macrocure's selected consolidated financial data. Macrocure derived the selected consolidated statements of loss and other comprehensive loss data for the years ended December 31, 2015, 2014 and 2013 and its selected consolidated statement of financial position data as of December 31, 2015 and 2014 from its audited consolidated financial statements and the related notes thereto included elsewhere in this prospectus. Macrocure's selected consolidated statements of loss and other comprehensive loss data for the year ended December 31, 2012 and selected consolidated statement of financial position data as of December 31, 2013 and 2012 has been derived from Macrocure's audited consolidated financial statements not included in this prospectus. Macrocure derived the selected consolidated statements of loss and other comprehensive loss data for the six months ended June 30, 2016 and 2015, and the summary consolidated statement of financial position data as of June 30, 2016, from Macrocure's unaudited condensed interim consolidated financial statements included elsewhere in this prospectus. The unaudited condensed interim consolidated financial statements include, in the opinion of Macrocure's management, all adjustments that management considers necessary for the fair presentation of the financial information set forth in those statements. Macrocure has prepared its financial statements in accordance with International Financial Reporting Standards, or IFRS, as issued by the International Accounting Standards Board, or IASB.

        Macrocure's selected consolidated statements of loss and other comprehensive loss data for the year ended December 31, 2011 and its selected consolidated statement of financial position data as of December 31, 2011 has been omitted from this prospectus because of Macrocure's status as an emerging growth company under the JOBS Act, and as per related guidance provided by the Commission.

        The information presented below is qualified by the more detailed historical consolidated financial statements of Macrocure set forth in this prospectus, and should be read in conjunction with those consolidated financial statements, the notes thereto and the discussion under "Information About Macrocure—Operating and Financial Review and Prospects" included elsewhere in this prospectus.

 
  Year Ended December 31,   Six Months Ended
June 30,
 
 
  2015   2014   2013   2012   2016   2015  
 
  (in thousands except share and per share data)
 

Consolidated Statements of Loss and Other Comprehensive Loss Data:

                                     

Operating expenses(1):

                                     

Research and development expenses, net

  $ 15,369   $ 15,542   $ 9,303   $ 7,168   $   $ 10,071  

General and administrative expenses

    5,720     5,374     4,567     1,631     2,152     3,544  

Operating loss

    (21,089 )   (20,916 )   (13,870 )   (8,799 )   (2,152 )   (13,615 )

Financing income (expenses), net

    138     (4,504 )   (4,305 )   1,043     34     125  

Loss before income tax

    (20,951 )   (25,420 )   (18,175 )   (7,756 )   (2,118 )   (13,490 )

Taxes on income

    (152 )   (31 )   (149 )       (7 )   (87 )

Loss for the period

  $ (21,103 ) $ (25,451 ) $ (18,324 ) $ (7,756 ) $ (2,125 ) $ (13,577 )

Other comprehensive income (loss)

  $ 26   $ (26 ) $   $         15  

Total comprehensive loss

  $ (21,077 ) $ (25,477 ) $ (18,324 ) $ (7,756 ) $ (2,125 ) $ (13,562 )

Net loss per share (basic and diluted)

  $ (1.16 ) $ (2.15 ) $ (2.46 ) $ (1.05 ) $ (0.12 ) $ (0.74 )

Weighted average number of ordinary shares used in computing loss per share, basic and diluted

    18,248,340     11,863,372     7,444,042     7,421,088     18,249,159     18,247,641  

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  As of December 31,   As of
June 30,
 
 
  2015   2014   2013   2012   2016  
 
  (in thousands)
 

Consolidated Statements of Financial Position Data:

                               

Cash and cash equivalents

  $ 20,966   $ 10,868   $ 18,995   $ 15,322   $ 25,463  

Working capital(2)

    26,638     44,229     17,593     14,510     25,044  

Total assets

    28,149     48,699     20,738     17,709     25,624  

Total current liabilities

    1,279     2,488     1,971     1,499     577  

Total non-current liabilities

                3,114      

Total shareholders' equity

    26,870     46,211     18,767     13,096     25,047  

(1)
Includes share-based compensation expense as follows:

 
  Year Ended December 31,   Six Months
Ended June 30,
 
 
  2015   2014   2013   2012   2016   2015  
 
  (in thousands)
   
   
 

Research and development expenses, net

  $ 386   $ 452   $ 0   $ 210   $ 0   $ 386  

General and administrative expenses

    1,334     1,211     2,648     31     302     875  

Total share-based compensation expenses

    1,720     1,663     2,648     241     302     1,261  
(2)
Macrocure defines working capital as total current assets minus total current liabilities.

