Exhibit 10.1

Subscription Agreement Number:             

Issued to:             

in connection with the Offering by Mateon Therapeutics, Inc.

of

A Minimum of 20 and a Maximum of 80 Units at

$50,000 per Unit

With each Unit consisting of 250,000

Shares of Common Stock and

Warrants to Purchase 250,000 Shares of Common Stock

Placement Agent

DIVINE CAPITAL MARKETS LLC

39 BROADWAY

36TH FLOOR

NEW YORK, NEW YORK 10006

CONFIDENTIAL USE ONLY - MAY NOT BE REPRODUCED

NOTICES

NONE OF THE UNITS, THE COMMON STOCK OR WARRANTS INCLUDED IN THE UNITS OR THE SECURITIES UNDERLYING THE WARRANTS (COLLECTIVELY, THE “ SECURITIES ”) HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS. THESE SECURITIES ARE BEING OFFERED AND SOLD IN RELIANCE ON EXEMPTIONS FROM THE REGISTRATION REQUIREMENTS OF THESE LAWS. THE UNITS HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND EXCHANGE COMMISSION (THE “ COMMISSION ”) OR ANY STATE SECURITIES REGULATORY AUTHORITY NOR HAS THE COMMISSION OR ANY SUCH AUTHORITY PASSED UPON OR ENDORSED THE MERITS OF THE OFFERING OR THE ACCURACY OR ADEQUACY OF THIS SUBSCRIPTION AGREEMENT AND INVESTMENT LETTER AND/OR ANY OTHER INFORMATION DOCUMENTS PROVIDED BY THE COMPANY IN CONNECTION THEREWITH (COLLECTIVELY, THE “ INFORMATION DOCUMENTS ”). ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

IN MAKING AN INVESTMENT DECISION, INVESTORS MUST RELY ON THEIR OWN EXAMINATION OF THE PERSON OR ENTITY CREATING THE SECURITIES AND THE TERMS OF THE OFFERING, INCLUDING THE MERITS AND RISKS INVOLVED.

THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE SECURITIES ACT, AND THE APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. INVESTORS SHOULD BE AWARE THAT THEY WILL BE REQUIRED TO BEAR THE FINANCIAL RISKS OF INVESTMENT FOR AN INDEFINITE PERIOD OF TIME. CONSEQUENTLY, THE UNITS SHOULD BE CONSIDERED FOR PURCHASE ONLY AS A LONG-TERM INVESTMENT.

THE PURCHASERS SHOULD NOT CONSTRUE THE INFORMATION DOCUMENTS OR ANY COMMUNICATIONS IN CONNECTION THEREWITH AS LEGAL, TAX OR FINANCIAL ADVICE AND, ACCORDINGLY, MUST CONSULT THEIR OWN LEGAL, ACCOUNTING AND/OR FINANCIAL ADVISERS WITH RESPECT TO LEGAL, TAX AND RELATED MATTERS CONCERNING THIS INVESTMENT.

ANY INVESTOR SEEKING TAX ADVANTAGES SHOULD NOT PURCHASE UNITS. THIS INVESTMENT IS NOT A TAX SHELTER SINCE IT DOES NOT PROVIDE DEDUCTIONS WHICH WOULD BE AVAILABLE TO REDUCE INCOME FROM OTHER SOURCES. ACCORDINGLY, A DECISION TO PURCHASE THE UNITS SHOULD BE BASED SOLELY ON HER/HIS EVALUATION OF THE ECONOMIC CONSIDERATIONS OF THE TRANSACTION.

THE INFORMATION DOCUMENTS ARE FOR THE SOLE USE OF, AND CONSTITUTE AN OFFER ONLY TO, THE OFFEREE WHOSE NAME APPEARS ABOVE. ANY DISTRIBUTION OF THE INFORMATION DOCUMENTS, WHETHER IN WHOLE OR IN PART, TO ANY PERSON OTHER THAN SUCH OFFEREE AND HER/HIS AUTHORIZED AGENTS, AND ANY REPRODUCTION OF THE INFORMATION DOCUMENTS OR THE

DIVULGENCE OF ANY OF THEIR CONTENTS, IS STRICTLY PROHIBITED. THE OFFEREE NAMED ABOVE, BY ACCEPTING DELIVERY OF THE INFORMATION DOCUMENTS, AGREES TO RETURN THE INFORMATION DOCUMENTS, TO THE COMPANY, IF SUCH OFFEREE DOES NOT UNDERTAKE TO PURCHASE THE SECURITIES OFFERED HEREBY.

NO PERSON HAS BEEN AUTHORIZED TO MAKE ANY REPRESENTATION OR TO GIVE ANY INFORMATION WITH RESPECT TO THE COMPANY OR THE SECURITIES OFFERED HEREBY, EXCEPT THE INFORMATION CONTAINED HEREIN (AS AMENDED OR SUPPLEMENTED FROM TIME TO TIME) OR IN THE EXHIBITS HERETO AND, IF MADE OR GIVEN, SUCH REPRESENTATION OR INFORMATION MUST NOT BE RELIED UPON. IN MAKING THE DECISION WHETHER TO INVEST, PROSPECTIVE INVESTORS SHOULD RELY ONLY ON INFORMATION CONTAINED IN THE INFORMATION DOCUMENTS OR IN THE EXHIBITS HERETO. NEITHER THE DELIVERY OF THE INFORMATION DOCUMENTS AT ANY TIME NOR ANY SALE MADE PURSUANT HERETO IMPLIES THAT THE INFORMATION CONTAINED HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE DATE SET FORTH ON THE COVER PAGE HEREOF.

THIS INVESTMENT INVOLVES A HIGH DEGREE OF RISK. (SEE THE RISK FACTORS SECTION OF THE COMPANY’S CONFIDENTIAL OFFERING MEMORANDUM DATED AS OF MARCH 2, 2018 TO WHICH A FORM OF THIS SUBSCRIPTION AGREEMENT IS APPENDED AS APPENDIX A). CONSEQUENTLY, ONLY PERSONS WHO CAN AFFORD A TOTAL LOSS OF THEIR INVESTMENT SHOULD CONSIDER THE PURCHASE OF THE UNITS. SUBSCRIBERS WILL BE REQUIRED TO REPRESENT, AMONG OTHER THINGS, THAT THEY: (A) ARE FULLY FAMILIAR WITH, UNDERSTAND AND CAN BEAR SUCH RISKS; (B) UNDERSTAND ALL OF THE TERMS OF THIS OFFERING; AND; (C) MEET CERTAIN MINIMUM INVESTMENT AND FINANCIAL SOPHISTICATION CRITERIA.

THE INFORMATION DOCUMENTS DO NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN OFFER TO BUY TO ANY PERSON WHO HAS NOT COMPLETED AND RETURNED A SUBSCRIPTION AGREEMENT AND A QUALIFIED PURCHASER QUESTIONNAIRE, OR TO ANY PERSON WHOSE PURCHASER REPRESENTATIVE, IF ANY, HAS NOT COMPLETED AND RETURNED A QUALIFIED PURCHASER REPRESENTATIVE QUESTIONNAIRE, IN FORM AND SUBSTANCE SATISFACTORY TO THE COMPANY AND THE PLACEMENT AGENT.

THE COMPANY IS MAKING THIS OFFERING ONLY TO “ACCREDITED INVESTORS” AS DEFINED UNDER REGULATION D UNDER THE SECURITIES ACT AND MAY, IN ITS SOLE AND ABSOLUTE DISCRETION, REFUSE TO ACCEPT ANY SUBSCRIPTION. THE PRICE OF THE UNITS HAS BEEN ARBITRARILY DETERMINED BY THE COMPANY AND SHOULD NOT BE CONSTRUED AS AN INDICATION OF THE ACTUAL VALUE OF AN EQUITY INTEREST IN THE COMPANY. THE COMPANY RESERVES THE RIGHT TO WITHDRAW OR AMEND THE TERMS OF THIS OFFERING AT ANY TIME IN ITS SOLE AND ABSOLUTE DISCRETION, AND TO REJECT ANY SUBSCRIPTION IN WHOLE OR IN PART.

THE INFORMATION DOCUMENTS DO NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN OFFER TO BUY IN ANY JURISDICTION IN WHICH SUCH SALE OR OFFER OR SOLICITATION WOULD BE PROHIBITED BY LAW.

THE COMPANY HEREBY EXTENDS TO EACH PROSPECTIVE INVESTOR THE OPPORTUNITY TO ASK QUESTIONS OF, AND RECEIVE ANSWERS FROM, ITS OFFICERS CONCERNING THE INFORMATION DOCUMENTS AND TO OBTAIN ANY ADDITIONAL INFORMATION SHE/HE MAY CONSIDER NECESSARY IN MAKING AN INFORMED INVESTMENT DECISION TO THE EXTENT THAT THE COMPANY POSSESSES SUCH INFORMATION OR CAN ACQUIRE IT WITHOUT UNREASONABLE EFFORT OR EXPENSE. ACCESS TO SUCH INFORMATION MAY BE OBTAINED BY DIRECTING REQUESTS TO THE PLACEMENT AGENT AT DIVINE CAPITAL MARKETS LLC, 39 BROADWAY, 36TH FLOOR., NEW YORK, NEW YORK 10006, AND ATTENTION: VIRGINIA DURAN.

THE INFORMATION DOCUMENTS CONTAIN SUMMARIES OF THE TERMS OF CERTAIN DOCUMENTS, BUT REFERENCE IS HEREBY MADE TO THE ACTUAL DOCUMENTS WHICH MAY BE OBTAINED FROM THE COMPANY AT THE ADDRESS SET FORTH BELOW FOR COMPLETE INFORMATION CONCERNING THE RIGHTS AND OBLIGATIONS OF THE PARTIES THERETO. ALL SUCH SUMMARIES ARE QUALIFIED IN THEIR ENTIRETY BY THIS REFERENCE.

NOTICE TO FLORIDA RESIDENTS

THE SECURITIES REFERRED TO HEREIN WILL BE SOLD TO, AND ACQUIRED BY INVESTORS IN A TRANSACTION EXEMPT UNDER SECTION 517.061 OF THE FLORIDA SECURITIES INVESTOR PROTECTION ACT. THE SECURITIES HAVE NOT BEEN REGISTERED UNDER SAID ACT IN THE STATE OF FLORIDA. IN ADDITION, IF SALES ARE MADE TO FIVE OR MORE FLORIDA RESIDENTS, EACH FLORIDA RESIDENT WHO SUBSCRIBES FOR THE PURCHASE OF INTERESTS HEREIN HAS THE RIGHT, PURSUANT TO SECTION 517.061(11)(A)5 OF SAID ACT, TO WITHDRAW SUCH RESIDENT’S SUBSCRIPTION FOR THE PURCHASE WITHIN THREE BUSINESS DAYS AFTER THE EXECUTION AND DELIVERY OF THIS AGREEMENT OR PAYMENT FOR THE SECURITIES HAS BEEN MADE, WHICHEVER IS LATER, AND RECEIVE A FULL REFUND OF ALL MONIES PAID. WITHDRAWAL AND REFUND WILL BE WITHOUT ANY FURTHER LIABILITY TO ANY PERSON. TO ACCOMPLISH THIS WITHDRAWAL, A SUBSCRIBER ONLY NEED SEND LETTER OR FACSIMILE TO THE PLACEMENT AGENT, DIVINE CAPITAL MARKETS LLC, 39 BROADWAY, 36TH FLOOR., NEW YORK, NEW YORK 10006, INDICATING SUCH RESIDENT’S INTENTION TO WITHDRAW. SUCH LETTER MUST BE RECEIVED, PRIOR TO THE END OF THE AFOREMENTIONED THIRD BUSINESS DAY. IT IS PRUDENT TO SEND SUCH LETTER BY CERTIFIED MAIL, RETURN RECEIPT REQUESTED, TO ENSURE THAT IT IS RECEIVED AND ALSO TO EVIDENCE THE TIME IT WAS MAILED, UNLESS SAME IS PERSONALLY DELIVERED. IF THE REQUEST IS MADE VERBALLY IN PERSON OR BY TELEPHONE TO VIRGINIA DURAN AT THE ABOVE ADDRESS, A WRITTEN CONFIRMATION THAT THE REQUEST HAS BEEN RECEIVED SHOULD BE REQUESTED.

THE COMPANY’S ADDRESS IS 701 GATEWAY BOULEVARD, SUITE 210 SOUTH SAN FRANCISCO, CALIFORNIA 94080, ATTENTION: MATTHEW LOAR. ITS TELEPHONE NUMBER IS 650.635.7000.

MATEON THERAPEUTICS, INC.

TABLE OF CONTENTS

Subscription Signature Section EXHIBITS

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SUBSCRIPTION AGREEMENT

AND INVESTMENT LETTER

Date:                      , 2018

To the Board of Directors

Divine Capital Markets LLC 39

Broadway

36 ^th Floor

New York, New York 10006

Attention: Virginia Duran

of Mateon Therapeutics, Inc.

Ladies and Gentlemen:

This Subscription Agreement (this “ Subscription Agreement ”) is being delivered to the purchaser identified on the signature page to this Agreement (the “ Undersigned ” or “ Subscriber ”) in connection with its investment in the securities of Mateon Therapeutics, Inc., a Delaware corporation (the “ Company ”). The Company is conducting a private placement (the “ Offering ”) of a minimum of 20 and a maximum of 80 Units, each of which consists of 250,000 shares of Common Stock of the Company, $0.01 par value per share (the “ Common Stock ”), and warrants (the “ A Warrants ”) to purchase 125,000 shares of Common Stock at an exercise price of $0.40 per share and warrants (the “ B Warrants ”) to purchase 125,000 shares of Common Stock at an exercise price of $0.40 per share (collectively, the “ Warrants ”), at $50,000 per Unit (a “ Unit ”). For purposes of this Agreement, the term “Securities” shall refer to the Units, the Common Stock, the Warrants and the Common Stock to be issued upon the exercise of the Warrants (the “Underlying Shares”).

