Exhibit 10.23

SECURITIES PURCHASE AGREEMENT

T HIS S ECURITIES P URCHASE A GREEMENT (the “ Agreement ”), dated as of May 29, 2012, by and among A CEL R X P HARMACEUTICALS , I NC . , a Delaware corporation with headquarters located at 575 Chesapeake Drive, Redwood City, CA 94063 (the “ Company ”), and the investors listed on the Schedule of Investors attached hereto as Exhibit A (individually, an “ Investor ” and collectively, the “ Investors ”).

BACKGROUND

A. Each Investor, severally and not jointly, wishes to purchase, and the Company wishes to sell, upon the terms and conditions stated in this Agreement, (i) that aggregate number of shares of the common stock, par value $0.001 per share, of the Company (the “ Common Stock ”), set forth opposite such Investor’s name on Exhibit A hereto under the heading “Common Shares” (which aggregate amount for all Investors together shall be 2,922,337 shares of Common Stock and shall collectively be referred to herein as the “ Common Shares ”) and (ii) warrants, in substantially the form attached hereto as Exhibit F (the “ Warrants ”), to acquire up to that number of additional shares of Common Stock set forth opposite such Investor’s name on Exhibit A hereto under the heading “Warrant Shares” (the shares of Common Stock issuable upon exercise of or otherwise pursuant to the Warrants, collectively, the “ Warrant Shares ”).

B. The Company and each Investor are executing and delivering this Agreement in reliance upon the exemption from registration afforded by Section 4(2) of the Securities Act of 1933, as amended (the “ Securities Act ”), and Rule 506 of Regulation D (“ Regulation D ”) as promulgated by the United States Securities and Exchange Commission (the “ SEC ”) under the Securities Act.

C. The Common Shares, the Warrants and the Warrant Shares issued or issuable pursuant to this Agreement are collectively referred to herein as the “ Securities .”

N OW , T HEREFORE , IN C ONSIDERATION 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 Investors agree as follows:

ARTICLE I

DEFINITIONS

1.1 Definitions . In addition to the terms defined elsewhere in this Agreement, the following terms have the meanings indicated:

“ Additional Filing Date ” means, with respect to any Additional Registration Statement(s) that may be required (a) the first date that such Registrable Securities may then be included in a Registration Statement if such Registration Statement is required because the SEC shall have notified the Company in writing that certain Registrable Securities were not eligible for inclusion on a previously filed Registration Statement, or (b) if such additional Registration Statement is required for a reason other than as described in (a) above, the thirtieth (30th) day following the date on which the Company first knows that such Additional Registration Statement is required.

“ Additional Registration Statement ” has the meaning set forth in Section 6.1(a) .

“ Additional Required Effectiveness Date ” means with respect to any Additional Registration Statement(s), (a) the sixtieth (60th) day following the first date or time that such Registrable Securities may then be included in a Registration Statement if such Registration Statement is required because the SEC shall have notified the Company in writing that certain Registrable Securities were not eligible for inclusion on a previously filed Registration Statement, or (b) if such additional Registration Statement is required for a reason other than as described in (a) above, the ninetieth (90th) day following the date on which the Company first knows that such Additional Registration Statement(s) is required.

“ 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 under the Securities Act.

“ Agent ” has the meaning set forth in Section 3.1(l) .

“ Agreement ” has the meaning set forth in the Preamble.

“ Business Day ” means any day other than Saturday, Sunday or other day on which commercial banks in the City of New York are authorized or required by law to remain closed.

“ Closing ” means the closing of the purchase and sale of the Securities pursuant to Section 2.1 .

“ Closing Date ” means the date and time of the Closing and shall be 11:00 a.m., New York City time, on June 1, 2012 or such later date and time as is mutually agreed to by the Company and each Investor.

“ Closing Price ” means, for any date, the closing price per share of the Common Stock for such date (or, if such date is not a Trading Day, the nearest preceding date that is a Trading Day) on the primary Eligible Market or exchange or quotation system on which the Common Stock is then listed or quoted.

“ Company ” has the meaning set forth in the Preamble.

“ Company Counsel ” means Cooley LLP, counsel to the Company.

“ Company’s Knowledge ” means with respect to any statement made to the knowledge of the Company, that the statement is based upon the actual knowledge of the chief executive officer, the chief financial officer or the chief technology officer (or an officer performing similar functions) of the Company.

“ Common Shares ” has the meaning set forth in the Preamble.

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“ Convertible Securities ” means any stock or securities (other than Options) convertible into or exercisable or exchangeable for Common Stock.

“ Disclosure Materials ” has the meaning set forth in Section 3.1(g) .

“ Effective Date ” means the date that a Registration Statement is first declared effective by the SEC.

“ Effectiveness Period ” has the meaning set forth in Section 6.1(b) .

“ 8-K Filing ” has the meaning set forth in Section 4.5 .

“ Eligible Market ” means any of The New York Stock Exchange, Inc., The NYSE Amex, The NASDAQ Global Select Market, the NASDAQ Global Market, The NASDAQ Capital Market, or the OTC Bulletin Board.

“ Environmental Laws ” has the meaning set forth in Section 3.1(cc) .

“ Event ” has the meaning set forth in Section 6.1(d) .

“ Event Payments ” has the meaning set forth in Section 6.1(d) .

“ Exchange Act ” means the Securities Exchange Act of 1934, as amended.

“ Excluded Events ” has the meaning set forth in Section 6.1(d)(ii) .

“ Excluded Investors ” means Cowen and Company, LLC and its Affiliates, other than Ramius LLC and any investment funds or managed accounts managed or advised by Ramius LLC.

“ Filing Date ” means the Initial Filing Date and the Additional Filing Date, as applicable.

“ GAAP ” has the meaning set forth in Section 3.1(g) .

“ Indemnified Party ” has the meaning set forth in Section 6.4(c) .

“ Indemnifying Party ” has the meaning set forth in Section 6.4(c) .

“ Initial Filing Date ” means 30 calendar days after the Closing Date or, if such date is not a Business Day, the next date that is a Business Day.

“ Initial Registration Statement ” has the meaning set forth in Section 6.1(a) .

“ Initial Required Effectiveness Date ” means the date which is the earliest of (i) if the Registration Statement does not become subject to review by the SEC, (a) sixty (60) days after the Closing Date or (b) five (5) Trading Days after the Company receives notification from the SEC that the Registration Statement will not become subject to review and the Company fails to request to accelerate the effectiveness of the Registration Statement, or (ii) if the Registration Statement becomes subject to review by the SEC, ninety (90) days after the Closing Date, or, if such date is not a Business Day, the next date that is a Business Day.