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SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA

        The following selected unaudited pro forma condensed combined financial data for the year ended December 31, 2015, and as of and for the six months ended June 30, 2016 give effect to the proposed merger of Merger Sub with and into Macrocure, which will be accounted for as a recapitalization of Leap. The selected unaudited pro forma condensed combined financial data presented below is based on, and should be read in conjunction with, the historical financial statements of Leap that appear elsewhere in this prospectus, the unaudited pro forma condensed combined financial statements that appear elsewhere in this prospectus, including the footnotes thereto, and the historical financial statements of Macrocure that appear elsewhere in this prospectus. See the sections entitled, "Where You Can Find More Information" and "Unaudited Pro Forma Condensed Combined Financial Statements," for additional information.

        The following selected unaudited pro forma condensed combined balance sheet data as of June 30, 2016 combines the historical condensed balance sheets of Leap and Macrocure as of June 30, 2016, giving pro forma effect to the merger, including the equity investment of $10.0 million, as if the merger had been completed on June 30, 2016. The following selected unaudited pro forma condensed combined statements of operations data for the year ended December 31, 2015 and the six months ended June 30, 2016 combine the historical condensed statements of operations data of Leap and Macrocure for the same periods, giving pro forma effect to the merger, including the equity investment of $10.0 million, as if it had been completed on January 1, 2015.

        The selected unaudited pro forma condensed combined financial data is presented for illustrative purposes only and is not necessarily indicative of the actual or future financial position or results of operations that would have been realized if the proposed merger had been completed as of the dates indicated in the unaudited pro forma condensed combined financial statements or that will be realized upon the consummation of the proposed merger.

 
  Year Ended
December 31, 2015
  Six Months Ended
June 30, 2016
 
 
  (in thousands)
 

Statements of Operations Data

             

Loss from operations

  $ (33,011 ) $ (14,438 )

Net loss

  $ (33,024 ) $ (14,407 )

Net loss attributable to common stockholders

  $ (33,024 ) $ (14,407 )

Net loss per share attributable to common stockholders, basic and diluted(1)

  $ (3.81 ) $ (1.44 )

 

 
  As of
June 30, 2016
 
 
  (in thousands)
 

Balance Sheet Data

       

Cash and cash equivalents(1)

  $ 37,959  

Working capital(1)(2)

  $ 32,167  

Total assets(1)

  $ 39,257  

Total liabilities

  $ 6,095  

Accumulated deficit

  $ (87,072 )

Total stockholders' equity(1)

  $ 33,162  

(1)
Includes the impact of proceeds received from, and shares of Leap common stock issued in connection with, the equity investment of $10.0 million.

(2)
We define working capital as current assets less current liabilities.

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COMPARATIVE HISTORICAL AND UNAUDITED PRO FORMA PER SHARE DATA

        The following tables set forth certain historical, pro forma and pro forma equivalent per share financial information of Leap common shares and Macrocure ordinary shares. The unaudited pro forma and pro forma equivalent per share financial information gives effect to the merger and related transactions as if they had occurred on June 30, 2016 for book value per share data and as of January 1, 2015 for net loss per share data. The information in the table is based on, and should be read together with, the historical financial statements of Leap that appear elsewhere in this prospectus, the unaudited pro forma condensed combined financial statements that appear elsewhere in this prospectus, including the notes thereto, and the historical financial statements of Macrocure that appear elsewhere in this prospectus. See the sections entitled, "Where You Can Find More Information" and "Unaudited Pro Forma Condensed Combined Financial Statements."

        The following unaudited pro forma net loss per share data for the year ended December 31, 2015 and the six months ended June 30, 2016 was calculated using the historical condensed combined statements of operations data of Leap and Macrocure for the same periods, giving pro forma effect to the merger, including the equity investment of $10.0 million, as if it had been completed on January 1, 2015. The following unaudited pro forma book value per share data as of June 30, 2016 was calculated using the historical condensed combined balance sheets of Leap and Macrocure as of June 30, 2016, giving pro forma effect to the merger, including the equity investment of $10.0 million, as if it had been completed on June 30, 2016.

        The unaudited pro forma data is presented for illustrative purposes only and is not necessarily indicative of actual or future financial position or results of operations that would have been realized if the proposed merger had been completed as of the dates indicated or will be realized upon the completion of the proposed merger. Leap and Macrocure have not declared or paid any dividends during the periods presented.