This will acknowledge that the Subscriber hereby agrees to irrevocably purchase from the Company ___ unit(s) (the “ Units ”) set forth in the Subscription Signature Section below in accordance with the terms of this Subscription Agreement and Investment Letter (the “ Subscription Agreement ”) and pursuant to the terms and conditions set forth in the Confidential Offering Memorandum dated March 2, 2018, including Appendixes attached thereto (the “ Memorandum ”).

1.     Terms of the Offering .

The Offering is being made on a “best efforts, all or none” basis with respect to the first thirty Units, and, thereafter, on a “best efforts only” basis until the remaining 45 Units are sold, the Company terminates the Offering, which it can do in its complete discretion at any time, or the Offering Period, as hereinafter defined, expires, whichever occurs first (the “ Termination Date ”). Unless at least twenty Units (the “Minimum”) are sold on or before March 15, 2018, or April 15, 2018 if extended by the Company and the Placement Agent (the “ Offering Period ”) and paid for with collected funds received in escrow as noted in the next succeeding paragraph within two Business Days thereafter, the Offering will terminate and all funds collected from subscribers will

be promptly returned to them without interest thereon or deduction therefrom. A “Business Day” means any day except Saturday, Sunday and any day that shall be a federal legal holiday or a day on which banking institutions in the State of New York are authorized or required by law or other governmental action to close. Persons affiliated and/or otherwise related to the Company may purchase Units in the Offering and the Units purchased by them will be included in the number of Units needed to satisfy the Minimum. The Placement Agent and persons affiliated with it also may purchase Units in the Offering but the Units purchased by them will not be included in the number of Units needed to satisfy the Minimum.

Because the Minimum of twenty Units must be sold in order to make the Offering effective, all funds received will be held in escrow with JP Morgan Chase Bank (the “ Escrow Agent ”). No funds will be remitted to the Company until at least thirty Units have been sold and paid for. Thereafter, funds will continue to be held in escrow and released to the Company at each subsequent closing, which shall be at the discretion of the Company and the Placement Agent and which shall occur on the earlier of March 15, 2018, which date may be extended to April 15, 2018, by agreement between the Company and the Placement Agent, or when all 80 Units on an accumulative basis have been sold and paid for (each a “ Closing ” and, collectively, the “ Closings ”) against delivery of the appropriate number of subscribed Units. Each Closing of the purchase and sale of the Units following acceptance by the Company of subscriptions, as evidenced by the Company’s execution of the applicable Subscription Agreements, shall take place at the Placement Agent’s offices, or such other place as the Placement Agent and the Company shall determine, on such date as the Placement Agent and the Company shall determine. The date on which a Closing is consummated is the “ Closing Date .”

The Offering is being made only to “accredited investors” as defined under Regulation D under the Securities Act. It is being conducted pursuant to the exemption from the registration provisions of the Securities Act set forth in Section 4(a)(2) thereof and applicable Rules and Regulations promulgated thereunder, including Rule 506 (b) of Regulation D. Section 4(a)(2) requires, among other things, that each purchaser acquire the Units, and Common Stock and the Warrants which are a part thereof, and the Common Stock underlying the Warrants (collectively, the “ Underlying Securities ”) with investment intent and not with a view to distribution. The Units being offered hereby and the Underlying Securities will be “restricted securities” under the Securities Act and may not be resold publicly except in compliance with Rule 144 promulgated thereunder or unless subsequently registered.

Although the Common Stock is traded on the OTCQX Marketplace under the symbol “MATN,” there is no public market for the Units or the Warrants and it is not anticipated that a public trading market for them will ever develop.

As set forth above, the Company has agreed to file a registration statement with the Commission covering the Underlying Securities, but cannot assure that such a filing will be made or, if it is, that it will be declared effective by the Commission. In the event, however, that the registration statement is declared effective, the Company cannot assure that the Underlying Securities will be readily tradable.

ACCORDINGLY, THE UNDERSIGNED UNDERSTANDS AND ACKNOWLEDGES THAT, EVEN AFTER THE TERMINATION OF THE RESALE

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RESTRICTION PERIODS ON THE UNITS AND THE UNDERLYING SECURITIES, AND/OR THE UNDERLYING SECURITIES ARE REGISTERED, SHE/HE MAY BE UNABLE TO RESELL THESE SECURITIES FOR A SIGNIFICANT PERIOD OF TIME, IF EVER.

Execution of this Subscription Agreement shall constitute an offer by the Undersigned to purchase the number of Units set forth in the Subscription Signature Section below on the terms specified herein. If the Undersigned’s offer is accepted, the Company will execute a copy of the Signature Section and return it to the Undersigned.

2.     The Placement Agent .

The Placement Agent, a member firm of the Financial Industry Regulatory Authority (“ FINRA ”), is acting as the exclusive placement agent for the Company in placing this Offering. If all of the Units are sold, the Company will receive gross proceeds of $4,000,000 less the expenses of this Offering. Management estimates that these expenses, including the fee and expense allowance payable to the Placement Agent described below, will be approximately $3,380,000

The Placement Agent will receive a fee equal to 10%, legal and other expenses of up to $25,000 and a non-accountable expense allowance equal to 3% of the aggregate gross purchase price of the Units sold. The Company will also grant to the Placement Agent, for nominal consideration, a warrant, exercisable over a five year period commencing on the final Closing Date of the Offering, to purchase such number of Units as shall equal 10% of the number of Units sold in the Offering at an exercise price equal to 100% of the Unit offering price, which is equivalent to $0.20 per share.

The undersigned understands that, except as may be required by applicable regulations of FINRA, the Placement Agent has not independently verified the information provided to her/him with respect to the Company. Accordingly, there is no representation by the Placement Agent as to the completeness or accuracy of such information.

3.     Suitability Requirements; Transferability .

An investment in the Company involves a high degree of risk and is suitable only for those qualified persons who have substantial financial resources and who, alone or together with their purchaser representatives (see the definition below), have such knowledge and experience in financial and business matters that they are capable of evaluating the merits and risks of purchasing the Units. Satisfaction of these suitability standards by a person does not represent a determination by the Company that the Units are a suitable investment for such person. Each person must consult such person’s own professional advisors in order to determine the suitability of the investment. The Company may make or cause to be made such further inquiry and obtain such additional information as it deems appropriate with regard to the suitability of prospective investors.

Because this Offering is being made only to accredited investors, the Undersigned must complete, sign and return a Purchaser Questionnaire to the Company in order to assist it in determining whether the Undersigned is an accredited or sophisticated investor and satisfies the minimum suitability requirements. The form of Purchaser Questionnaire is attached hereto as Appendix D.

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The term “purchaser representative” means any person who satisfies all of the following conditions or who the Company reasonably believes satisfies all of the following conditions:

(a)    she/he is not an affiliate, director, officer or other employee of the Company or beneficial owner of 10% or more of any class of the Company’s equity securities, except where the purchaser is:

(i)    A relative of the purchaser representative by blood, marriage or adoption and not more remote than a first cousin;

(ii)    A trust or estate in which the purchaser representative and any persons related to her/him as specified in Paragraph (h)(1)(i) or (h)(1)(iii) of Rule 501 under Regulation D, collectively have more than 50 percent of the beneficial interest (excluding contingent interest) or of which the purchaser representative serves as trustee, executor, or in any similar capacity; or

(iii)    A corporation or other organization of which the purchaser representative and any persons related to her/him as specified in Paragraph (h)(1)(i) or (h)(1)(ii) of Rule 501, collectively are the beneficial owners of more than 50 percent of the equity securities (excluding directors’ qualifying shares) or equity interests;

(b)    she/he has such knowledge and experience in financial and business matters that she/he is capable of evaluating, alone, or together with other purchaser representatives of the purchaser or together with the purchaser, the merits and risks of the prospective investment;

(c)    she/he is acknowledged by the purchaser in writing, during the course of the transaction, to be her/his purchaser representative in connection with evaluating the merits and risks of the prospective investment; and

(d)    she/he discloses to the purchaser in writing prior to the acknowledgment specified in Paragraph (h)(3) of Rule 501, any material relationship between herself/himself or her/his affiliates and the Company or its affiliates that then exists, that is mutually understood to be contemplated or that has existed at any time during the previous two years and any compensation received or to be received as a result of such relationship.

If the Undersigned is using a purchaser representative, the purchaser representative must complete, execute and return a Purchaser Representative’s Questionnaire to the Company. A form of Purchaser Representative’s Questionnaire is attached hereto as Appendix D.

4.     Subscription Procedure and Effect .

The subscription price shall be payable upon execution of this Subscription Agreement in accordance with the terms set forth herein. In order to subscribe for the Units, a qualified prospective investor must deliver the following to the Placement Agent, at 39 Broadway, 36th Floor, New York, New York 10006, Attention Virginia Duran.

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a certified check, bank draft or money order, in the amount of the purchase price for the Units to be purchased, payable to JP Morgan Chase Bank for “Mateon Therapeutics, Inc.” Wired funds are also acceptable. The Company would prefer that the funds be wired. The wiring instructions are: JP Morgan Chase Bank; ACCOUNT NAME: DCM for exclusive benefit of investors of Mateon Therapeutics; ACCOUNT NUMBER: 365 227 2809; ROUTING NUMBER: 021 000 021.

On delivery of the executed Subscription Signature Section of this Subscription Agreement, the Subscriber will become bound by its terms. Unless otherwise required by applicable state securities laws, the Subscriber may not withdraw or revoke her/his executed Subscription Agreement in whole or in part without the consent of the Company.

The Company may accept this Subscription Agreement at any time on or before the Termination Date. This Subscription Agreement is not binding on the Company until it is accepted as evidenced by the signature of an officer of the Company. The Company, in its sole discretion, has the right to accept or reject this Subscription Agreement in whole or in part and accept Subscription Agreements other than in the order received. In the event of rejection of this Subscription Agreement, or in the event that, for any reason, none of the Units are sold (in which case this Subscription Agreement will be deemed to be rejected), the Company will thereafter promptly return or cause to be returned to the Subscriber by mail, a check in the amount paid by the Subscriber in this Offering, without interest thereon or deduction therefrom for expenses or otherwise, and this Subscription Agreement shall thereafter have no further force or effect except for the provisions of Section  7 .

5.     The Company ’ s Representations, Warranties and Covenants . The Company represents, warrants and covenants to the Undersigned and the Placement Agent that:

(a)     Subsidiaries . The Company has no direct or indirect subsidiaries other than those set forth in the SEC Documents, as defined below in Subsection 5(e) , (individually a “ Subsidiary ” and, collectively, the “ Subsidiaries ”). Except as disclosed in the SEC Documents, the Company owns, directly or indirectly, all of the capital stock of each Subsidiary free and clear of any and all liens, charges, encumbrances, security interests, rights of first refusal or other restrictions of any kind (each a “ Lien ” and, collectively, “ Liens ”), and all the issued and outstanding shares of capital stock of each Subsidiary are validly issued and are fully paid, non-assessable and free of preemptive and similar rights.

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(b)     Organization and Qualification . Each of the Company and each Subsidiary is an entity duly incorporated or otherwise organized, validly existing and in good standing under the laws of the jurisdiction of its incorporation or organization (as applicable), with the requisite power and authority to own and use its properties and assets and to carry on its business as currently conducted. Neither the Company nor any Subsidiary is in violation of any of the provisions of its respective certificate or articles of incorporation, bylaws or other organizational or charter documents. Each of the Company and each Subsidiary is duly qualified to conduct business and is in good standing as a foreign corporation or other entity in each jurisdiction in which the nature of the business conducted or property owned by it makes such qualification necessary, except where the failure to be so qualified or in good standing, as the case may be, could not, individually or in the aggregate, have or reasonably be expected to result in (i) an adverse effect on the legality, validity or enforceability of any agreement or other document executed by the Company relating to the Offering (each a “ Transaction Document ” and, collectively, the “ Transaction Documents ”), (ii) a material and adverse effect on the results of operations, assets, prospects, business or condition (financial or otherwise) of the Company and the Subsidiaries, taken as a whole, or (iii) an adverse impairment to the Company’s ability to perform on a timely basis its obligations under any Transaction Document (any of (i), (ii) or (iii), a “ Material Adverse Effect ”).

(c)     Authorization; Enforcement . The Company has the requisite corporate power and authority to enter into and to consummate the transactions contemplated by each of the Transaction Documents and otherwise to carry out its obligations thereunder. The execution and delivery of each of the Transaction Documents by the Company and the consummation by it of the transactions contemplated thereby have been duly authorized by all necessary corporate action on the part of the Company and no further corporate action is required by the Company in connection therewith. Each Transaction Document has been (or upon delivery will have been) duly executed by the Company and, when delivered in accordance with the terms hereof, will constitute the valid and binding obligation of the Company enforceable against the Company in accordance with its terms, except as rights to indemnity and contribution may be limited by state or federal securities laws or the public policy underlying such laws, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ and contracting parties’ rights generally and except as enforceability may be subject to general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law).