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“ Lien ” means any lien, charge, claim, security interest, encumbrance, right of first refusal or other restriction.

“ Losses ” means any and all losses, claims, damages, liabilities, settlement costs and expenses, including, without limitation reasonable attorneys’ fees.

“ Material Adverse Effect ” means (i) a material adverse effect on the financial condition, results of operations, assets, business of the Company or (ii) a material and adverse impairment of the Company’s ability to perform its obligations under any of the Transaction Documents; except that any of the following, either alone or in combination, shall not be deemed a Material Adverse Effect: (i) effects caused by changes or circumstances affecting general market conditions in the U.S. economy or which are generally applicable to the industry in which the Company operates, (ii) effects resulting from or relating to the announcement or disclosure of the sale of the Securities or other transactions contemplated by this Agreement, or (iii) effects caused by any event, occurrence or condition resulting from or relating to the taking of any action in accordance with this Agreement.

“ Material Contract ” means any contract of the Company that has been filed or was required to have been filed as an exhibit to the SEC Reports pursuant to Item 601(b)(4) or Item 601(b)(10) of Regulation S-K.

“ Material Permits ” has the meaning set forth in Section 3.1(u) .

“ Options ” means any outstanding rights, warrants or options to subscribe for or purchase Common Stock or Convertible Securities.

“ Person ” means an individual, a limited liability company, a partnership, a joint venture, a corporation, a trust, an unincorporated organization, any other entity and a government or any department or agency thereof.

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

“ Prospectus ” means the prospectus included in the 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 the 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 Common Shares and the Warrant Shares issued or issuable pursuant to the Transaction Documents, without taking into account any limitations on

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exercise of the Warrants, together with any securities issued or issuable upon any stock split, dividend or other distribution, recapitalization or similar event with respect to the foregoing, provided that the Investor has completed and delivered to the Company a Registration Statement Questionnaire; and provided, further, that the Common Shares and the Warrant Shares shall cease to be Registrable Securities upon the earliest to occur of the following: (A) sale pursuant to a Registration Statement or Rule 144 under the Securities Act, or (B) becoming eligible for sale by an Investor pursuant to Rule 144 without the requirement to be in compliance with Rule 144(c)(1).

“ Registration Statement ” means each registration statement required to be filed under Article VI, including the Initial Registration Statement, all Additional Registration Statements, and, in each case, the Prospectus, amendments and supplements to 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.

“ Required Effectiveness Date ” means the Initial Required Effectiveness Date and the Additional Required Effectiveness Date, as applicable.

“ Rule 144 ,” “ Rule 415 ,” and “ Rule 424 ” means Rule 144, Rule 415 and Rule 424, respectively, promulgated by the SEC pursuant to the Securities Act, as such Rules may be amended from time to time, or any similar rule or regulation hereafter adopted by the SEC having substantially the same effect as such Rule.

“ SEC ” has the meaning set forth in the Preamble.

“ Securities ” has the meaning set forth in the Preamble.

“ Securities Act ” has the meaning set forth in the Preamble.

“ SEC Guidance ” means (i) any publicly-available written or oral guidance, comments, requirements or requests of the SEC staff and (ii) the Securities Act.

“ SEC Reports ” has the meaning set forth in Section 3.1(g) .

“ Shares ” means shares of the Company’s Common Stock.

“ Short Sales ” has the meaning set forth in Section 3.2(i) .

“ Subsidiary ” means any Significant Subsidiary (which for purposes of this Agreement has the meaning ascribed to such term in Regulation S-X under the Exchange Act) of the Company.

“ Trading Day ” means (a) any day on which the Common Stock is listed or quoted and traded on its primary Trading Market, or (b) if the Common Stock is not then listed or quoted and traded on its primary Trading Market, then a day on which trading of the Common Stock occurs on an Eligible Market, or (c) if the Common Stock is not listed or quoted as set forth in clauses (a) or (b) hereof, any Business Day.

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“ Trading Market ” means The NASDAQ Global Market or The NASDAQ Capital Market or any other Eligible Market, or any national securities exchange, market or trading or quotation facility on which the Common Stock is then listed or quoted.

“ Transaction Documents ” means this Agreement, the schedules and exhibits attached hereto, the Warrants and the Transfer Agent Instructions.

“ Transfer Agent ” means Computershare, Inc., or any successor transfer agent for the Company.

“ Transfer Agent Instructions ” means, with respect to the Company, the Irrevocable Transfer Agent Instructions, in the form of Exhibit E , executed by the Company and delivered to and acknowledged in writing by the Transfer Agent.

“ Warrants ” has the meaning set forth in the Preamble.

“ Warrant Shares ” has the meaning set forth in the Preamble.

ARTICLE II

PURCHASE AND SALE

2.1 Closing. Subject to the terms and conditions set forth in this Agreement, at the Closing the Company shall issue and sell to each Investor, and each Investor shall, severally and not jointly, purchase from the Company, the number of Common Shares and Warrants exercisable for the number of Warrant Shares set forth opposite such Investor’s name on Exhibit A hereto under the headings “Common Shares” and “Warrant Shares” for the price set forth opposite such Investor’s name on Exhibit A hereto under the heading “Purchase Price”. The date and time of the Closing and shall be 11:00 a.m., New York City time, on the Closing Date. The Closing shall take place at the offices of the Company Counsel.

2.2 Closing Deliveries.

(a) At the Closing, the Company shall deliver or cause to be delivered to each Investor the following:

(i) a Warrant, pursuant to which such Investor shall have the right to acquire such number of Warrant Shares set forth opposite such Investor’s name on Exhibit A hereto under the heading “Warrant Shares”, registered in the name of such Investor (or its designee);

(ii) a legal opinion of Company Counsel, in the form of Exhibit C , executed by such counsel and delivered to the Investors and the Agent; and

(iii) e-mailed copies of the original stock certificates, with the original stock certificates delivered within three (3) Business Days of the Closing.

(b) At the Closing, each Investor shall deliver or cause to be delivered to the Company the purchase price set forth opposite such Investor’s name on Exhibit A hereto under

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the heading “Purchase Price” in United States dollars and in immediately available funds, by wire transfer to an account designated in writing to such Investor by the Company for such purpose.

ARTICLE III

REPRESENTATIONS AND WARRANTIES

3.1 Representations and Warranties of the Company. The Company hereby represents and warrants as of the date hereof (except for the representations and warranties that speak as of a specific date, which shall be made as of such date), to the Investors that, except as set forth in the Schedules delivered herewith or disclosed in the SEC Reports:

(a) Subsidiaries. The Company has no Subsidiaries.