 
  As of and for
the year ended
December 31, 2015
  As of and for
the six
months ended
June 30, 2016
 

Leap(1)

             

Book value per share—historical(2)

  $   $  

Basic and diluted net loss per share—historical

         

Macrocure

   
 
   
 
 

Book value per share—historical(2)

  $ 1.58   $ 1.40  

Basic and diluted net loss per share—historical

  $ (1.16 ) $ (0.12 )

Combined

   
 
   
 
 

Book value per share—pro forma(3)

        $ 3.11  

Basic and diluted net loss per share—pro forma

  $ (3.81 ) $ (1.44 )

Macrocure Unaudited Pro Forma Equivalent Data per Share(4)

   
 
   
 
 

Book value per share—historical

  $   $ 0.57  

Basic and diluted net loss per share—historical

  $ (0.69 ) $ (0.26 )

(1)
There were no shares of Leap common stock outstanding during the year ended December 31, 2015 or the six months ended June 30, 2016.

(2)
Historical book value per share is calculated by taking total shareholders' equity divided by total outstanding shares of common stock.

(3)
Combined pro forma book value per share is calculated by taking pro forma combined total shareholder' equity divided by pro forma combined total outstanding shares of common stock.

(4)
Macrocure Unaudited Pro Forma Equivalent Data per share is calculated by applying the assumed share exchange ratio of 0.1819 to the Combined unaudited pro forma data per share

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UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

        On August 29, 2016, Leap entered into a definitive merger agreement with Macrocure, a publicly held, clinical-stage biotechnology company based in Petach Tikva, Israel, and M-Co Merger Sub Ltd. ("Merger Sub"), a wholly owned subsidiary of Leap that was established for the sole purpose of effecting the merger of Macrocure with Merger Sub, with Macrocure continuing after the merger as a wholly owned subsidiary of Leap.

        The unaudited pro forma condensed combined balance sheet as of June 30, 2016 and the unaudited pro forma condensed combined statements of operations for the six months ended June 30, 2016 and for the year ended December 31, 2015, which give effect to the proposed merger of Merger Sub with and into Macrocure are presented herein. The proposed merger is being accounted for as an in-substance recapitalization of Leap, as the transaction is, in essence, an exchange of shares of Leap common stock (and options and warrants exercisable therefor) for cash. Apart from cash, the other assets and liabilities being acquired are nominal, and all Macrocure employees are expected to be terminated as of the effective time of the merger. Macrocure's cash and nominal assets and liabilities will be measured and recognized at their fair values as of the date of the merger, and combined with the assets, liabilities and results of operations of Leap after the consummation of the merger. The nominal assets and liabilities remaining on the balance sheet of Macrocure as of June 30, 2016, and the historical operating results of Macrocure for the year ended December 31, 2015 and the six months ended June 30, 2016 are not expected to differ materially from amounts that would have been derived under GAAP. Accordingly, while the Macrocure historical audited and unaudited financial statements were prepared in accordance with IFRS, as issued by the IASB, there are no adjustments for the conversion from IFRS to GAAP reflected in the unaudited pro forma condensed combined financial statements included in this prospectus. See Note 1, "Description of the Transaction and Basis of Pro Forma Presentation", and Note 4, "Accounting Policies and Merger Pro Forma Adjustments" in the accompanying notes to unaudited pro forma condensed combined financial statements for additional information.

        The unaudited pro forma condensed combined balance sheet combines the unaudited condensed balance sheets of Leap and Macrocure as of June 30, 2016 and gives effect to the merger as if it had been completed on June 30, 2016. The unaudited pro forma condensed combined statements of operations for the year ended December 31, 2015 and the six months ended June 30, 2016 combine the historical condensed statements of operations of Leap and Macrocure, giving pro forma effect to the merger as if it had been completed on January 1, 2015. The historical financial information has been adjusted in the unaudited pro forma condensed combined financial statements to give effect to pro forma events that are (1) directly attributable to the merger, (2) factually supportable, and (3) with respect to the statements of operations, expected to have a continuing impact on the combined company.

        The unaudited pro forma condensed combined financial statements presented are based on the assumptions and adjustments described in the accompanying notes. The unaudited pro forma condensed combined financial statements are presented for illustrative purposes and do not purport to represent what the financial position or results of operations would actually have been if the merger occurred as of the dates indicated or what such financial position or results would be for any future periods for the combined company. The unaudited pro forma condensed combined financial statements are based upon the respective historical consolidated financial statements of Leap and Macrocure, and should be read in conjunction with the:

    accompanying notes to the unaudited pro forma condensed combined financial statements;

    separate historical audited consolidated financial statements of Leap as of and for the years ended December 31, 2014 and 2015 included in this prospectus;

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    separate historical unaudited consolidated financial statements of Leap as of June 30, 2016 and for the six months ended June 30, 2015 and 2016 included in this prospectus;

    separate historical audited consolidated financial statements of Macrocure as of December 31, 2014 and 2015 and for the years ended December 31, 2013, 2014 and 2015 included in this prospectus;

    separate historical consolidated unaudited financial statements of Macrocure as of June 30, 2016 and for the six months ended June 30, 2015 and 2016 included in this prospectus; and

    management's discussion and analysis of financial condition and results of operations for both Leap and Macrocure and "Risk Factors" included in this prospectus.