(d)     No Conflicts . The execution, delivery and performance of the Transaction Documents by the Company and the consummation by the Company of the transactions contemplated thereby do not and will not (i) conflict with or violate any provision of the Company’s or any Subsidiary’s certificate or articles of incorporation, bylaws or other organizational or charter documents, or (ii) conflict with, or constitute a default (or an event that with notice or lapse of time or both would become a default) under, or give to others any rights of termination, amendment, acceleration or cancellation (with or without notice, lapse of time or both) of, any agreement, credit facility, debt or other instrument (evidencing a Company or Subsidiary debt or otherwise) or other understanding to which the Company or any Subsidiary is a party or by which any property or asset of the Company or any Subsidiary is bound or affected, or (iii) result in a violation of any law, rule, regulation, order, judgment, injunction, decree or other restriction of any court or governmental authority to which the Company or a Subsidiary is subject (including federal and state securities laws and regulations), or by which any property or asset of the Company or a Subsidiary is bound or affected; except in the case of each of clauses (ii) and (iii), such as could not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect.

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(e)     Representations and Warranties relating to the SEC Documents . The Company has filed all reports, schedules, forms, statements and other documents (collectively, the “ SEC Documents ”) required to be filed by it with the Commission pursuant to the Securities Exchange Act of 1934 (the “ Exchange Act ”), in a timely manner within the past three years. The SEC Documents have complied in all material respects with the requirements of the Exchange Act and the rules and regulations of the Commission promulgated thereunder applicable to the SEC Documents, and none of the SEC Documents, at the time they were filed with the Commission, contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. As of their respective dates, to the best of the Company’s knowledge during those respective dates, the Company’s financial statements included in the SEC Documents complied as to form in all material respects with applicable accounting requirements and the published rules and regulations of the Commission with respect thereto. Such financial statements have been prepared in accordance with accounting principles generally accepted in the United States as in effect from time to time, consistently applied (“ GAAP ”), during the periods involved (except (a) as may be otherwise indicated in such financial statements or the notes thereto, or (b) in the case of unaudited interim statements, to the extent they may exclude footnotes or may be condensed or summary statements) and fairly present in all material respects the Company’s financial condition as of the respective dates thereof and the results of the Company’s operations and cash flows for the respective periods then ended (subject, in the case of unaudited statements, to normal year- end audit adjustments). The Company has not received notification from the Commission, and/or any federal or state securities bureaus that any investigation (informal or formal), inquiry or claim is pending, threatened or in process against the Company and/or relating to any of its securities.

(f)     Material Changes . Since the date of the latest audited financial statements included within the SEC Documents, except as specifically disclosed in the SEC Documents, (i) there has been no event, occurrence or development that has had or is reasonably likely to result in a Material Adverse Effect, (ii) the Company has not incurred any liabilities (contingent or otherwise) other than (A) trade payables and accrued expenses incurred in the ordinary course of business consistent with past practice, and (B) liabilities not required to be reflected in the Company’s financial statements pursuant to GAAP or required to be disclosed in filings made with the Commission, (iii) the Company has not altered its method of accounting or the identity of its auditors, (iv) the Company has not declared or made any dividend or distribution of cash or other property to its stockholders or purchased, redeemed or made any agreements to purchase or redeem any shares of its capital stock, and (v) the Company has not issued any equity securities to any officer, director or affiliate, except pursuant to existing Company stock option or stock purchase plans or disclosed in SEC Documents. Except as specified in the SEC Documents, the Company does not have pending before the Commission any request for confidential treatment of information.

(g)     Litigation . Except as disclosed in the SEC Documents, (i) there is no action, suit, inquiry, notice of violation, proceeding (including any partial proceeding such as a deposition) or investigation pending or threatened in writing against or affecting the Company, any Subsidiary

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or any of their respective properties before or by any court, arbitrator, governmental or administrative agency, regulatory authority (federal, state, county, local or foreign), stock market, stock exchange or trading facility (individually an “ Action ” and, collectively, “ Actions ”), which (A) adversely affects or challenges the legality, validity or enforceability of any of the Transaction Documents or the Units or Underlying Securities or (B) could, if there were an unfavorable decision, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect, (ii) neither the Company nor any Subsidiary, nor any director or officer thereof, is or has been the subject of any Action involving a claim of violation of or liability under federal or state securities laws or a claim of breach of fiduciary duty, and (iii) there has not been, and to the knowledge of the Company, there is not pending or contemplated, any investigation by the Commission involving the Company or any current or former director or officer of the Company. The Commission has not issued any stop order or other order suspending the effectiveness of any registration statement filed by the Company or any Subsidiary under the Exchange Act or the Securities Act.

(h)     Employment Matters . The Company and the Subsidiaries are in compliance with all federal, state, local and foreign laws and regulations respecting employment and employment practices, terms and conditions of employment and wages and hours except where failure to be in compliance would not have a Material Adverse Effect. Neither the Company nor any Subsidiary is bound by or subject to (and none of the Company’s or any of its Subsidiaries’ assets or properties are bound by or subject to) any written or oral, express or implied, contract, commitment or arrangement with any labor union, and no labor union has requested or, to the Company’s knowledge, has sought to represent any of the employees, representatives or agents of the Company or the Subsidiaries. There is no strike or other material labor dispute involving the Company or the Subsidiaries pending, or to the Company’s knowledge, threatened, that could have a Material Adverse Effect nor is the Company aware of any labor organization activity involving its or its Subsidiaries’ employees. The Company is not aware that any officer or key employee intends to terminate her or his employment with the Company, nor does the Company have a current intention to terminate the employment of any officer or key employee.

(i)     Compliance . Neither the Company nor any Subsidiary (i) is in default under or in violation of (and no event has occurred that has not been waived that, with notice or lapse of time or both, would result in a default by the Company or any Subsidiary under), nor has the Company or any Subsidiary received notice of a claim that it is in default under or that it is in violation of, any indenture, loan or credit agreement or any other agreement or instrument to which it is a party or by which it or any of its properties is bound (whether or not such default or violation has been waived), (ii) is in violation of any order of any court, arbitrator or governmental body, or (iii) is or has been in violation of any statute, rule or regulation of any governmental authority, including without limitation all foreign, federal, state and local laws relating to taxes, environmental protection, occupational health and safety, product quality and safety and employment, labor matters and gaming matters, except in each case as could not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect. The Company is in compliance with the applicable requirements of the Sarbanes-Oxley Act of 2002 and the rules and regulations thereunder promulgated by the Commission, except where such noncompliance could not have or reasonably be expected to result in a Material Adverse Effect.

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(j)     Regulatory Permits . The Company and the Subsidiaries possess all certificates, authorizations and permits issued by the appropriate federal, state, local or foreign regulatory authorities necessary to conduct their respective businesses as described in the SEC Documents, except where the failure to possess such permits would not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect (each a “ Material Permit ”), and neither the Company nor any Subsidiary has received any notice of proceedings relating to the revocation or modification of any Material Permit.

(k)     Title to Assets . The Company and the Subsidiaries have good and marketable title in all personal property owned by them that is material to their respective businesses, in each case free and clear of all Liens. Any real property and facilities held under lease by the Company and the Subsidiaries are held by them under valid, subsisting and, to the Company’s knowledge, enforceable leases of which the Company and the Subsidiaries are in compliance, except as could not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect.

(l)     Patents and Trademarks . The Company and the Subsidiaries have, or have rights to use, all patents, patent applications, trademarks, trademark applications, service marks, trade names, copyrights, licenses and other similar rights that are necessary or material for use in connection with their respective businesses as described in the SEC Documents and which the failure to so have could, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect (collectively, the “ Intellectual Property Rights ”). Neither the Company nor any Subsidiary has received a written notice that the Intellectual Property Rights used by the Company or any Subsidiary violates or infringes upon the rights of any individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind (a “ Person ”). To the knowledge of the Company, all such Intellectual Property Rights are enforceable and there is no existing infringement by another Person of any of the Intellectual Property Rights.

(m)     Insurance . The Company and the Subsidiaries are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which the Company and the Subsidiaries are engaged. The Company does not believe that it will be unable to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business without a material increase in cost.

(n)     Transactions With Affiliates and Employees . Other than set forth in the SEC Documents, none of the officers or directors of the Company and, to the knowledge of the Company, none of the employees of the Company is currently a party to any transaction with the Company or any Subsidiary (other than for services as employees, officers and directors), including any contract, agreement or other arrangement providing for the furnishing of services to or by, providing for rental of real or personal property to or from, or otherwise requiring payments to or from any officer, director or such employee or, to the knowledge of the Company, any entity in which any officer, director, or any such employee has a substantial interest or is an officer, director, trustee or partner.

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(o)     Internal Accounting Controls . The Company and the Subsidiaries maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations, (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability, (iii) access to assets is permitted only in accordance with management’s general or specific authorization, and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(p)     Certain Fees . Except for transactions with the Placement Agent, no brokerage or finder’s fees or commissions are or will be payable by the Company to any broker, financial advisor or consultant, finder, placement agent, investment banker, bank or other Person with respect to the transactions related to the Offering.

(q)     Investment Company . The Company is not, and is not an affiliate of, an “investment company” within the meaning of the Investment Company Act of 1940.

(r)     Taxes . The Company and the Subsidiaries have timely made or filed all federal, state and foreign income and all other tax returns, reports and declarations required by any jurisdiction to which the Company or such Subsidiaries are subject (unless and only to the extent that the Company or such Subsidiaries have set aside on their books provisions reasonably adequate for the payment of all unpaid and unreported taxes) and have timely paid all taxes and other governmental assessments and charges that are material in amount, shown or determined to be due on such returns, reports and declarations, except those being contested in good faith, and have set aside on their books provisions reasonably adequate for the payment of all taxes for periods subsequent to the periods to which such returns, reports or declarations apply. To the Company’s knowledge, there are no unpaid taxes of the Company and the Subsidiaries in any material amount claimed to be due by the taxing authority of any jurisdiction. Neither the Company nor the Subsidiaries have executed a waiver with respect to the statute of limitations relating to the assessment or collection of any foreign, federal, state or local tax. None of the Company’s or any of its Subsidiaries’ tax returns is currently being audited by any taxing authority.

(s)     Disclosure . The Company confirms that neither it, nor to its knowledge, any other Person acting on its behalf has provided any prospective purchasers of the Securities or their agents or counsel with any information that the Company believes constitutes material, non-public information. The Company understands and confirms that the prospective purchasers will rely on the foregoing representations and covenants in effecting transactions in securities of the Company. All disclosure provided to the prospective purchasers regarding the Company, its business and the transactions contemplated hereby, furnished by or on behalf of the Company (including the Company’s representations and warranties set forth in this Subscription Agreement) are true and correct in all material respects and do not contain any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements made therein, in light of the circumstances under which they were made, not misleading.

(t)     Foreign Corrupt Practices . Neither the Company, nor to the knowledge of the Company, any agent or other Person acting on behalf of the Company, has (i) directly or indirectly, used any funds for unlawful contributions, gifts, entertainment or other unlawful expenses related

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to foreign or domestic political activity, (ii) made any unlawful payment to foreign or domestic government officials or employees or to any foreign or domestic political parties or campaigns from corporate funds, (iii) failed to disclose fully any contribution made by the Company (or made by any Person acting on its behalf of which the Company is aware) which is in violation of law, or (iv) violated in any material respect any provision of the Foreign Corrupt Practices Act of 1977, as amended.

(u)    The Company will seek shareholder approval for an increase in the number of shares of its authorized common stock, at its annual shareholder meeting to be held in 2018, to allow for the full exercise of all Warrants to be issued as part of the Units.

6.     Validity of Securities . The Company represents and warrants to the Undersigned that the Units and the shares of Common Stock being sold as part of the Units have been duly authorized and, when issued and paid for in accordance with the terms of the Transaction Documents, will be duly and validly issued, fully paid and nonassessable and free and clear of all liens, other than restrictions on transfer provided for in the Transaction Documents or imposed by applicable securities laws, and shall not be subject to preemptive or similar rights of stockholders. The Warrants have been duly authorized, and, when issued and paid for in accordance with the terms of the Transaction Documents, will be duly and validly issued, free and clear of all Liens, other than restrictions on transfer provided for in the Transaction Documents or imposed by applicable securities laws, and shall not be subject to preemptive or similar rights of stockholders. The shares of Common Stock issuable upon exercise of the A Warrants have been duly authorized and the shares of Common Stock issuable upon exercise of the B Warrants will be duly authorized, and when issued and paid for in accordance with the terms of the Transaction Documents and the Warrants, will be duly and validly issued, fully paid and nonassessable, free and clear of all Liens, other than restrictions on transfer provided for in the Transaction Documents or imposed by applicable securities laws, and shall not be subject to preemptive or similar rights of stockholders. Assuming the accuracy of the representations and warranties of the Purchasers in this Agreement, the Securities will be issued in compliance with all applicable federal and state securities laws.

7.     Indemnity . The Subscriber agrees to indemnify and hold harmless the Company, the Placement Agent, and their respective officers, directors, employees, attorneys and agents, and any other Persons authorized by the Company to participate in the offer and/or sale of the Units against any and all loss, liability, claim, damage and expenses (including, but not limited to, any and all expenses reasonably incurred in investigating, preparing or defending against litigation commenced or threatened or any claim whatsoever) arising out of or based upon any breach of or failure by the Subscriber to comply with any representation, warranty, covenant or agreement made by the Subscriber herein or in any other document furnished by the Subscriber to any of the foregoing in connection with this transaction.

8.     Support for Common Stock Increase . The Purchaser agrees to vote any shares of Common Stock held by the Purchaser as of the date of the Company’s next stockholder meeting in favor of the increase in the authorized number of shares of Common Stock as contemplated in the B Warrants.