(b) Organization and Qualification. The Company is an entity duly organized, validly existing and in good standing under the laws of the jurisdiction of its incorporation or organization (as applicable), with the requisite legal authority to own and use its properties and assets and to carry on its business as currently conducted. The Company is not in violation of any of the provisions of its respective certificate or articles of incorporation, bylaws or other organizational or charter documents. The Company is duly qualified to do 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, would not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect.

(c) Authorization; Enforcement. The Company has the requisite corporate authority to enter into and to consummate the transactions contemplated by each of the Transaction Documents to which it is a party and otherwise to carry out its obligations hereunder and thereunder. The execution and delivery of each of the Transaction Documents to which it is a party by the Company and the consummation by it of the transactions contemplated hereby and thereby have been duly authorized by all necessary corporate action on the part of the Company and no further consent or action is required by the Company, its Board of Directors or its stockholders. Each of the Transaction Documents to which it is a party has been (or upon delivery will be) duly executed by the Company and is, or 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 may be limited by (i) applicable bankruptcy, insolvency, reorganization or other laws of general application relating to or affecting the enforcement of creditors rights generally, and (ii) the effect of rules of law governing the availability of specific performance and other equitable remedies.

(d) No Conflicts. The execution, delivery and performance of the Transaction Documents to which it is a party by the Company and the consummation by the Company of the transactions contemplated hereby and thereby do not, and will not, (i) conflict with or violate any provision of the Company’s certificate or articles of incorporation, bylaws or other organizational or charter documents, (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

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rights of termination, amendment, acceleration or cancellation (with or without notice, lapse of time or both) of, any Material Contract to which the Company is a party or by which any property or asset of the Company is bound, or affected, except to the extent that such conflict, default, termination, amendment, acceleration or cancellation right would not reasonably be expected to have a Material Adverse Effect, 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 is subject (including, assuming the accuracy of the representations and warranties of the Investors set forth in Section 3.2 hereof, federal and state securities laws and regulations and the rules and regulations of any self-regulatory organization to which the Company or its securities are subject, including all applicable Trading Markets), or by which any property or asset of the Company is bound or affected, except to the extent that such violation would not reasonably be expected to have a Material Adverse Effect.

(e) The Securities. The Securities (including Warrant Shares) are duly authorized and, when issued and paid for in accordance with the Transaction Documents, will be duly and validly issued, fully paid and nonassessable, free and clear of all Liens and will not be subject to preemptive or similar rights of stockholders (other than those imposed by the Investors). The Company has reserved from its duly authorized capital stock the maximum number of shares of Common Stock issuable upon exercise of the Warrants, without taking into account any limitations on exercise of the Warrants. The offer, issuance and sale of the Common Shares, the Warrants and the Warrant Shares to the Investors pursuant to the Agreement, and in the case of the Warrant Shares, pursuant to the Warrants, respectively, are exempt from the registration requirements of the Securities Act.

(f) Capitalization. The aggregate number of shares and type of all authorized, issued and outstanding classes of capital stock, options and other securities of the Company (whether or not presently convertible into or exercisable or exchangeable for shares of capital stock of the Company) is set forth in Schedule 3.1(f) hereto. All outstanding shares of capital stock are duly authorized, validly issued, fully paid and nonassessable and have been issued in compliance in all material respects with all applicable securities laws. Except as disclosed in the SEC Reports, the Company did not have outstanding at May 29, 2012 any other options, warrants, script rights to subscribe to, calls or commitments of any character whatsoever relating to, or securities, rights or obligations convertible into or exercisable or exchangeable for, or entered into any agreement giving any Person any right to subscribe for or acquire, any shares of Common Stock, or securities or rights convertible or exchangeable into shares of Common Stock, that have not been effectively waived. Except for customary adjustments as a result of stock dividends, stock splits, combinations of shares, reorganizations, recapitalizations, reclassifications or other similar events, there are no anti-dilution or price adjustment provisions contained in any security issued by the Company (or in any agreement providing rights to security holders) and the issuance and sale of the Securities will not obligate the Company to issue shares of Common Stock or other securities to any Person (other than the Investors) and will not result in a right of any holder of securities to adjust the exercise, conversion, exchange or reset price under such securities. To the Company’s Knowledge, except as disclosed in the SEC Reports and any Schedules filed with the SEC pursuant to Rule 13d-1 of the Exchange Act by reporting persons, no Person or group of related Persons beneficially owns (as determined pursuant to Rule 13d-3 under the Exchange Act), or has the right to acquire, by agreement with or by obligation binding upon the Company, beneficial ownership of in excess of 5% of the outstanding Common Stock.

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(g) SEC Reports. The Company has filed all reports required to be filed by it under the Exchange Act, including pursuant to Section 13(a) or 15(d) thereof on a timely basis or has received a valid extension of such time of filing and has filed any such SEC Reports prior to the expiration of any such extension and has filed all reports required to be filed by it under the Exchange Act, including pursuant to Section 13(a) or 15(d) thereof, for the 12 months preceding the date hereof. Such reports required to be filed by the Company under the Exchange Act, including pursuant to Section 13(a) or 15(d) thereof, together with any materials filed or furnished by the Company under the Exchange Act, whether or not any such reports were required being collectively referred to herein as the “ SEC Reports ” and, together with this Agreement and the Schedules to this Agreement, the “ Disclosure Materials ”. As of their respective dates, the SEC Reports filed by the Company complied in all material respects with the requirements of the Securities Act and the Exchange Act and the rules and regulations of the SEC promulgated thereunder, and none of the SEC Reports, when filed by the Company, 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 the light of the circumstances under which they were made, not misleading. The financial statements of the Company included in the SEC Reports comply in all material respects with applicable accounting requirements and the rules and regulations of the SEC with respect thereto as in effect at the time of filing. Such financial statements have been prepared in accordance with United States generally accepted accounting principles applied on a consistent basis during the periods involved (“ GAAP ”), except as may be otherwise specified in such financial statements, the notes thereto and except that unaudited financial statements may not contain all footnotes required by GAAP or may be condensed or summary statements, and fairly present in all material respects the consolidated financial position of the Company as of and for the dates thereof and the results of operations and cash flows for the periods then ended, subject, in the case of unaudited statements, to normal, year-end audit adjustments. All material agreements to which the Company is a party or to which the property or assets of the Company are subject are included as part of or identified in the SEC Reports, to the extent such agreements are required to be included or identified pursuant to the rules and regulations of the SEC. There are no material off-balance sheet arrangements (as defined in Regulation S-K under the Act, Item 303(a)(4)(ii)) or any other relationships with unconsolidated entities or other persons, that may have a material current or, to the Company’s Knowledge, material future effect on the Company’s financial condition, results of operations, liquidity, capital expenditures, capital resources or significant components of revenue or expenses.