        The unaudited pro forma condensed combined financial statements and adjustments have been prepared based upon currently available information and certain assumptions, which are described in the accompanying notes. Given that the accounting treatment for the merger as an in-substance recapitalization of Leap, and related transactions, including the Royalty Agreement, are dependent upon certain valuations and analyses that have yet to be completed or have not progressed to a stage where there is sufficient information for a definitive measurement, the assumptions, estimates and adjustments reflected in the unaudited pro forma condensed combined financial statements are preliminary and subject to further revision as additional information becomes available and additional valuations and analyses are performed. Upon consummation of the merger, final analyses will be performed. The determination of the final merger accounting and actual results may differ materially from the assumptions, estimates and adjustments reflected in the unaudited pro forma condensed combined financial statements. Furthermore, the accompanying pro forma condensed combined statements of operations do not reflect the financial impact of any expected costs savings, synergies, integration costs or non-recurring activities and one-time transaction costs that may be realized or incurred in subsequent reporting periods. In addition, the unaudited pro forma condensed combined financial statements do not reflect certain transactions that occurred subsequent to June 30, 2016. See Note 3, "Subsequent Transactions," in the accompanying notes to these unaudited pro forma condensed combined financial statements for additional information.

        The unaudited pro forma condensed combined statements of operations do not reflect certain amounts resulting from the merger that were determined to be of a non-recurring nature. In accordance with the terms of the merger agreement, immediately prior to the effective time of the merger, Leap will effect (i) the Recap, such that (a) all preferred stock of Leap then outstanding and (b) all of Leap's convertible promissory notes then outstanding, including accrued and unpaid interest, will convert into shares of Leap common stock, and (ii) the Pre-Closing Leap Share Conversion, such that each share of common stock issued and outstanding immediately prior to the closing, including shares subject to outstanding stock options, shall be converted into a fraction of a share of Leap common stock. Accordingly, all Leap share and per share amounts for all periods presented in these unaudited pro forma condensed combined financial statements and related notes have been adjusted retroactively, where applicable, to reflect the 1-for-10.4298 pre-closing Leap share conversion, which would have been the reverse stock split calculation if the merger were to have closed on June 30, 2016. The final reverse stock split will not be determined until the actual closing date. In addition, the pro forma condensed combined financial statements assume that Leap does not elect to exercise its right to adjust the exchange ratios presently contemplated by the merger agreement. The pro forma condensed combined financial statements, however, do give effect to the $10.0 million equity investment that is required as a condition to the consummation of the merger.

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UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET
As of June 30, 2016
(in thousands, except share and per share amounts)

 
  Historical    
   
   
 
 
  Pro Forma
Adjustments
   
  Pro Forma
Combined
 
 
  Leap   Macrocure   Note 4  

Assets

                             

Current assets:

                             

Cash and cash equivalents

  $ 2,496   $ 25,463   $ 10,000   (c)   $ 37,959  

Other receivable

        158               158  

Prepaid expenses and other current assets

    145                 145  

Total current assets

    2,641     25,621     10,000         38,262  

Property and equipment, net

    129     3             132  

Other assets

    863                 863  

Total assets

  $ 3,633   $ 25,624   $ 10,000       $ 39,257  

Liabilities and stockholders' equity

                             

Current liabilities:

                             

Trade and accounts payable

  $ 3,259   $ 577   $       $ 3,836  

Accrued expenses

    1,009         1,250   (e)     2,259  

Notes payable and accrued interest—related party

    16,383         (16,383 ) (a)      

Total current liabilities

    20,651     577     (15,133 )       6,095  

Convertible preferred stock, 42,500,000 shares authorized as of June 30, 2016

   
 
   
 
   
 
 

 

   
 
 

Series A redeemable convertible preferred stock, $0.001 par value; 9,000,000 shares designated; 9,000,000 shares issued and outstanding; liquidation preference of $11,438

    11,438         (11,438 ) (a)      

Sereis B convertible preferred stock, $0.001 par value; 21,500,000 shares designated; 21,500,000 shares issued and outstanding; liquidation preference of $27,331           

    27,331         (27,331 ) (a)      

Sereis C convertible preferred stock, $0.001 par value; 12.000,000 shares designated; 11,781,984 shares issued and outstanding; liquidation preference of $29,409           

    29,409         (29,409 ) (a)      

Stockholders' equity (deficiency)

   
 
   
 
   
 
 

 

   
 
 

Common stock—Leap ($0.001 par value)

            67   (a)     11  

                (60 ) (b)