9.     Representation and Covenant Relating to Short Sales . The Purchaser represents that she/he has never held a short position in the Company’s Common Stock and covenants that she/he will never short the Common Stock as long as she/he owns the Common Stock or securities convertible into shares of the Company’s Common Stock.

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10.     Modification . Neither this Subscription Agreement nor any provisions hereof shall be modified, changed, discharged or terminated except by an instrument in writing signed by the party against whom any waiver, change, discharge or termination is sought.

11.     Notices . All notices, consents, requests, demands, offers, reports and other communications required or permitted to be given pursuant to this Subscription Agreement shall be in writing and shall be considered properly given or made when personally delivered to the party entitled thereto, or when sent by a nationally recognized overnight delivery service, confirmed electronic or facsimile transmission, or by United States mail in a sealed envelope, with postage prepaid, addressed, if to the Company, to the address given above, and if to the Subscriber, to the address set forth opposite the Subscriber’s signature on the counterpart of this Subscription Agreement that the Subscriber originally executes and delivers to the Company. The Company may change its address by giving notice thereof to all Unit purchasers.

12.     Counterparts . This Subscription Agreement may be executed in multiple counterpart copies, each of which shall be considered an original and all of which shall constitute one and the same instrument binding on all the parties, notwithstanding that all parties are not signatures to the same counterpart.

13.     Successors and Assigns . This Subscription Agreement and all of the terms and provisions hereof shall be binding upon and inure to the benefit of the parties and their respective heirs, executors, administrators, successors, trustees, legal representatives and assigns. If the Subscriber is more than one person, the obligation of the Subscriber shall be joint and several and the agreements, representations, warranties and acknowledgments herein contained shall be deemed to be made by and be binding upon each such person and her/his heirs, executors, administrators, successors, trustees, legal representatives and assigns.

14.     Transferability . The Undersigned may not transfer or assign this Subscription Agreement or any interest of the Undersigned’s herein and any attempt to effect such a transfer shall be void. The assignment and transferability of the Units and Underlying Securities acquired by the Undersigned pursuant hereto shall be made only in accordance with the provisions of this Subscription Agreement, the Securities Act and the Rules and Regulations promulgated thereunder and applicable state securities laws.

15.     Applicable Law . This Subscription Agreement shall be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed entirely within such State.

16.     Gender . The use herein of the masculine pronouns or similar terms shall be deemed to include the feminine and neuter genders as well and vice versa and the use of the singular pronouns shall be deemed to include the plural as well and vice versa.

17.     Severability . If one or more of the provisions or portions of this Subscription Agreement shall be deemed by any court or quasi-judicial authority to be invalid, illegal or unenforceable in any respect, the invalidity, illegality or unenforceability of the remaining provisions, or portions of provisions contained herein shall not in any way be affected or impaired thereby.

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SUBSCRIPTION SIGNATURE SECTION

MATEON THERAPEUTICS, INC.

MARCH 2, 2018

SUBSCRIPTION AGREEMENT AND INVESTMENT LETTER

The undersigned (the “ Undersigned ” or “ Subscriber ”) hereby purchases ____ Units from Mateon Therapeutics, Inc. (the “ Company ”) pursuant to the terms of the Subscription Agreement dated March 2, 2018 (the “ Subscription Agreement ”) of which this Subscription Signature Section is a part. All terms in this Subscription Signature Section have the meanings defined elsewhere in this Subscription Agreement.

Subscriber Representations .

The Subscriber hereby acknowledges, represents and warrants to, and agrees with the Company as follows:

(a)    The Subscriber is acquiring the Units and Underlying Securities for the Subscriber’s own account as principal for investment and not with a view to resale, distribution or fractionalization in whole or in part, and has no current agreement, understanding or arrangement to subdivide, sell, assign or otherwise dispose of all or any part of the Units and/or Underlying Securities and understands that there is no public market for the Units or Warrants, and none is expected to develop in the foreseeable future, if ever. She/he does not have any contract, undertaking, agreement or arrangement with any Person to sell, transfer or grant participations to such Person or to any third Person, with respect to the Units and/or Underlying Securities for which she/he is subscribing.

(b)    The Units and Underlying Securities that the Subscriber is purchasing and the Underlying Securities into which the Warrants may be exercised have not been registered under the Securities Act or qualified under applicable state securities laws and the registration provisions of the Securities Act as well as the qualification provisions of such state laws thereof restrict their transferability. Based upon the representations and agreements being made by her/him herein, the Subscriber acknowledges that the offering and sale of the Units are intended to be exempt from registration under the Securities Act by virtue of Section 4(a)(2) thereof and applicable Rules and Regulations adopted thereunder, and that:

1.    the Undersigned’s Units and Underlying Securities cannot be sold, pledged, assigned or otherwise disposed of unless they are subsequently registered under the Securities Act or qualified under applicable state securities laws or, in the reasonable opinion of the Company’s counsel, an exemption from such registration and/or qualification is available;

2.    Sales or transfers of the Undersigned’s Units and Underlying Securities are further restricted by the provisions of state securities laws;

3.    the Company is under no obligation to assist the Undersigned in complying with any exemption from registration under the Securities Act or qualification under any state securities law, or, except as may be provided in the Registration Rights Agreement, to register the Units or Underlying Securities on the Undersigned’s behalf;

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4.    the certificates or other documentation representing the Undersigned’s Underlying Securities will bear, in substance, the following legend:

These securities have not been registered under the Securities Act of 1933. They may not be sold or transferred in the absence of an effective Registration Statement under that Act without an opinion of counsel satisfactory to the Company that such Registration is not required. ;

5.    the Company will place stop-transfer instructions on its books and with the transfer agent of its securities with respect to the Units and Underlying Securities registered in the name of the Undersigned or beneficially owned by her/him.

The Undersigned further acknowledges that the basis for these exemptions may not be available if, notwithstanding such representations, she/he only intends to hold these securities for a fixed or determinable period in the future, or until the market price rises or falls and she/he hereby represents and warrants that she/he does not have any such intention.

(c)    The Subscriber: (A) by herself/himself or together with her/his Purchaser Representative, if any, has such knowledge and experience in financial, business and tax matters that she/he is capable of evaluating the merits of the prospective purchase of the Units and making an investment decision with respect to the Company; (B) has had substantial experience in previous private and public purchases of speculative securities and is not relying on the Company, the Placement Agent, or any of their respective affiliates or attorneys with respect to economic, tax or other considerations involved in this investment; and (C) is able to bear the economic risk of this investment ( i . e ., she/he can afford a complete loss of her/his investment). In this regard, her/his overall commitment to investments, which are not readily marketable, is not disproportionate to her/his net worth, and her/his purchase of the Units will not cause such overall commitment to become excessive.

(d)    The Subscriber understands and acknowledges that an investment in the Company is speculative and subject to many risks. In this regard, the Company cannot assure her/him that all of the Units will be sold. Accordingly, the Company’s operations and financial condition will be adversely affected to the extent that less than all of the Units are sold, especially because it currently has no commitment for any financing.

(e)                          (insert name of Purchaser Representative: if none, leave blank) has acted as the Undersigned’s Purchaser Representative for purposes of the private placement exemption under the Securities Act. If the Undersigned has appointed a Purchaser Representative (which term is used herein with the same meaning as given in Rule 501(h) of Regulation D), she/he has been advised by her/his Purchaser Representative as to the merits and risks of an investment in the Company in general and the suitability of the Units as an investment for the Undersigned in particular, and is aware that the Purchaser Representative may be receiving compensation from the Company in connection with the services being performed by such Purchaser Representative for the Undersigned relating to her/his purchase of the Units.

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(f)    The Subscriber has reviewed carefully the definition of “accredited investor” as set forth below, and the particular subparagraph or subparagraphs by which the Undersigned qualifies as such is (are) checked by her/him below.

(g)    The Subscriber has carefully reviewed the Confidential Offering Memorandum dated March 2, 2018 including the Risk Factors section set forth therein and in the SEC Documents

THE UNDERSIGNED UNDERSTANDS THAT, BECAUSE OF THE SIGNIFICANT RISK FACTORS SET FORTH IN THE CONFIDENTIAL OFFERING MEMORANDUM AND IN THE SEC DOCUMENTS, INCLUDING BUT NOT LIMITED TO THE RISK FACTORS SET FORTH IN THE DESCRIPTION OF RISK FACTORS DISCLOSED IN THE CONFIDENTIAL OFFERING MEMORANDUM AND THE SEC DOCUMENTS, IF THE OFFERING IS CONSUMMATED, SHE/HE COULD LOSE HER/HIS ENTIRE INVESTMENT.

(balance of this page left blank intentionally)

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Definition of Accredited Investor

The Undersigned represents that she/he is an “accredited investor” as that term is defined in Rule 501 (a) of Regulation D promulgated under the Securities Act as follows (CHECK APPLICABLE BOXES):

☐    (A)    Certain banks, savings and loan institutions, broker-dealers, investment companies and other entities including an employee benefit plan within the meaning of Title I of the Employee Retirement Income Security Act of 1974 with total assets in excess of $5,000,000; any private business development company as defined in Section 202 (a) (22) of the Investment Advisers Act of 1940; any organization described in Section 501 (c) (3) of the Internal Revenue Code, corporation, Massachusetts or similar business trust, or partnership, not formed for the specific purpose of acquiring the Units, with total assets in excess of $5,000,000; or any trust with total assets in excess of $5,000,000 not formed for the specific purpose of acquiring the securities offered, whose purchase is directed by a sophisticated person as described in Section 230.506 (b) (2) (ii) of Regulation D;

☐    (B)    Any natural person whose individual net worth, or joint net worth with that person’s spouse, at the time of her/his purchase exceeds $1,000,000 excluding the value of that person’s personal residence;

☐    (C)    Any natural person who had an individual income in excess of $200,000 or, with that person’s spouse a joint income in excess of $300,000 in each of the two most recent years and who reasonably expects an income in excess of $200,000, or $300,000 with that person’s spouse, in the current year;

☐    (D)    Any Individual Retirement Account and the individual who established the IRA is an accredited investor on the basis of (B) or (C) above;

☐    (E)    Any director, executive officer or general partner of the issuer of the securities being offered or sold, or any director, executive officer or general partner of a general partner of that issuer; or

☐    (F)    Any entity in which all of the equity owners are accredited investors under any of the paragraphs above.

In connection with the foregoing representations the Undersigned has appended hereto as Appendix E, a Purchaser Questionnaire that she/he has completed and executed. She/he represents and warrants that the information set forth therein as well as all other information which she/he is furnishing to the Company with respect to her/his financial condition and business and investment experience is accurate and complete as of the date hereof and she/he covenants that, in the event a material change should occur in such information, she/he will immediately provide the Company with such revised or corrected information.

(h)    The Subscriber has adequate means of providing for her/his current needs and possible personal contingencies, has no need for liquidity of this investment and has no reason to anticipate any change in personal circumstances, financial or otherwise, which might cause or require any sale or distribution of the Units and/or Underlying Securities.

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(i)    The Subscriber is familiar with the nature of the risks attending investments in securities and has determined that the purchase of the Units is consistent with her/his investment objectives and income prospects.

(j)    The Subscriber’s purchase of the Units has not been solicited by means of general solicitation or general advertisement, and the Subscriber has not been furnished with any oral representation or oral information in connection with the Offering which is not set forth in the Confidential Offering Memorandum or herein or in the Exhibits thereto or hereto or in the SEC Documents.

(k)    The Subscriber has received, reviewed and understands the Confidential Offering Memorandum and this Subscription Agreement, including all of the Exhibits attached thereto and hereto, has reviewed the SEC Documents, and has been granted a reasonable time prior to the date hereof during which she/he has had the opportunity to obtain such additional information as she/he deemed necessary to permit her/him to make an informed decision with respect to the purchase of her/his Units. She/he also represents and warrants that she/he (A) has reviewed such other documents and obtained such other information from the Company as she/he deems necessary in order for her/him to make an informed investment decision; (B) has had access to all relevant documents, instruments, books, and other records of or pertaining to the Company and has had the opportunity to ask questions of and receive answers from management and other representatives of the Company and requires no additional information or documentation; and (C) is fully aware of the current business prospects, financial condition, and operating history as set forth herein and in the Exhibits to the Confidential Offering Memorandum and hereto and in the SEC Documents relating to the Company.

(l)    Other than information given to the Subscriber as described in Paragraph (k)  above, no representations or warranties have been made to the Undersigned by the Company, the Placement Agent or any other Person in connection with this Offering, or any officer, employee, agent or affiliate of the Company or the Placement Agent, other than the representations made by the Company set forth I the Confidential Offering Memorandum or herein and she/he is not relying upon any representations other than those described in Paragraph (k)  above.

(m)    The Subscriber is not relying on the Company, the Placement Agent or this Subscription Agreement with respect to individual tax and other economic considerations involved in this investment and acknowledges that her/his investment in the Company is not a tax shelter.

(n)    If for any reason this Offering does not close or the Company does not accept the Undersigned’s subscription, the Undersigned shall have no claims against the Company, the Placement Agent, or their respective officers, directors, employees, attorneys or affiliates, and shall have no interest in the Units, the Underlying Securities or the Company.

(o)    If the Subscriber is a corporation, limited liability company, partnership, trust or other entity: (A) it is authorized and qualified to become a stockholder in, and authorized to make its investment in, the Company as provided herein; (B) it was not formed for the purpose of purchasing the Units; (C) the person signing this Subscription Agreement on behalf of such entity has been duly authorized by such entity to do so and by her/his execution of the Subscription Agreement, the Subscription Agreement constitutes a valid and legally binding obligation by the Subscriber; and (D) the Undersigned is duly organized and validly existing under the laws of its state of organization.