(h) Financial Statements. Since the date of the latest audited financial statements included within the SEC Reports, except as disclosed in the SEC Reports, (i) there has been no event, occurrence or development that, individually or in the aggregate, has had or that would result in a Material Adverse Effect, (ii) the Company has not incurred any material liabilities 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 SEC, (iii) the Company has not altered its method of accounting or the changed its auditors, except as disclosed in its SEC Reports, (iv) the Company has not declared or made any

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dividend or distribution of cash or other property to its stockholders, in their capacities as such, or purchased, redeemed or made any agreements to purchase or redeem any shares of its capital stock (except for repurchases by the Company of shares of capital stock held by employees, officers, directors, or consultants pursuant to an option of the Company to repurchase such shares upon the termination of employment or services), and (v) the Company has not issued any equity securities to any officer, director or Affiliate, except pursuant to existing Company stock-based plans. The Company has not taken any steps to seek protection pursuant to any bankruptcy law nor, to the Company’s Knowledge, any of its creditors intend to initiate involuntary bankruptcy proceedings.

(i) Absence of Litigation. Except as disclosed in the SEC Reports, there is no action, suit, claim, or Proceeding, or, to the Company’s Knowledge, inquiry or investigation, before or by any court, public board, government agency, self-regulatory organization or body pending or, to the Company’s Knowledge, threatened in writing against or affecting the Company that, individually or in the aggregate, would reasonably be expected to result in a Material Adverse Effect.

(j) Compliance. The Company (i) is not 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), nor has the Company received written notice of a claim that it is in default under or that it is in violation of, any Material Contract 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, except in each case such violation or default would not reasonably be expected to have or result in a Material Adverse Effect.

(k) Title to Assets. The Company has good and marketable title to all property (whether real or personal) described in the SEC Reports, in each case free and clear of all material liens, claims, security interests, other encumbrances or defects except such as are described in the SEC Reports. The property held under lease by the Company is held by it under valid, subsisting and enforceable leases with only such exceptions with respect to any particular lease as do not interfere in any material respect with the conduct of the business of the Company.

(l) No General Solicitation; Placement Agent’s Fees. Neither the Company nor any Person acting on its or their behalf, has engaged in any form of general solicitation or general advertising (within the meaning of Regulation D) in connection with the offer or sale of the Securities. The Company shall be responsible for the payment of any placement agent’s fees, financial advisory fees, or brokers’ commission (other than for persons engaged by any Investor or its investment advisor) relating to or arising out of the issuance of the Securities pursuant to this Agreement. The Company shall pay, and hold each Investor harmless against, any liability, loss or expense (including, without limitation, reasonable attorney’s fees and out-of-pocket expenses) arising in connection with any such claim for fees arising out of the issuance of the Securities pursuant to this Agreement. The Company acknowledges that it has engaged Cowen and Company, LLC as its lead placement agent (the “ Agent ”) in connection with the sale of the Securities. Other than the Agent and JMP Securities, Inc., the Company has not engaged any placement agent or other agent in connection with the sale of the Securities.

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(m) Private Placement. Assuming the accuracy of the Investors’ representations and warranties set forth in Section 3.2, neither the Company nor any Person acting on the Company’s behalf has, directly or indirectly, at any time within the past six months, made any offer or sale of any security or solicitation of any offer to buy any security under circumstances that would (i) eliminate the availability of the exemption from registration under Regulation D under the Securities Act in connection with the offer and sale by the Company of the Securities as contemplated hereby or (ii) cause the offering of the Securities pursuant to the Transaction Documents to be integrated with prior offerings by the Company for purposes of any applicable law, regulation or stockholder approval provisions, including, without limitation, under the rules and regulations of any Trading Market. The sale and issuance of the Securities hereunder does not contravene the rules and regulation of any applicable Trading Market on which the Common Stock is listed or quoted.

(n) Investment Act. The Company is not required to be registered as, and is not an Affiliate of, an “investment company” within the meaning of the Investment Company Act of 1940, as amended.

(o) Form S-3 Eligibility. The Company is eligible to register the Common Shares and the Warrant Shares for resale by the Investors using Form S-3 promulgated under the Securities Act.

(p) Listing and Maintenance Requirements. The Company has not received notice (written or oral) from any Trading Market on which the Common Stock is or has been listed or quoted to the effect that the Company is not in compliance with the listing or maintenance requirements of such Trading Market. The Company is in compliance with all such listing and maintenance requirements.

(q) Registration Rights. Except as described in the SEC Reports, the Company has not granted or agreed to grant to any Person any rights (including “piggy-back” registration rights) to have any securities of the Company registered with the SEC or any other governmental authority that have not been satisfied or waived.

(r) Application of Takeover Protections. There is no control share acquisition, business combination, poison pill (including any distribution under a rights agreement) or other similar anti-takeover provision under the Company’s charter documents or the laws of its state of incorporation that is or could become applicable to any of the Investors as a result of the Investors and the Company fulfilling their obligations or exercising their rights under the Transaction Documents, including, without limitation, as a result of the Company’s issuance of the Securities and the Investors’ ownership of the Securities.

(s) Acknowledgment Regarding Investors’ Purchase of Securities. Based upon the assumption that the transactions contemplated by this Agreement are consummated in all material respects in conformity with the Transaction Documents, the Company acknowledges and agrees that each of the Investors (other than Excluded Investors) is acting solely in the capacity of an arm’s length purchaser with respect to the Transaction Documents and the transactions contemplated hereby and thereby. The Company further acknowledges that no Investor (other than Excluded Investors) is acting as a financial advisor or fiduciary of the

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Company (or in any similar capacity) with respect to this Agreement and the transactions contemplated hereby and any advice given by any Investor (other than Excluded Investors) or any of their respective representatives or agents in connection with the Transaction Documents and the transactions contemplated hereby and thereby is merely incidental to the Investors’ purchase of the Securities. The Company further represents to each Investor that the Company’s decision to enter into this Agreement has been based solely on the independent evaluation of the transactions contemplated hereby by the Company and its representatives.

(t) Intellectual Property. Except as described in the SEC Reports, the Company owns, possesses, or can acquire on reasonable terms, all Intellectual Property necessary for the conduct of the Company’s business as now conducted or as described in the SEC Reports to be conducted, except as such failure to own, possess, or acquire such rights would not result in a Material Adverse Effect. Furthermore, (A) to the Company’s Knowledge, there is no infringement, misappropriation or violation by third parties of any such Intellectual Property, except as such infringement, misappropriation or violation would not result in a Material Adverse Effect; (B) there is no pending or, to the Company’s Knowledge, threatened, action, suit, proceeding or claim by others challenging the Company’s rights in or to any such Intellectual Property; (C) the Intellectual Property owned by the Company, and to the Company’s Knowledge, the Intellectual Property licensed to the Company, has not been adjudged invalid or unenforceable, in whole or in part, and there is no pending or threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property; (D) there is no pending or, to the Company’s Knowledge, threatened action, suit, proceeding or claim by others that the Company infringes, misappropriates or otherwise violates any Intellectual Property or other proprietary rights of others, the Company has not received any written notice of such claim; and (E) to the Company’s Knowledge, no employee of the Company is in or has ever been in violation of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or actions undertaken by the employee while employed with the Company, except as such violation would not result in a Material Adverse Effect. “ Intellectual Property ” shall mean all patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights, licenses, inventions, trade secrets, domain names, technology, know-how and other intellectual property.

(u) Regulatory Permits. The Company possesses all certificates, authorizations and permits issued by the appropriate federal, state, local or foreign regulatory authorities necessary to conduct their respective businesses as presently conducted and described in the SEC Reports (“ Material Permits ”), except where the failure to possess such permits does not, individually or in the aggregate, have or reasonably be expected to result in a Material Adverse Effect, and the Company has not received any written notice of proceedings relating to the revocation or modification of any Material Permit.

(v) Transactions With Affiliates and Employees. Except as set forth or incorporated by reference in the Company’s SEC Reports, none of the officers, directors or employees of the Company is presently a party to any transaction that would be required to be reported on Form 10-K with the Company (other than for ordinary course services as employees,

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officers or 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 such officer, director or employee or, to the Company’s Knowledge, any corporation, partnership, trust or other entity in which any such officer, director, or employee has a substantial interest or is an officer, director, trustee or partner.

(w) Internal Accounting Controls. The Company maintains a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles in the United States and to maintain accountability for assets; (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 existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as disclosed in the SEC Reports, the Company’s internal control over financial reporting is effective and none of the Company, its board of directors and audit committee is aware of any “significant deficiencies” or “material weaknesses” (each as defined by the Public Company Accounting Oversight Board) in its internal control over financial reporting, or any fraud, whether or not material, that involves management or other employees of the Company who have a significant role in the Company’s internal controls; and since the end of the latest audited fiscal year, there has been no change in the Company’s internal control over financial reporting (whether or not remediated) that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting. The Company’s board of directors has, subject to the exceptions, cure periods and the phase-in periods specified in the applicable NASDAQ Marketplace Rules (“ Exchange Rules ”) and the Exchange Act and rules and regulations of the Commission thereunder, validly appointed an audit committee to oversee internal accounting controls whose composition satisfies the applicable requirements of the Exchange Rules and the Company’s board of directors and/or the audit committee has adopted a charter that satisfies the requirements of the Exchange Rules.

(x) Disclosure Controls and Procedures. The Company maintains disclosure controls and procedures (as such term is defined in Rule 13a-15 of the General Rules and Regulations under the Exchange Act) that comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that information required to be disclosed by the Company is accumulated and communicated to the Company’s management, including the Company’s principal executive officer and principal financial officer by others within those entities, such disclosure controls and procedures are effective.

(y) Sarbanes-Oxley Act. The Company is in compliance with any and all applicable requirements of the Sarbanes-Oxley Act of 2002 that are effective as of the date hereof, and any and all applicable rules and regulations promulgated by the SEC thereunder that are effective as of the date hereof.

(z) Foreign Corrupt Practices. Neither the Company nor, to the Company’s Knowledge, any director, officer, agent, employee or other Person acting on behalf of the Company has, in the course of its actions for, or on behalf of, the Company (i) used any

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corporate funds for any unlawful contribution, gift, entertainment or other unlawful expenses relating to political activity; (ii) made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; (iii) violated or is in violation of any provision of the U.S. Foreign Corrupt Practices Act of 1977, as amended; or (iv) made any unlawful bribe, rebate, payoff, influence payment, kickback or other unlawful payment to any foreign or domestic government official or employee.

(aa) Employee Relations. The Company is not a party to any collective bargaining agreement or employs any member of a union. The Company believes that its relations with its employees are as disclosed in the SEC Reports. Except as disclosed in the SEC Reports, during the period covered by the SEC Reports, no executive officer of the Company (as defined in Rule 501(f) of the Securities Act) has notified the Company that such officer intends to leave the Company or otherwise terminate such officer’s employment with the Company. To the Company’s Knowledge, no executive officer of the Company is in violation of any material term of any employment contract, confidentiality, disclosure or proprietary information agreement, non-competition agreement, or any other contract or agreement or any restrictive covenant, and the continued employment of each such executive officer does not subject the Company to any liability with respect to any of the foregoing matters.

(bb) Labor Matters. The Company is in compliance in all material respects with all federal, state, local and foreign laws and regulations respecting labor, employment and employment practices and benefits, terms and conditions of employment and wages and hours, except where failure to be in compliance would not, either individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(cc) Environmental Laws. Except as disclosed in the SEC Reports, the Company is not in violation of any statute, any rule, regulation, decision or order of any Governmental Authority or any court, domestic or foreign, relating to the use, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “ Environmental Laws ”), owns or operates any real property contaminated with any substance that is subject to any environmental laws, is liable for any off-site disposal or contamination pursuant to any environmental laws, or is subject to any claim relating to any environmental laws, which violation, contamination, liability or claim would individually or in the aggregate, have a Material Adverse Effect; and the Company is not aware of any pending investigation which could reasonably be expected to lead to such a claim.

(dd) Tax Status. The Company has filed all federal, state, local and foreign income and franchise tax returns required to be filed, and are not in default in the payment of any taxes which were payable pursuant to said returns or any assessments with respect thereto, other than (A) those currently payable without penalty or interest, or (B) which the Company is contesting in good faith, except where a failure to so pay or file would not have a Material Adverse Effect. There is no pending dispute with any taxing authority relating to any of such returns, and to the Company’s Knowledge, there is no proposed liability for any tax to be imposed upon the properties or assets of the Company for which there is not an adequate reserve reflected in the Company’s financial statements included in the SEC Reports.