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(p)    If the Subscriber is an individual, she/he is over 21 years of age; or, if the Subscriber is a partnership, trust or other entity, each equity owner of such entity is over 21 years of age.

(q)    The Undersigned has full power and authority to enter into this Subscription Agreement and, upon execution by the Undersigned, the Subscription Agreement will constitute the Undersigned’s valid and legally binding obligation.

(r)    This Subscription Agreement, together with the Exhibits hereto, constitutes the entire agreement of the parties hereto, and supersedes all prior understandings with respect to the subject matter hereof.

(s)    The address set forth below is the Undersigned’s (if an individual) true and correct residence, and the Undersigned has no current intention of becoming a resident of any other state or jurisdiction prior to the date on which payment in full for her/his Units will be made. If the Undersigned is a partnership, corporation or other entity, such address is such entity’s principal place of business.

(t)    All information which the Subscriber has heretofore furnished to the Company in this Subscription Agreement or any Exhibits thereto, is correct and complete as of the date of this Subscription Agreement and if there should be any material change in such information prior to her/his purchase of the Units she/he will immediately furnish such revised or corrected information to the Company.

(u)    The foregoing representations, warranties and agreements shall survive the date of this Subscription Agreement and the final Closing of the Offering.

THE UNDERSIGNED ACKNOWLEDGES THAT THIS SUBSCRIPTION AGREEMENT CONSISTS OF 25 PAGES AND ALSO INCLUDES APPENDICES A THROUGH F WHICH ARE PART OF THE MEMORANDUM ATTACHED AS EXHIBIT A.

(Subscription Page to follow)

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Subscription Page

PLEASE GIVE THE EXACT AND COMPLETE NAME IN WHICH TITLE TO THE UNITS ARE TO BE HELD:

(signature page to follow)

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Signature Page

IN WITNESS WHEREOF, the Purchaser has executed this Subscription Agreement on the          day of                      , 2018.

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Exhibit 10.2

REGISTRATION RIGHTS AGREEMENT

This Registration Rights Agreement (this “ Agreement ”) is made and entered into as of April 12, 2018, by and among Mateon Therapeutics, Inc., a Delaware corporation with offices at 701 Gateway Boulevard, Suite 210, South San Francisco, California 94080, and the investors signatory hereto (each a “ Purchaser ” and collectively, the “ Purchasers ”). This Agreement is made pursuant to the Subscription Agreement and Investment Letter, dated as of the date hereof, executed by each of the Purchasers and the Company (the “ Subscription Agreement ”).

NOW, THEREFORE, IN CONSIDERATION of the mutual covenants contained in this Agreement, and for other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the Company and the Purchasers agree as follows:

1.     Definitions . Capitalized terms used and not otherwise defined herein that are defined in the Subscription Agreement shall have the meanings given such terms in the Subscription Agreement. As used in this Agreement, the following terms shall have the respective meanings set forth in this Section  1 .

“ Affiliate ” means any Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common control with a Person, as such terms are used in and construed under Rule 144.

“ Business Day ” means any day except Saturday, Sunday and any day that shall be a federal legal holiday or a day on which banking institutions in the State of New York are authorized or required by law or other governmental action to close.

“ Common Stock ” means the Company’s common stock, $0.01 par value per share.

“ Effective Date ” means the date that the Registration Statement filed pursuant to Section  2(a)  is first declared effective by the Commission.

“ Effectiveness Date ” means: (a) with respect to the initial Registration Statement required to be filed to cover the resale by the Holders of the Registrable Securities, the earlier of: (i) the 90 ^th day following the final Closing Date if the Commission does not review the Registration Statement or (ii) 120 days following the final Closing Date if the Commission reviews the Registration Statement, and (b) with respect to any additional Registration Statements that may be required pursuant to Sections 2(a)  and (b)  hereof, the earlier of: (i) the 90 ^th day following the date on which the Company first knows, or reasonably should have known, that such additional Registration Statement is required under such Sections or (ii) the fifth trading day following the date on which the Company is notified by the Commission that such additional Registration Statement will not be reviewed or is no longer subject to further review and comments. “ Effectiveness Date ” shall also have the meaning specified in Section  2(b) .

“ Effectiveness Period ” shall have the meaning set forth in Section  2(a) .

“ Exchange Act ” means the Securities Exchange Act of 1934.

“ Filing Date ” means: (a) with respect to the initial Registration Statement required to be filed to cover the resale by the Holders of the Registrable Securities, the 60 ^th day following the final Closing Date, and (b) with respect to any additional Registration Statements that may be required pursuant to Sections 2(a)  and (b)  hereof, the 60 ^th day following the date on which the Company first knows, or reasonably should have known, that such additional Registration Statement is required under such Sections.

“ Holder ” or “ Holders ” means the holder or holders, as the case may be, from time to time of Registrable Securities.

“ Indemnified Party ” shall have the meaning set forth in Section  5(c) .

“ Indemnifying Party ” shall have the meaning set forth in Section  5(c) .

“ Losses ” shall have the meaning set forth in Section  5(a) .

“ Person ” means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind.

“ Proceeding ” means an action, claim, suit, investigation or proceeding (including, without limitation, an investigation or partial proceeding, such as a deposition), whether commenced or threatened.

“ Prospectus ” means the prospectus included in a Registration Statement (including, without limitation, a prospectus that includes any information previously omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430A promulgated under the Securities Act), as amended or supplemented by any prospectus supplement, with respect to the terms of the offering of any portion of the Registrable Securities covered by a Registration Statement, and all other amendments and supplements to the Prospectus, including post-effective amendments, and all material incorporated by reference or deemed to be incorporated by reference in such Prospectus.

“ Registrable Securities ” means the shares of Common Stock included in a Unit and the shares of Common Stock that may be issued upon the exercise of the Warrants included in a Unit together with any securities issued or issuable upon any stock split, dividend or other distribution, recapitalization or similar event, or any Note conversion rate or Warrant exercise price adjustment with respect thereto.

“ Registration Statement ” means each of the following: (i) an initial registration statement which is required to register the resale of the Registrable Securities, and (ii) each additional registration statement, if any, contemplated by Sections 2(a)  and (b) , and including, in each case, the Prospectus, amendments and supplements to each such registration statement or Prospectus, including pre- and post-effective amendments, all exhibits thereto, and all material incorporated by reference or deemed to be incorporated by reference in such registration statement.

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“ Rule  144 ” means Rule 144 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“ Rule  415 ” means Rule 415 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“ Rule  424 ” means Rule 424 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“ Securities Act ” means the Securities Act of 1933.

“ Selling Stockholders ” shall have meaning defined in Section  3(b)(iii) .

“ Transfer Agent ” means the transfer agent for the Common Stock.

“ Transaction Documents ” means this Agreement, the Subscription Agreement, the Warrants, and any other documents or agreements executed in connection with the transactions contemplated hereunder and in the Subscription Agreement.

“ Unit ” means a unit consisting of 250,000 shares of Common Stock and the A Warrants and the B Warrants.

“ Warrants ” means the A Warrants and the B Warrants each to acquire an aggregate of 125,000 shares of Common Stock at an exercise price of $0.40 per share.

2.     Registration .

(a)     Initial Registration Statements . On or prior to each Filing Date, the Company shall prepare and file with the Commission a Registration Statement covering the resale of all Registrable Securities not already covered by an existing and effective Registration Statement for an offering to be made on a continuous basis pursuant to Rule 415. The Registration Statement shall be on Form S-1, or another appropriate form for such purpose, and shall contain (except if otherwise required pursuant to written comments received from the Commission upon a review of such Registration Statement) the “Plan of Distribution” attached hereto as Annex  A . The Company shall cause the Registration Statement to be declared effective under the Securities Act as soon as possible but, in any event, no later than the Effectiveness Date, and shall use its reasonable best efforts to keep the Registration Statement continuously effective under the Securities Act until the date that is two years after the date that the Registration Statement is declared effective by the Commission or such earlier date when all Registrable Securities covered by the Registration Statement have been sold or may be sold pursuant to Rule 144(b)(i) as determined by the counsel to the Company pursuant to a written opinion letter to such effect, addressed and acceptable to the Transfer Agent and the affected Holders (the “ Effectiveness Period ”). It is agreed and understood that the Company shall, from time to time, be obligated to file an additional Registration Statement to cover any Registrable Securities that are not registered for resale pursuant to a pre-existing Registration Statement.

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(b)     Additional Registration Statements . If for any reason the Commission does not permit all of the Registrable Securities to be included in the Registration Statement filed pursuant to Section  2(a) , then the Company shall prepare and file as soon as possible after the date on which the Commission shall indicate as being the first date or time that such filing may be made, but in any event by the 60 ^th day following such date, an additional Registration Statement covering the resale of all Registrable Securities not already covered by an existing and effective Registration Statement for an offering to be made on a continuous basis pursuant to Rule 415, on Form S-1 or another appropriate form for such purpose. Each such Registration Statement shall contain (except if otherwise required pursuant to written comments received from the Commission upon a review of such Registration Statement) the “Plan of Distribution” attached hereto as Annex  A . The Company shall cause each such Registration Statement to be declared effective under the Securities Act as soon as possible (the “ Effectiveness Date ”) and shall use its reasonable best efforts to keep such Registration Statement continuously effective under the Securities Act during the entire Effectiveness Period.

(c)    I ssuance of Legal Opinion .

(i)    Within three business days after the Effectiveness Date of a Registration Statement, the Company shall cause its counsel to issue a blanket opinion in the form attached hereto as Exhibit A (the “ Form Opinion ”), to the Transfer Agent stating that the Shares, as defined therein, are subject to an effective registration statement and can be reissued free of restrictive legend upon notice of a sale by the Purchaser and confirmation by the Purchaser that it has complied with the prospectus delivery requirements, provided that the Company has not advised the Transfer Agent in writing that the opinion has been withdrawn. Copies of the blanket opinion required by this Section  2(c)  shall be delivered to the Purchasers within the time period set forth above.

(ii)    In connection with Section 2(c)(i), the Company shall obtain confirmation from any new Transfer Agent, as may be engaged by the Company from time to time, that the Form Opinion shall be sufficient to cause the removal of restrictive legends from the Shares (as defined in the Form Opinion) and the Company shall provide confirmation of the same to the Purchasers.

3.     Registration Procedures . In connection with the Company’s registration obligations hereunder, the Company shall:

(a)    Not less than four trading days prior to the filing of a Registration Statement or any related Prospectus or any amendment or supplement thereto, furnish to the Holders copies of all such documents proposed to be filed, which documents (other than those incorporated by reference) will be subject to review by such Holders. The Company shall not file a Registration Statement or any such Prospectus or any amendments or supplements thereto to which the Holders of a majority of the Registrable Securities shall, in writing, reasonably object in good faith.

(b)    (i) Prepare and file with the Commission such amendments, including post-effective amendments, to each Registration Statement and the Prospectus used in connection therewith as may be necessary to keep such Registration Statement continuously effective as to

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the applicable Registrable Securities for its Effectiveness Period and prepare and file with the Commission such additional Registration Statements in order to register for resale under the Securities Act all of the Registrable Securities; (ii) cause the related Prospectus to be amended or supplemented by any required Prospectus supplement, and as so supplemented or amended to be filed pursuant to Rule 424; (iii) respond as promptly as reasonably possible, and in any event within ten trading days, to any comments received from the Commission with respect to each Registration Statement or any amendment thereto and, as promptly as reasonably possible, provide the Holders true and complete copies of all correspondence from and to the Commission relating to such Registration Statement that pertains to the Holders as selling stockholders (the “ Selling Stockholders ”) but not any comments that would result in the disclosure to the Holders of material and non-public information concerning the Company; and (iv) comply in all material respects with the provisions of the Securities Act and the Exchange Act with respect to the Registration Statements and the disposition of all Registrable Securities covered by each Registration Statement.

(c)    Notify the Holders as promptly as reasonably possible (and, in the case of (i)(A) below, not less than three trading days prior to such filing) and (if requested by any such Holder) confirm such notice in writing no later than one trading day following the day (i)(A) when a Prospectus or any Prospectus supplement or post-effective amendment to a Registration Statement is proposed to be filed; (B) when the Commission notifies the Company whether there will be a “review” of such Registration Statement and whenever the Commission comments in writing on such Registration Statement (the Company shall provide true and complete copies thereof and all written responses thereto to each of the Holders that pertain to such Holder as a Selling Stockholder or to the Plan of Distribution, but not information which the Company believes would constitute material and non-public information); and (C) with respect to each Registration Statement or any post-effective amendment, when the same has become effective; (ii) of any request by the Commission or any other federal or state governmental authority for amendments or supplements to a Registration Statement or Prospectus or for additional information that pertains to the Holders as Selling Stockholders or the Plan of Distribution; (iii) of the issuance by the Commission of any stop order suspending the effectiveness of a Registration Statement covering any or all of the Registrable Securities or the initiation of any Proceedings for that purpose; (iv) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from qualification of any of the Registrable Securities for sale in any jurisdiction, or the initiation or threatening of any Proceeding for such purpose; and (v) of the occurrence of any event or condition that makes the financial statements included in a Registration Statement ineligible for inclusion therein or any statement made in such Registration Statement or Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue in any material respect or that requires any revisions to such Registration Statement, Prospectus or other documents so that, in the case of such Registration Statement or the Prospectus, as the case may be, it will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading.

(d)    Use its reasonable best efforts to avoid the issuance of, or, if issued, obtain the withdrawal of (i) any order suspending the effectiveness of a Registration Statement, or (ii) any suspension of the qualification (or exemption from qualification) of any of the Registrable Securities for sale in any jurisdiction, at the earliest practicable moment.