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(ee) Manufacturing Practice. To the Company’s Knowledge, and except as would not, individually or in the aggregate, have a Material Adverse Effect, the Company’s manufacturing facilities and operations are in compliance with applicable regulations of the U.S. Food and Drug Administration (the “ FDA ”), including current Good Manufacturing Practices. Except as would not, individually or in the aggregate, have a Material Adverse Effect, the Company is in compliance in all material respects with all applicable rules and regulations of the FDA.

(ff) Shell Company Status. The Company is not, and has never been, an issuer identified in Rule 144(i)(1).

3.2 Representations, Warranties and Covenants of the Investors. Each Investor hereby, as to itself only and for no other Investor, represents, warrants and covenants to the Company and the Agent as follows:

(a) Organization; Authority. Such Investor is an entity duly organized, validly existing and in good standing under the laws of the jurisdiction of its organization with the requisite corporate, partnership or other power and authority to enter into and to consummate the transactions contemplated by the Transaction Documents and otherwise to carry out its obligations hereunder and thereunder. The purchase by such Investor of the Securities hereunder has been duly authorized by all necessary corporate, partnership or other action on the part of such Investor. This Agreement has been duly executed and delivered by such Investor and constitutes the valid and binding obligation of such Investor, enforceable against it in accordance with its terms, except as may be limited by (i) applicable bankruptcy, insolvency, reorganization or other laws of general application relating to or affecting the enforcement of creditors rights generally, and (ii) the effect of rules of law governing the availability of specific performance and other equitable remedies.

(b) No Public Sale or Distribution. Such Investor is (i) acquiring the Common Shares and the Warrants and (ii) upon exercise of the Warrants will acquire the Warrant Shares issuable upon exercise thereof, in the ordinary course of business for its own account and not with a view towards, or for resale in connection with, the public sale or distribution thereof, except pursuant to sales registered under the Securities Act or under an exemption from such registration and in compliance with applicable federal and state securities laws, and such Investor does not have a present arrangement to effect any distribution of the Securities to or through any person or entity; provided, however, that by making the representations herein, such Investor does not agree to hold any of the Securities for any minimum or other specific term and reserves the right to dispose of the Securities at any time in accordance with or pursuant to a registration statement or an exemption under the Securities Act and pursuant to the applicable terms of the Transaction Documents.

(c) Investor Status. At the time such Investor was offered the Securities, it was, and at the date hereof it is, an “accredited investor” as defined in Rule 501(a) under the Securities Act. Such Investor is not a registered broker dealer registered under Section 15(a) of the Exchange Act, or a member of the Financial Industry Regulatory Authority, Inc (“FINRA”) or an entity engaged in the business of being a broker dealer. Except as otherwise disclosed in writing to the Company on Exhibit B-2 (attached hereto) on or prior to the date of this

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Agreement, such Investor is not affiliated with any broker dealer registered under Section 15(a) of the Exchange Act, or a member of FINRA or an entity engaged in the business of being a broker dealer.

(d) Experience of Such Investor. Such Investor, either alone or together with its representatives has such knowledge, sophistication and experience in business and financial matters so as to be capable of evaluating the merits and risks of the prospective investment in the Securities, and has so evaluated the merits and risks of such investment. Such Investor understands that it must bear the economic risk of this investment in the Securities indefinitely, and is able to bear such risk and is able to afford a complete loss of such investment.

(e) Access to Information. Such Investor acknowledges that it has reviewed the Disclosure Materials and has been afforded: (i) the opportunity to ask such questions as it has deemed necessary of, and to receive answers from, the Company and its representatives concerning the terms and conditions of the offering of the Securities and the merits and risks of investing in the Securities; (ii) access to information (other than material non-public information) about the Company and its respective financial condition, results of operations, business, properties, management and prospects sufficient to enable it to evaluate its investment; and (iii) the opportunity to obtain such additional information that the Company possesses or can acquire without unreasonable effort or expense that is necessary to make an informed investment decision with respect to the investment. Neither such inquiries nor any other investigation conducted by or on behalf of such Investor or its representatives or counsel shall modify, amend or affect such Investor’s right to rely on the truth, accuracy and completeness of the Disclosure Materials and the Company’s representations and warranties contained in the Transaction Documents. Such Investor acknowledges that either it has access to the SEC Reports or has received copies of the SEC Reports.

(f) General Solicitation. Such Investor is not purchasing the Securities as a result of any advertisement, article, notice or other communication regarding the Securities published in any newspaper, magazine or similar media, broadcast over television or radio, disseminated over the Internet or presented at any seminar or, to its knowledge, any other general solicitation or general advertisement.

(g) No Governmental Review. Such Investor understands that no United States federal or state agency or any other government or governmental agency has passed on or made any recommendation or endorsement of the Securities or the fairness or suitability of the investment in the Securities nor have such authorities passed upon or endorsed the merits of the offering of the Securities.

(h) No Conflicts. The execution, delivery and performance by such Investor of this Agreement and the consummation by such Investor of the transactions contemplated hereby will not (i) result in a violation of the organizational documents of such Investor or (ii) conflict with, or constitute a default (or an event which 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 of, any agreement, indenture or instrument to which such Investor is a party, or (iii) result in a violation of any law, rule, regulation, order, judgment or decree (including federal and state securities laws) applicable to such Investor, except in the case of clauses (ii) and (iii) above, for such that are not material and do not otherwise affect the ability of such Investor to consummate the transactions contemplated hereby.

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(i) Prohibited Transactions. No Investor, directly or indirectly, and no Person acting on behalf of or pursuant to any understanding with any Investor, has engaged in any purchases or sales of any securities, including any derivatives, of the Company (including, without limitation, any Short Sales involving any of the Company’s securities) (a “ Transaction ”) since the time that such Investor was first contacted by the Company, the Agent or any other Person regarding an investment in the Company. Such Investor covenants that neither it nor any Person acting on its behalf or pursuant to any understanding with such Investor will engage, directly or indirectly, in any Transactions prior to the time the transactions contemplated by this Agreement are publicly disclosed. “ Short Sales ” include, without limitation, all “short sales” as defined in Rule 200 promulgated under Regulation SHO under the Exchange Act and all types of direct and indirect stock pledges, forward sale contracts, options, puts, calls, short sales, swaps, derivatives and similar arrangements (including on a total return basis), and sales and other transactions through non-U.S. broker-dealers or foreign regulated brokers. Other than to other Persons party to this Agreement, such Investor has maintained the confidentiality of all disclosures made to it in connection with this transaction (including the existence and terms of this transaction).

(j) Restricted Securities. The Investors understand that the Securities are characterized as “restricted securities” under the U.S. federal securities laws inasmuch as they are being acquired from the Company in a transaction not involving a public offering and that under such laws and applicable regulations such securities may be resold without registration under the Securities Act only in certain limited circumstances.