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(e)    Furnish to each Holder, without charge, at least one conformed copy of each Registration Statement and each amendment thereto and all exhibits to the extent requested by such Holder (including those previously furnished or incorporated by reference) promptly after the filing of such documents with the Commission; provided , however , that the Company shall have no obligation to provide any document pursuant to this clause that is available on the EDGAR system.

(f)    Promptly deliver to each Holder, without charge, as many copies of each Prospectus or Prospectuses (including each form of prospectus) and each amendment or supplement thereto as such Holder may reasonably request. The Company hereby consents to the use of such Prospectus and each amendment or supplement thereto by each of the selling Holders in connection with the offering and sale of the Registrable Securities covered by such Prospectus and any amendment or supplement thereto.

(g)    Prior to any public offering of Registrable Securities, use its reasonable best efforts to register or qualify or cooperate with the selling Holders in connection with the registration or qualification (or exemption from such registration or qualification) of such Registrable Securities for offer and sale under the securities or Blue Sky laws of those jurisdictions within the United States set forth on Schedule 3(g) hereto to keep each such registration or qualification (or exemption therefrom) effective during the Effectiveness Period and to do any and all other acts or things necessary or advisable to enable the disposition in such jurisdictions of the Registrable Securities covered by the Registration Statements; provided , however , that the Company shall not be required to qualify generally to do business in any jurisdiction where it is not then so qualified or subject the Company to any material tax in any such jurisdiction where it is not then so subject or to take such actions in states that require merit review.

(h)    Cooperate with the Holders to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be delivered to a transferee pursuant to the Registration Statements, which certificates shall be free, to the extent permitted by the Subscription Agreement and applicable law, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and registered in such names as any such Holders may request. The Company shall cause the Transfer Agent to transmit the Registrable Securities to the Holder by crediting the account of the Holder’s prime broker with the Depository Trust Company through its Deposit Withdrawal Agent Commission system if the Company is then a participant in such system.

(i)    Upon the occurrence of any event contemplated by Section  3(c)(v) , as promptly as reasonably possible, prepare a supplement or amendment, including a post-effective amendment, to the affected Registration Statements or a supplement to the related Prospectus or any document incorporated or deemed to be incorporated therein by reference, and file any other required document so that, as thereafter delivered, no Registration Statement nor any Prospectus will contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading.

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The Company may require each selling Holder to furnish to the Company a certified statement as to the number of shares of Common Stock beneficially owned by such Holder and any Affiliate thereof.

4.     Registration Expenses . All fees and expenses incident to the Company’s performance of its obligation under this Agreement (excluding any underwriting discounts and selling commissions and all legal fees and expenses of legal counsel for any Holder) shall be borne by the Company whether or not any Registrable Securities are sold pursuant to a Registration Statement. The fees and expenses referred to in the foregoing sentence shall include, without limitation, (i) all registration and filing fees (including, without limitation, fees and expenses (A) with respect to filings required to be made with the trading market on which the Common Stock is then listed for trading, if any, and (B) in compliance with applicable state securities or Blue Sky laws), (ii) printing expenses (including, without limitation, expenses of printing certificates for Registrable Securities and of printing prospectuses if the printing of prospectuses is reasonably requested by the holders of a majority of the Registrable Securities included in the Registration Statement), (iii) messenger, telephone and delivery expenses, (iv) fees and disbursements of counsel for the Company, (v) Securities Act liability insurance, if the Company so desires such insurance, and (vi) fees and expenses of all other Persons retained by the Company in connection with the consummation of the transactions contemplated by this Agreement. In addition, the Company shall be responsible for all of its internal expenses incurred in connection with the consummation of the transactions contemplated by this Agreement (including, without limitation, all salaries and expenses of its officers and employees performing legal or accounting duties), the expense of any annual audit and the fees and expenses incurred in connection with the listing of the Registrable Securities on any securities exchange as required hereunder.

5.     Indemnification .

(a)     Indemnification by the Company . The Company shall, notwithstanding any termination of this Agreement, indemnify and hold harmless each Holder, the officers, directors, agents, attorneys, investment advisors, partners, members, shareholders and employees of each of them, each Person who controls any such Holder (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act) and the officers, directors, agents, attorneys and employees of each such controlling Person, to the fullest extent permitted by applicable law, from and against any and all losses, claims, damages, liabilities, costs (including, without limitation, reasonable costs of preparation and reasonable attorneys’ fees) and expenses (collectively, “ Losses ”), as incurred, arising out of or relating to any untrue or alleged untrue statement of a material fact contained in any Registration Statement, any Prospectus or any form of prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex  A hereto for this purpose) or in any preliminary prospectus, or arising out of or relating to any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus or form of prospectus or supplement thereto, in light of the circumstances under which they were made) not misleading, except to the extent, but only to the extent, that (1) such untrue statements or omissions are based

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solely upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement, such Prospectus or such form of Prospectus or in any amendment or supplement thereto (it being understood that each Holder has approved Annex  A hereto for this purpose) or (2) in the case of an occurrence of an event of the type specified in Section  3(c)(ii)-(v) , the use by such Holder of an outdated or defective Prospectus after the Company has notified such Holder in writing that the Prospectus is outdated or defective and prior to the receipt by such Holder of an Advice, as defined in Section  6(c)  below, or an amended or supplemented Prospectus, but only if and to the extent that following the receipt of the Advice or the amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected. The Company shall notify the Holders promptly of the institution, threat or assertion of any Proceeding of which the Company is aware in connection with the transactions contemplated by this Agreement.

(b)     Indemnification by Holders . Each Holder shall, notwithstanding any termination of this Agreement, severally and not jointly, indemnify and hold harmless the Company, its directors, officers, agents, attorneys and employees, each Person who controls the Company (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers, agents, attorneys or employees of such controlling Persons, to the fullest extent permitted by applicable law, from and against all Losses, as incurred, arising solely out of or based solely upon: (x) such Holder’s failure to comply with the prospectus delivery requirements of the Securities Act or (y) any untrue statement of a material fact contained in any Registration Statement, any Prospectus, or any form of prospectus, or in any amendment or supplement thereto, or arising solely out of or based solely upon any omission of a material fact required to be stated therein or necessary to make the statements therein not misleading to the extent, but only to the extent that, (1) such untrue statements or omissions are based solely upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement (it being understood that each Holder has approved Annex  A hereto for this purpose), such Prospectus or such form of Prospectus or in any amendment or supplement thereto or (2) in the case of an occurrence of an event of the type specified in Section  3(c)(ii)-(v) , the use by such Holder of an outdated or defective Prospectus after the Company has notified such Holder in writing that the Prospectus is outdated or defective and prior to the receipt by such Holder of an Advice or an amended or supplemented Prospectus, but only if and to the extent that following the receipt of the Advice or the amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected. In no event shall the liability of any selling Holder hereunder be greater in amount than the dollar amount of the net proceeds received by such Holder upon the sale of the Registrable Securities giving rise to such indemnification obligation.

(c)     Conduct of Indemnification Proceedings . If any Proceeding shall be brought or asserted against any Person entitled to indemnity hereunder (an “ Indemnified Party ”), such Indemnified Party shall promptly notify the Person from whom indemnity is sought (the

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“ Indemnifying Party ”) in writing, and the Indemnifying Party shall assume the defense thereof, including the employment of counsel reasonably satisfactory to the Indemnified Party and the payment of all fees and expenses incurred in connection with defense thereof; provided, however , that the failure of any Indemnified Party to give such notice shall not relieve the Indemnifying Party of its obligations or liabilities pursuant to this Agreement, except (and only) to the extent that it shall be finally determined by a court of competent jurisdiction (which determination is not subject to appeal or further review) that such failure shall have proximately and materially adversely prejudiced the Indemnifying Party.

An Indemnified Party shall have the right to employ separate counsel in any such Proceeding and to participate in the defense thereof, but the fees and expenses of such counsel shall be at the expense of such Indemnified Party or Parties unless: (1) the Indemnifying Party has agreed in writing to pay such fees and expenses; (2) the Indemnifying Party shall have failed promptly to assume the defense of such Proceeding and to employ counsel reasonably satisfactory to such Indemnified Party in any such Proceeding; or (3) the named parties to any such Proceeding (including any impleaded parties) include both such Indemnified Party and the Indemnifying Party, and such Indemnified Party shall have been advised by counsel that a conflict of interest is likely to exist if the same counsel were to represent such Indemnified Party and the Indemnifying Party (in which case, if such Indemnified Party notifies the Indemnifying Party in writing that it elects to employ separate counsel at the expense of the Indemnifying Party, the Indemnifying Party shall not have the right to assume the defense thereof and such counsel shall be at the expense of the Indemnifying Party); provided, however, that the Indemnifying Party shall not be liable for the fees and expenses of more than one separate firm of attorneys at any time for all Indemnified Parties. The Indemnifying Party shall not be liable for any settlement of any such Proceeding effected without its written consent, which consent shall not be unreasonably withheld. No Indemnifying Party shall, without the prior written consent of the Indemnified Party, effect any settlement of any pending Proceeding in respect of which any Indemnified Party is a party, unless such settlement includes an unconditional release of such Indemnified Party from all liability on claims that are the subject matter of such Proceeding.

All fees and expenses of the Indemnified Party (including reasonable fees and expenses to the extent incurred in connection with investigating or preparing to defend such Proceeding in a manner not inconsistent with this Section) shall be paid to the Indemnified Party, as incurred, within ten trading days of written notice thereof to the Indemnifying Party (regardless of whether it is ultimately determined that an Indemnified Party is not entitled to indemnification hereunder; provided, however , that the Indemnifying Party may require such Indemnified Party to undertake to reimburse all such fees and expenses to the extent it is finally judicially determined that such Indemnified Party is not entitled to indemnification hereunder).

(d)     Contribution . If a claim for indemnification under Section  5(a)  or 5(b)  is unavailable to an Indemnified Party (by reason of public policy or otherwise), then each Indemnifying Party, in lieu of indemnifying such Indemnified Party, shall contribute to the amount paid or payable by such Indemnified Party as a result of such Losses, in such proportion as is appropriate to reflect the relative fault of the Indemnifying Party and Indemnified Party in connection with the actions, statements or omissions that resulted in such Losses as well as any other relevant equitable considerations. The relative fault of such Indemnifying Party and Indemnified Party shall be determined by reference to, among other things, whether any action in

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question, including any untrue or alleged untrue statement of a material fact or omission or alleged omission of a material fact, has been taken or made by, or relates to information supplied by, such Indemnifying Party or Indemnified Party, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such action, statement or omission. The amount paid or payable by a party as a result of any Losses shall be deemed to include, subject to the limitations set forth in Section  5(c) , any reasonable attorneys’ or other reasonable fees or expenses incurred by such party in connection with any Proceeding to the extent such party would have been indemnified for such fees or expenses if the indemnification provided for in this Section was available to such party in accordance with its terms.

The parties hereto agree that it would not be just and equitable if contribution pursuant to this Section  5(d) were determined by pro rata allocation or by any other method of allocation that does not take into account the equitable considerations referred to in the immediately preceding paragraph. Notwithstanding the provisions of this Section  5(d) , no Holder shall be required to contribute, in the aggregate, any amount in excess of the amount by which the proceeds actually received by such Holder from the sale of the Registrable Securities subject to the Proceeding exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission.

The indemnity and contribution agreements contained in this Section are in addition to any liability that the Indemnifying Parties may have to the Indemnified Parties.

6.     Miscellaneous

(a)     Remedies . In the event of a breach by the Company or by a Holder, of any of their obligations under this Agreement, each Holder or the Company, as the case may be, in addition to being entitled to exercise all rights granted by law and under this Agreement, including recovery of damages, will be entitled to specific performance of its rights under this Agreement. The Company and each Holder agree that monetary damages would not provide adequate compensation for any losses incurred by reason of a breach by it of any of the provisions of this Agreement and hereby further agrees that, in the event of any action for specific performance in respect of such breach, it shall waive the defense that a remedy at law would be adequate.

(b)     Compliance . Each Holder covenants and agrees that it will comply with the prospectus delivery requirements of the Securities Act as applicable to it in connection with sales of Registrable Securities pursuant to the Registration Statement.

(c)     Discontinued Disposition . Each Holder agrees by its acquisition of such Registrable Securities that, upon receipt of a notice from the Company of the occurrence of any event of the kind described in Section  3(c) , such Holder will forthwith discontinue disposition of such Registrable Securities under the Registration Statement until such Holder’s receipt of the copies of the supplemented Prospectus and/or amended Registration Statement or until it is advised in writing (the “ Advice ”) by the Company that the use of the applicable Prospectus may be resumed, and, in either case, has received copies of any additional or supplemental filings that are incorporated or deemed to be incorporated by reference in such Prospectus or Registration Statement. The Company may provide appropriate stop orders to enforce the provisions of this paragraph.

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(d)     Amendments and Waivers . No provision of this Agreement may be waived or amended except in a written instrument signed by the Company and the Holder or Holders (as applicable) of no less than a majority of the then outstanding Registrable Securities. No waiver of any default with respect to any provision, condition or requirement of this Agreement shall be deemed to be a continuing waiver in the future or a waiver of any subsequent default or a waiver of any other provision, condition or requirement hereof, nor shall any delay or omission of either party to exercise any right hereunder in any manner impair the exercise of any such right.