(k) Legends. It is understood that, except as provided in Section 4.1(b) of this Agreement, certificates evidencing such Securities shall bear the legend set forth in Section 4.1(b).

(l) No Legal, Tax or Investment Advice. Such Investor understands that nothing in this Agreement or any other materials presented by or on behalf of the Company to the Investor in connection with the purchase of the Securities constitutes legal, tax or investment advice. Such Investor has consulted such legal, tax and investment advisors as it, in its sole discretion, has deemed necessary or appropriate in connection with its purchase of the Securities. Such Investor understands that the Agent has acted solely as the agent of the Company in this placement of the Securities and not to the Investor, and that the Agent makes no representation or warranty with regard to the merits of this transaction or as to the accuracy of any information such Investor may have received in connection therewith. Such Investor acknowledges that he has not relied on any information or advice furnished by or on behalf of the Agent.

(m) Brokers and Finders. No Person will have, as a result of the transactions contemplated by this Agreement, any valid right, interest or claim against or upon the Company or any Investor for any commission, fee or other compensation pursuant to any agreement, arrangement or understanding entered into by or on behalf of the Investor.

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(n) Reliance on Exemptions. Such Investor understands that the Securities being offered and sold to it in reliance on specific exemptions from the registration requirements of United States federal and state securities laws and that the Company is relying in part upon the truth and accuracy of, and such Investor’s compliance with, the representations, warranties, agreements, acknowledgements and understandings of such Investor set forth herein in order to determine the availability of such exemptions and the eligibility of such Investor to acquire the Securities.

(o) Regulation M. Such Investor is aware that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of Common Stock and other activities with respect to the Common Stock by the Investors.

(p) Beneficial Ownership. Assuming the accuracy of the Company’s representation in Section 3.1(f) hereof and assuming that no additional shares of capital stock have been issued by the Company since January 31, 2012, the purchase by such Investor of the Shares and Warrants hereunder will not result in such Investor (individually or together with any other Person with whom such Investor has identified, or will have identified, itself as part of a “group” in a public filing made with the SEC involving the Company’s securities) acquiring, or obtaining the right to acquire, in excess of 19.99% of the outstanding shares of Common Stock or the voting power of the Company on a post-transaction basis that assumes that the Closing shall have occurred. Such Investor does not presently intend to, alone or together with others, make a public filing with the SEC to disclose that it has (or that it together with such other Persons have) acquired, or obtained the right to acquire, as a result of the purchase by such Investor of the Shares and Warrants hereunder (when added to any other securities of the Company that it or they then own or have the right to acquire), in excess of 19.99% of the outstanding shares of Common Stock or the voting power of the Company on a post-transaction basis that assumes that the Closing has occurred.

(q) Residency. Such Investor’s principal executive offices are in the jurisdiction set forth immediately below Investor’s name on the applicable signature page attached hereto.

ARTICLE IV

OTHER AGREEMENTS OF THE PARTIES

4.1 Transfer Restrictions.

(a) The Investors covenant that the Securities will only be disposed of pursuant to an effective registration statement under, and in compliance with the requirements of, the Securities Act or pursuant to an available exemption from the registration requirements of the Securities Act, and in compliance with any applicable state securities laws. In connection with any transfer of Securities other than pursuant to an effective registration statement or Rule 144, the Company may require the transferor to provide to the Company an opinion of counsel selected by the transferor, the form and substance of which opinion shall be reasonably satisfactory to the Company, to the effect that such transfer does not require registration under the Securities Act. Notwithstanding the foregoing, the Company hereby consents to and agrees to register on the books of the Company and with its Transfer Agent, without any such legal

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opinion, except to the extent that the Transfer Agent requests such legal opinion, any transfer of Securities by an Investor to an Affiliate of such Investor, provided that the transferee certifies to the Company that it is an “accredited investor” as defined in Rule 501(a) under the Securities Act and provided that such Affiliate does not request any removal of any existing legends on any certificate evidencing the Securities.

(b) The Investors agree to the imprinting, until no longer required by this Section 4.1(b) , of the following legend on any certificate evidencing any of the Securities:

THESE SECURITIES HAVE NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ SECURITIES ACT ”), OR ANY APPLICABLE STATE SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN COMPLIANCE WITH APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS.

In addition, if any Investor is an Affiliate of the Company, certificates evidencing the Securities issued to such Investor shall bear a customary “affiliates” legend.

The legend set forth above shall be removed and the Company shall issue a certificate without such legend to the holder of the Securities or issue such unlegended Securities to such holder by electronic delivery at the applicable balance account of The Depository Trust Company (“ DTC ”), if, unless otherwise required by state securities laws, (i) such Securities are registered for resale under the Securities Act, (ii) in connection with a sale, assignment or other transfer, such holder provides the Company with an opinion of counsel, the form and substance of which opinion shall be reasonably acceptable to the Company, that the sale, assignment or transfer of the Securities may be made without registration under the applicable requirements of the Securities Act or (iii) such Securities are sold or transferred pursuant to Rule 144 (if the transferor is not an Affiliate of the Company), or such Securities are eligible for sale under Rule 144 without volume restriction.

If the Company shall fail for any reason or for no reason to issue to the holder of the Securities within three (3) Trading Days after the holder has provided reasonable evidence to the Company of the occurrence of any of (i) through (iii) above (the date such evidence is provided to the Company, the “ Removal Date ”), a certificate without such legend to the holder or to issue such Securities to such holder by electronic delivery at the applicable balance account at DTC (as defined below), and if on or after such Trading Day the holder purchases (in an open market transaction or otherwise) Common Shares to deliver in satisfaction of a sale by the holder of such Securities that the holder anticipated receiving without legend from the Company (a “ Buy-In ”), then the Company shall, within three (3) Business Days after the holder’s request and in the holder’s discretion, either (i) pay cash to the holder in an amount equal to the holder’s total

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purchase price (including brokerage commissions, if any) for the Common Shares so purchased (the “ Buy-In Price ”), at which point the Company’s obligation to deliver such unlegended Securities shall terminate, or (ii) promptly honor its obligation to deliver to the holder such unlegended Securities as provided above and pay cash to the holder in an amount equal to the excess (if any) of the Buy-In Price over the product of (A) such number of Common Shares, times (B) the Closing Price on the Removal Date.