(e)     Notices . Any and all notices or other communications or deliveries required or permitted to be provided hereunder shall be in writing and shall be deemed given and effective on the earliest of (i) the date of transmission, if such notice or communication is delivered via electronic transmission at the or email address specified in this Section prior to 5:00 p.m. (California time) on a Business Day, (ii) the Business Day after the date of transmission, if such notice or communication is delivered via electronic transmission at the email address specified in this Agreement later than 5:00 p.m. (California time) on any date and earlier than 11:59 p.m. (California time) on such date, (iii) the Business Day following the date of dispatch, if sent by nationally recognized overnight courier service, or (iv) upon actual receipt by the party to whom such notice is required to be given. The address for such notices and communications shall be as follows:

If to the Company:

Mateon Therapeutics, Inc.

701 Gateway Boulevard

Suite 210

South San Francisco, CA 94080

Telephone:    (650) 635-7000

Attention:            Matt Loar, Chief Financial Officer

If to a Purchaser:         To the address set forth under such Purchaser’s name on the signature pages hereto.

If to any other Person who is then the registered Holder:

To the address of such Holder as it appears in the stock transfer books of the Company or such other address as may be designated in writing hereafter, in the same manner, by such Person.

(f)    S uccessors and Assigns . This Agreement shall inure to the benefit of and be binding upon the successors and permitted assigns of each of the parties and shall inure to the benefit of each Holder. The Company may not assign its rights or obligations hereunder without the prior written consent of each Holder. Holders may assign their respective rights hereunder in the manner and to the Persons as permitted under the Subscription Agreement.

(g)     Execution and Counterparts . This Agreement may be executed in any number of counterparts, each of which when so executed shall be deemed to be an original and, all of which taken together shall constitute one and the same Agreement. In the event that any signature is delivered by facsimile or electronic transmission, such signature shall create a valid binding obligation of the party executing (or on whose behalf such signature is executed) the same with the same force and effect as if such facsimile or electronic signature were the original thereof.

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(h)     Governing Law; Venue . All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by and construed and enforced in accordance with the internal laws of the State of Delaware, without regard to the principles of conflicts of law thereof. Each party agrees that all Proceedings concerning the interpretations, enforcement and defense of the transactions contemplated by this Agreement (whether brought against a party hereto or its respective Affiliates, employees or agents) may be commenced in the state and federal courts sitting in San Mateo County, California. Each party hereto hereby irrevocably waives personal service of process and consents to process being served in any such Proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way the right of a party to bring any action or proceeding against another party or its property in the courts of any other jurisdiction or the right of a party to serve process in any manner permitted by law. Each party hereto hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any Proceeding arising out of or relating to this Agreement or the transactions contemplated hereby. If any party shall commence a Proceeding to enforce any provisions of this Agreement, then the prevailing party in such Proceeding shall be reimbursed by the other party for its attorney’s fees and other costs and expenses incurred with the investigation, preparation and prosecution of such Proceeding.

(i)     Cumulative Remedies . The remedies provided herein are cumulative and not exclusive of any remedies provided by law.

(j)     Severability . If any term, provision, covenant or restriction of this Agreement is held by a court of competent jurisdiction to be invalid, illegal, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions set forth herein shall remain in full force and effect and shall in no way be affected, impaired or invalidated, and the parties hereto shall use their reasonable efforts to find and employ an alternative means to achieve the same or substantially the same result as that contemplated by such term, provision, covenant or restriction. It is hereby stipulated and declared to be the intention of the parties that they would have executed the remaining terms, provisions, covenants and restrictions without including any of such that may be hereafter declared invalid, illegal, void or unenforceable.

(k)     Headings . The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

(l)     Independent Nature of Purchasers’ Obligations and Rights . The obligations of each Purchaser hereunder are several and not joint with the obligations of any other Purchaser hereunder, and no Purchaser shall be responsible in any way for the performance of the obligations of any other Purchaser hereunder. The decision of each Purchaser to purchase Units and/or Underlying Securities pursuant to the Transaction Documents has been made independently of any other Purchaser. Nothing contained herein or in any other agreement or document delivered at any closing, and no action taken by any Purchaser pursuant hereto or

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thereto, shall be deemed to constitute the Purchasers as a partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Purchasers are in any way acting in concert with respect to such obligations or the transactions contemplated by this Agreement. Each Purchaser acknowledges that no other Purchaser has acted as agent for such Purchaser in connection with making its investment hereunder and that no Purchaser will be acting as agent of such Purchaser in connection with monitoring its investment in the Units and/or Underlying Securities or enforcing its rights under the Transaction Documents. Each Purchaser shall be entitled to protect and enforce its rights, including without limitation the rights arising out of this Agreement, and it shall not be necessary for any other Purchaser to be joined as an additional party in any proceeding for such purpose.

(m)     Gender . The use herein of the masculine pronouns or similar terms shall be deemed to include the feminine and neuter genders as well and vice versa and the use of the singular pronouns shall be deemed to include the plural as well and vice versa.

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IN WITNESS WHEREOF, the parties have executed this Registration Rights Agreement as of the date first written above.

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SIGNATURE PAGES OF PURCHASER TO FOLLOW]

IN WITNESS WHEREOF, the parties have executed this Registration Rights Agreement as of the date first written above.

Exhibit 10.3

February 7, 2018

Sent via email to:

Mateon Therapeutics

Attn: Matthew M. Loar, Chief Financial Officer

Dear Matt:

The purpose of this letter agreement (this “Engagement Letter” or the “Agreement”) is to set forth the terms and conditions pursuant to which Divine Capital Markets LLC (“Divine” or the “Placement Agent”), shall serve as the Placement Agent; in that capacity Divine shall introduce Mateon Therapeutics, Inc . (the “Company”) to one or more investors (each an “Introduced Investor”) in connection with the proposed $3 to $4 million offering (the “Placement” or “Offering”) of securities (“Securities”) of the Company on a “best efforts” basis, subject to the terms and conditions of this Agreement.

The terms of an Offering and the Securities issued in such Offering shall be mutually agreed upon by the Company and the purchasers in such Offering (each, a “Purchaser” and collectively, the “Purchasers”) and nothing herein enables Divine to bind the Company or any Purchaser; further, the terms and conditions of an Offering and the Securities issued in such Offering shall be subject to approval by the Company’s Board of Directors. This Agreement and the documents executed and delivered by the Company and the Purchasers in connection with the Placement shall be collectively referred to herein as the “Transaction Documents.” The materials utilized to offer the Securities shall be referred to as the “Offering Materials.” The date of each of the closings of an Offering shall be referred to herein as the “Closing Date.” The Company expressly acknowledges and agrees that the Placement Agent’s obligations hereunder are on a reasonable “best efforts” basis only and that the execution of this Agreement does not constitute a commitment by Divine to purchase or to sell the Securities and does not ensure the successful placement of the Securities or any portion thereof. The identities of the Introduced Investors shall be proprietary information of Divine and shall not be divulged to third parties by the Company, nor used by the Company outside the scope of the Placement Agent’s engagement as described herein, other than as required by applicable law and to register their shares with the SEC; provided, however, that nothing in the preceding sentence shall prohibit the Company from communicating with any Purchaser with respect to their investment in the Company.

The subscription proceeds for any Securities sold in the Offering will be deposited in a non-interest bearing escrow account established by the Company and Divine at U.S. Bank, or another mutually acceptable federally chartered bank, in accordance with the requirements of Rule 15c2-4 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the interpretations relating thereto issued by the Financial Industry Regulatory Authority (“FINRA”). Upon Closing of the Offering, the proceeds will be released upon the joint authorization and direction of the Company and the Placement Agent; notwithstanding the foregoing, Divine will authorize, at the direction of the Company, the release of any and all proceeds attributable to investors who are not

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

Introduced Investors; upon termination of the Offering without any Closings, the escrow agreement governing the account shall provide that the escrow agent shall promptly return such proceeds, without the payment of interest and without deduction, to the subscribers.

SECTION 1.    COMPENSATION AND OTHER FEES.

(A)    Commission. As compensation for Divine’s services hereunder, Divine shall be entitled to a selling commission in cash equal to ten percent (10.0%) of the gross proceeds from the sale of Securities as a part of the Offering to Introduced Investors consummated at each Closing, which commission will be due and payable upon the receipt by the Company of the net proceeds thereof from the escrow described in the preceding paragraph (each an “Escrow Closing”).

(B)    Warrants. As additional compensation for the Services to be provided by Divine in connection with the Offering, at the relevant Escrow Closing the Company shall issue to Divine or its designees warrants (the “Divine Warrants”) to purchase that number of Securities equal to ten percent (10.0%) of the aggregate number of Securities sold to Introduced Investors in the relevant Closing; in determining the number of Securities for purposes of issuing Divine Warrants, “Securities” shall take into consideration securities underlying any convertible Securities issued in the Offering for which the Company receives cash proceeds on the Closing Date. Divine Warrants shall have an exercise price equal to 100% of the price at which Securities are issued to Investors, and an exercise period of five years. The Divine Warrants shall be issued to Divine contemporaneously with an Escrow Closing and shall contain customary terms, including, without limitation, provisions for cashless exercise, anti-dilution protections in the event of stock splits and similar events, and registration rights consistent with the registration rights granted to the investors in the Offering.

(C)    Non-Accountable Expense. Upon each closing, the Company also shall pay to Divine a Non-Accountable expense reimbursement equal to three percent (3.0%) of the aggregate gross proceeds received by the Company from the sale of its securities to Introduced Investors.

(D)    Divine shall take any and all steps necessary to ensure that its compensation to be paid for services hereunder complies with any applicable rules and regulations of FINRA.

SECTION 2.    SERVICES TO BE RENDERED BY DIVINE.

Without limiting the generality of the foregoing, Divine will:

(A)    Introduce the Company to potential investors for the Placement;

(B)    Divine agrees to furnish advice to Company in connection with the identification of individual and institutional sources of financing; arrangement of appropriate introductions to such parties; and marketing of financing proposals. Divine will also assist in preparation of the Transaction Documents and Offering Materials. Divine shall also render such other financial consulting and/or investment banking services as may from time to time be agreed upon by Divine and Company.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

(C)    Divine will update the Company on at least a weekly basis on progress of milestones.

SECTION 3.    COMPANY REPRESENTATIONS AND WARRANTIES.

The Company represents and warrants to, and agrees with, Divine that:

(A)    The Offering Memorandum (and any documents that accompany it) as amended or supplemented will comply in all material respects with the Securities Act of 1933, as amended, and the applicable Rules and Regulations thereunder. The Offering Memorandum (and any documents to accompany it) as amended or supplemented will not contain as of the date thereof any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. Any incorporated documents (the “Incorporated Documents”), when filed with the Securities and Exchange Commission (the “Commission”), conformed when filed in all material respects to the requirements of the Exchange Act and the applicable Rules and Regulations, and none of such documents, when they were or are filed with the Commission, contained any untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein (with respect to Incorporated Documents incorporated by reference in the Offering Memorandum as amended or supplemented, in light of the circumstances under which they were made not misleading); and any further documents subsequently incorporated by reference in the Offering Memorandum, as amended or supplemented, when such documents are filed with the Commission, will conform in all material respects to the requirements of the Exchange Act and the applicable Rules and Regulations, as applicable, and will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in light of the circumstances under which they were made, not misleading.

(B)    In communicating with the Introduced Investors, the Company will not, without the prior consent of the Placement Agent, prepare, use or refer to, any Offering Memorandum or other offering materials.

(C)    The Company will furnish promptly to Divine all information and material concerning the Company and the Offering that Divine reasonably requests in connection with the performance of its obligations hereunder. The Company represents and warrants that all information made available to Divine by the Company will, at all times during the period of the engagement of Divine hereunder, be complete and correct in all material respects and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in light of the circumstances under which such statements are made. The Company further represents and warrants that any financial or other projections or forecasts provided to Divine will have been prepared in good faith and will be based upon assumptions which, in light of the circumstances under which they are made, are reasonable. The Company acknowledges and agrees that in rendering its services hereunder Divine will be using and relying upon, without any independent investigation or verification thereof, all information that is or will be furnished to Divine by or on behalf of the Company and on publicly available information, and Divine will not in any respect be responsible for the accuracy or completeness of any of the

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

foregoing information, and that Divine will not undertake to make an independent appraisal of any of the assets or of the business of the Company. The Company understands that in rendering services hereunder Divine does not provide accounting, legal or tax advice and will rely upon the advice of the Placement Agent’s counsel and advisers.

(D)    At its next Annual Meeting of Stockholders, the Company will seek stockholder approval to increase its pool of authorized shares of common stock. At this Annual Meeting of Stockholders, the Company acknowledges and agrees that it will not seek stockholder approval to enact a reverse split of its common stock, unless the Company receives the express written approval of Divine Capital Markets.

SECTION 4.    REPRESENTATIONS AND WARRANTIES.

Divine shall be entitled to rely upon any and all representations and warranties of the Company included in the purchase agreements entered into by the Company and the Purchasers in connection with the Placement, subject to the qualifications and limitations therein, including, but not limited to, any disclosure set forth on an applicable schedule.

SECTION 5.    ENGAGEMENT TERM & SURVIVAL.

Divine’s engagement under this Agreement shall be exclusive for a period of six months from the date hereof, or the date of the final placement Closing (the “Term”). Notwithstanding anything to the contrary contained herein, the Company’s representations and warranties; the provisions concerning confidentiality, indemnification, contribution, choice of law and venue; and the Company’s obligations to pay fees earned and payable pursuant to Section 1 hereof, will survive any expiration or termination of this Agreement. Divine agrees not to use any confidential information concerning the Company provided to them by the Company for any purposes other than those contemplated under this Agreement.

SECTION 6.    CONFIDENTIALITY.

Each Party agrees that any written or oral information including advice rendered by Divine, given in connection with this engagement is for the confidential use of the receiving party only in its evaluation of the transaction and preparation of the Offering Materials and, except as otherwise required by law, each party will not disclose or otherwise refer to the information given that party by the other party in any manner without prior written consent of the providing party.

SECTION 7.    NO FIDUCIARY RELATIONSHIP.

This Agreement does not create, and shall not be construed as creating rights enforceable by any person or entity that is not a party hereto, except those entitled hereto by virtue of the indemnification provisions hereof. The Company acknowledges and agrees that Divine is not and shall not be construed as a fiduciary of the Company and that Divine shall not have any duties or liabilities to the equity holders or the creditors of the Company or to any other person by virtue of this Agreement or the retention of Divine hereunder, all of which are hereby expressly waived.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

SECTION 8.    CLOSING.

The obligations of Divine and the Purchasers, and the Closing(s) of the sale of the Securities hereunder, are subject to the accuracy, when made and on the respective Closing Date, of the representations and warranties of the Company contained or incorporated herein, to the accuracy of the statements of the Company made in any certificates pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder, and to each of the following additional terms and conditions:

(A)    No stop order relating to the Offering shall have been issued by any federal or state agency.

(B)    Divine shall not have discovered on or prior to the Closing Date that the Offering Memorandum or any amendment or supplement thereto or any Incorporated Documents, contains an untrue statement of a fact which, in the opinion of the Placement Agent, is material or omits to state any fact which, in the opinion of the Placement Agent, is material and is required to be stated therein or is necessary to make the statements therein not misleading.

(C)    All corporate proceedings and other legal matters incident to the authorization, form, execution, delivery and validity of each of this Agreement, the Securities, the Offering Memorandum as amended or supplemented, the Transaction Documents, and all other legal matters relating to this Agreement and the transactions contemplated hereby shall be reasonably satisfactory in all material respects to Divine and its counsel, and the Company shall have furnished to Divine and to its counsel all documents and information that they may reasonably request to enable them to pass upon such matters.

(D)    Divine shall have received from outside counsel to the Company such counsel’s written opinion, addressed to each of Divine and the Purchasers dated as of the Closing Date, in form and substance reasonably satisfactory to the Placement Agent.

(E)    Neither the Company nor any of its Subsidiaries (i) shall have sustained since the date of the latest audited or, in the case if an audit has not been completed, unaudited financial statements included or incorporated by reference in the Offering Memorandum, as amended or supplemented, any loss or interference with its business from fire, explosion, flood, terrorist act or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth in or contemplated by the Offering Memorandum, as amended or supplemented, and (ii) since such date there shall not have been any material change in the capital stock or long-term debt of the Company or any of its Subsidiaries or any change, or any development involving a prospective change, in or affecting the business, general affairs, management, financial position, stockholders’ equity, results of operations or prospects of the Company and its Subsidiaries, other than losses in the Company’s ordinary course of business incurred in connection with the development of investigational drugs for oncology indications, otherwise than as set forth in or contemplated by the Offering Memorandum, as amended or supplemented, the effect of which, in any such case described in clause (i) or (ii), is, in the judgment of the Placement Agent, so material and adverse as to make it impracticable or inadvisable to proceed with the sale or delivery of the Securities on the terms and in the manner contemplated by the Offering Memorandum, as amended or supplemented.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

(F)    Subsequent to the execution and delivery of this Agreement, there shall not have occurred any of the following: (i) trading in securities generally on the New York Stock Exchange, the Nasdaq Global Market or the NYSE American or in the over-the-counter market, or trading in any securities of the Company on any exchange or in the over-the-counter market, shall have been suspended or minimum or maximum prices or maximum ranges for prices shall have been established on any such exchange or such market by the Commission, by such exchange or by any other regulatory body or governmental authority having jurisdiction, (ii) a banking moratorium shall have been declared by federal or state authorities or a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States, (iii) the United States shall have become engaged in hostilities in which it is not currently engaged, the subject of an act of terrorism, there shall have been an escalation in hostilities involving the United States, or there shall have been a declaration of a national emergency or war by the United States, or (iv) there shall have occurred any other calamity or crisis or any change in general economic, political or financial conditions in the United States or elsewhere, if the effect of any such event in clause (iii) or (iv) makes it, in the sole judgment of the Placement Agent, impracticable or inadvisable to proceed with the sale or delivery of the Securities on the terms and in the manner contemplated by Offering Memorandum, as amended or supplemented.

(G)    No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any governmental agency or body which would, as of a Closing Date, prevent the issuance or sale of the Securities or materially and adversely affect the business or operations of the Company; and no injunction, restraining order or order of any other nature by any federal or state court of competent jurisdiction shall have been issued as of a Closing Date which would prevent the issuance or sale of the Securities or materially and adversely affect the business or operations of the Company.

(H)    The Company shall be obligated following Closing to prepare and file with the Commission a Current Report on Form 8-K with respect to the Placement.

(I)    The Company shall have entered into subscription agreements with each of the Purchasers and such agreements shall be in full force and effect and shall contain representations and warranties of the Company as agreed between the Company and the Purchasers.

(J)    Prior to the Closing Date, the Company shall have furnished to Divine such further information, certificates and documents as either of Divine or its counsel shall request.

(K)    The terms of the Offering and of the Securities shall be acceptable to the Placement Agent.

(L)    The Transaction Documents shall be acceptable in form and substance to the Placement Agent.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

(M)    The Company shall have paid or made arrangements for the prompt payment of all Offering out of pocket expenses (not to exceed $25,000), including the Blue Sky fees and expenses relating Blue Sky services to be performed by counsel to the Placement Agent. Out of pocket expenses in excess shall be submitted to the Company in advance for approval, which approval shall not be unreasonably withheld.

All opinion letters, evidence and certificates mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Placement Agent.

SECTION 9.    INDEMNIFICATION.

The parties agree to the terms of Divine’s standard indemnification agreement, which is attached hereto as Appendix A and incorporated herein by reference. The provisions of this Section 9 shall survive any termination of this Agreement.

SECTION 10. ANNOUNCEMENTS.

The Company grants to Divine the right to place customary announcement(s) of the Placement in certain newspapers and to mail announcement(s) to persons and firms selected by Placement Agent subject to the Company’s prior written approval, which shall not be unreasonably withheld, and all costs of such announcement(s) will be borne by Divine.

SECTION 11. GOVERNING LAW.

This Agreement will be governed by, and construed in accordance with, the laws of the State of New York applicable to agreements made and to be performed entirely in such State. This Agreement may not be assigned by either party without the prior written consent of the other party. This Agreement shall be binding upon and inure to the benefit of the parties hereto, and their respective successors and permitted assigns. Any right to trial by jury with respect to any dispute arising under this Agreement or any transaction or conduct in connection herewith is waived. Any dispute arising under this Agreement may be brought into the courts of the State of New York located in New York County or into the Federal Court located in Manhattan, New York, New York and, by execution and delivery of this Agreement, the Company hereby accepts for itself and in respect of its property, generally and unconditionally, the jurisdiction of aforesaid courts. Each party hereto hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by delivering a copy thereof via overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law. If either party shall commence an action or proceeding to enforce any provisions of a Transaction Document, then the prevailing party in such action or proceeding shall be reimbursed by the other party for its attorney’s fees and other costs and expenses incurred with the investigation, preparation and prosecution of such action or proceeding.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

SECTION 12. ENTIRE AGREEMENT/MISC.

This Agreement embodies the entire agreement and understanding between the parties hereto, and supersedes all prior agreements and understandings, relating to the subject matter hereof. If any provision of this Agreement is determined to be invalid or unenforceable in any respect, such determination will not affect such provision in any other respect or any other provision of this Agreement, which will remain in full force and effect. This Agreement may not be amended or otherwise modified or waived except by an instrument in writing signed by each of Divine and the Company. The representations, warranties, agreements and covenants contained herein shall survive the closing of the Placement and delivery and/or exercise of the Securities, as applicable. This Agreement may be executed in two or more counterparts, all of which when taken together shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party, it being understood that both parties need not sign the same counterpart. In the event that any signature is delivered by facsimile transmission or a .pdf format file, such signature shall create a valid and binding obligation of the party executing (or on whose behalf such signature is executed) with the same force and effect as if such facsimile or .pdf signature page were an original thereof.

SECTION 13. NOTICES.

Any and all notices or other communications or deliveries required or permitted to be provided hereunder shall be in writing and shall be deemed given and effective on the earliest of (a) the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number specified on the signature pages attached hereto prior to 6:30 p.m. (New York time) on a business day, (b) the next business day after the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number on the signature pages attached hereto on a day that is not a business day or later than 6:30 p.m. (New York time) on any business day, (c) the business day following the date of mailing, if sent by U.S. nationally recognized overnight courier service, or (d) upon actual receipt by the party to whom such notice is required to be given. The address for such notices and communications shall be as set forth on the signature pages hereto.

Please confirm that the foregoing correctly sets forth our agreement by signing and returning an executed copy of this Agreement to the Placement Agent.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

Signatures continued next page

Address for notice:

Divine Capital Markets LLC

39 Broadway 36 ^th Floor

New York, NY 10003

Accepted and Agreed to as of

The date first written above:

Address for notice:

701 Gateway Blvd., Suite 210

South San Francisco, CA 94080

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

APPENDIX A — INDEMNIFICATION PROVISIONS

(A)    The Company agrees to indemnify and hold harmless Divine and its affiliates and their respective officers, directors, employees, agents, counsel, advisers and consultants, and any persons controlling Divine or any of its affiliates within the meaning of Section 15 of the Securities Act of 1933 or Section 20 of the Securities Exchange Act of 1934 (Divine and each such other person or entity being referred to herein as an “Indemnified Person”), from and against all claims, liabilities, losses or damages (or actions in respect thereof) or other expenses which (A) are related to or arise out of (i) actions taken or omitted to be taken (including any untrue statements made or any statements omitted to be made) by the Company or its respective affiliates or (ii) actions taken or omitted to be taken by an Indemnified Person with the consent or in conformity with the actions or omissions of the Company or their respective affiliates or (iii) any investigation, litigation, or inquiry by a regulatory or self-regulatory agency or authority involving the Company or any transaction arising under any agreements between the Company and Divine or (B) are otherwise related to or arise out of the Placement Agent’s activities on behalf of the Company or its respective affiliates pursuant to this Agreement or (C) in any way involving or alleged to involve the Company, the Offering or the Securities. The Company will not be responsible, however, for any losses, claims, damages, liabilities or expenses pursuant to clause (B) of the preceding sentence which are resulted from such Indemnified Person’s violation of law, gross negligence or willful misconduct. In addition, the Company agrees to advance (and in the absence of advancement required hereunder) to promptly reimburse each Indemnified Person for all out-of-pocket expenses (including fees and expenses of counsel) as they are incurred by such Indemnified Person in connection with investigating, preparing, conducting or defending any such action or claim, whether or not in connection with litigation in which any Indemnified Person is a named party, or in connection with enforcing the rights of such Indemnified Person under this Agreement.

(B)    Promptly after receipt by Divine of notice of any claim or the commencement of any action or proceeding with respect to which Divine is entitled to indemnity hereunder, Divine will notify the Company in writing of such claim or of the commencement of such action or proceeding, and the Company will assume the defense of such action or proceeding and will employ counsel reasonably satisfactory to Divine and will pay the fees and expenses of such counsel. Notwithstanding the preceding sentence, Divine will be entitled to employ counsel separate from counsel for the Company and from any other party in such action if counsel for Divine determines that to do so would be in the best interests of the Placement Agent. In such event, the reasonable fees and disbursements of no more than one such separate counsel will be paid by the Company. The Company will have the exclusive right to settle the claim or proceeding at its sole expense provided (i) such settlement includes an unconditional release of each Indemnified Party from any liabilities arising out of such action and does not include any findings of fact or admissions of culpability as to the Indemnified Party and (ii) the parties agree that the terms of such Settlement shall remain confidential.

(C)    The Company agrees to notify Divine promptly of the assertion against it or any other person of any claim or the commencement of any action or proceeding relating to a transaction contemplated by this engagement letter.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN

(D)    If for any reason the foregoing indemnity is unavailable to Divine or insufficient to hold Divine harmless, then the Company shall contribute to the amount paid or payable by Divine as a result of such tosses, claims, damages or liabilities in such proportion as is appropriate to reflect not only the relative benefits received by the Company on the one hand and the Placement Agent on the other, but also the relative fault of the Company on the one hand and Divine on the other that resulted in such losses, claims, damages or liabilities, as well as any relevant equitable considerations. The amounts paid or payable by a party in respect of losses, claims, damages and liabilities referred to above shall be deemed to include any legal or other fees and expenses incurred in defending any litigation, proceeding or other action or claim. Notwithstanding the provisions hereof, the Placement Agent’s share of the liability hereunder shall not be in excess of the amount of fees actually received, or to be received, by such Placement Agent under this engagement letter (excluding any amounts received as reimbursement of expenses incurred by such Placement Agent).

(E)    These indemnification provisions shall remain in full force and effect whether or not the transaction contemplated by this Agreement is completed and shall survive the termination of this Agreement, and shall be in addition to any liability that the Company might otherwise have to any indemnified party under this engagement letter or otherwise.

DIVINE CAPITAL MARKETS LLC

NEW YORK I CHICAGO

39 Broadway, 36’’’ Floor, New York, NY 10006     |     tel 212 344 5867     |     fax 212 509 5867     |     www.divinecapitaLcom     |     Membel FINRA sine MSFIN