(c) The Company will not object to and shall permit (except as prohibited by law) an Investor to pledge or grant a security interest in some or all of the Securities in connection with a bona fide margin agreement or other loan or financing arrangement secured by the Securities, and if required under the terms of such agreement, loan or arrangement, the Company will not object to and shall permit (except as prohibited by law) such Investor to transfer pledged or secured Securities to the pledgee or secured parties. Except as required by law, such a pledge or transfer would not be subject to approval of the Company, no legal opinion of the pledgee, secured party or pledgor shall be required in connection therewith, and no notice shall be required of such pledge. Each Investor acknowledges that the Company shall not be responsible for any pledges relating to, or the grant of any security interest in, any of the Securities or for any agreement, understanding or arrangement between any Investor and its pledgee or secured party. Provided that the Company is in compliance with the terms of this Section 4.1(c) , the Company’s indemnification obligations pursuant to Section 6.4 shall not extend to any Proceeding or Losses arising out of or related to this Section 4.1(c) .

4.2 Furnishing of Information. Until the date that any Investor owning Common Shares, Warrants or Warrant Shares may sell all of them without restriction or limitation under Rule 144 of the Securities Act (or any successor provision) (including, without limitation, the requirement to be in compliance with Rule 144(c)(1)), the Company covenants to use commercially reasonable best efforts to timely file all reports required to be filed by the Company after the date hereof pursuant to the Exchange Act.

4.3 Integration. The Company shall not, and shall use commercially reasonably efforts to ensure that no Affiliate thereof shall, sell, offer for sale or solicit offers to buy or otherwise negotiate in respect of any security (as defined in Section 2 of the Securities Act) that would be integrated with the offer or sale of the Securities in a manner that would require the registration under the Securities Act of the sale of the Securities to the Investors or that would be integrated with the offer or sale of the Securities for purposes of the rules and regulations of any Trading Market such that it would require shareholder approval prior to the closing of such other transaction unless shareholder approval is obtained before the closing of such subsequent transaction.

4.4 Reservation of Securities. The Company shall maintain a reserve from its duly authorized shares of Common Stock for issuance pursuant to the Transaction Documents in such amount as may be required to fulfill its obligations to issue such Shares under the Transaction Documents. In the event that at any time the then authorized shares of Common Stock are insufficient for the Company to satisfy its obligations to issue such Shares under the Transaction Documents, the Company shall promptly take such actions as may be required to increase the number of authorized shares, including obtaining the necessary stockholder approval to amend its certificate of incorporation.

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4.5 Securities Laws Disclosure; Publicity. The Company shall, on or before 8:30 a.m., New York time, on the first Trading Day following execution of this Agreement, issue a press release and file a Current Report on Form 8-K with the SEC (the “ 8-K Filing ”) describing all material terms of the transactions contemplated by the Transaction Documents and including as exhibits to such Current Report on Form 8-K the Transaction Documents and the form of Warrants in the form required by the Exchange Act. Thereafter, the Company shall timely file any filings and notices required by the SEC or applicable law with respect to the transactions contemplated hereby and provide copies thereof to the Investors promptly after filing. Except as herein provided, the Company shall not publicly disclose the name of any Investor, or include the name of any Investor in any press release without the prior written consent of such Investor, unless otherwise required by law. The Company shall not, and shall cause each of its officers, directors, employees and agents not to, provide any Investor with any material nonpublic information regarding the Company from and after the issuance of the above referenced press release without the express written consent of such Investor, unless an Investor have executed a written agreement regarding the confidentiality and use of such information.

4.6 Form D and Blue Sky. The Company agrees to file a Form D with respect to the Securities as required under Regulation D. The Company, on or before the Closing Date, shall take such action as the Company shall reasonably determine is necessary in order to obtain an exemption for or to qualify the Securities for sale to the Investors at the Closing pursuant to this Agreement under applicable securities or “Blue Sky” laws of the states of the United States (or to obtain an exemption from such qualification), and shall provide evidence of any such action so taken to the Investors on or prior to the Closing Date. The Company shall make all filings and reports relating to the offer and sale of the Securities required under applicable securities or “Blue Sky” laws of the states of the United States following the Closing Date.

4.7 Acknowledgement. Each Investor hereunder acknowledges its primary responsibilities under the Securities Act and accordingly will not sell or otherwise transfer the Warrants, Shares, the Warrant Shares or any interest therein without complying with the requirements of the Securities Act. While the Registration Statement remains effective, each Investor hereunder may sell the Shares and Warrant Shares in accordance with the plan of distribution contained in the Registration Statement (if it is selling such securities pursuant to the Registration Statement) and, if it does so, it will comply therewith and with the related prospectus delivery requirements unless an exemption therefrom is available. Each Investor, severally and not jointly with the other Investors, agrees that if it is notified by the Company in writing at any time that the Registration Statement registering the resale of the Shares or the Warrant Shares is not effective or that the prospectus included in such Registration Statement no longer complies with the requirements of Section 10 of the Securities Act, the Investor will refrain from selling such Shares and Warrant Shares until such time as the Investor is notified by the Company that such Registration Statement is effective or such prospectus is compliant with Section 10 of the Exchange Act, unless such Investor is able to, and does, sell such Shares or Warrant Shares pursuant to an available exemption from the registration requirements of Section 5 of the Securities Act.

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ARTICLE V

CONDITIONS

5.1 Conditions Precedent to the Obligations of the Investors. The obligation of each Investor to acquire Securities at the Closing is subject to the satisfaction or waiver by such Investor, at or before the Closing, of each of the following conditions:

(a) Representations and Warranties. The representations and warranties of the Company contained herein shall be true and correct in all material respects (except for those representations and warranties which are qualified by materiality or Material Adverse Effect, which shall be true and correct in all respects) as of the date when made and as of the Closing as though made on and as of such date (except for representations and warranties that speak as of a specific date, which shall be true and correct as of such specified date); and

(b) Performance. The Company and each other Investor shall have performed, satisfied and complied in all material respects with all covenants, agreements and conditions required by the Transaction Documents to be performed, satisfied or complied with by it at or prior to the Closing.

5.2 Conditions Precedent to the Obligations of the Company. The obligation of the Company to sell the Securities at the Closing is subject to the satisfaction or waiver by the Company, at or before the Closing, of each of the following conditions:

(a) Representations and Warranties. The representations and warranties of the Investors contained herein shall be true and correct in all material respects (except for those representations and warranties which are qualified by materiality or Material Adverse Effect, which shall be true and correct in all respects) as of the date when made and as of the Closing Date as though made on and as of such date (except for representations and warranties that speak as of a specific date, which shall be true and correct as of such specified date); and

(b) Performance. The Investors shall have performed, satisfied and complied in all material respects with all covenants, agreements and conditions required by the Transaction Documents to be performed, satisfied or complied with by the Investors at or prior to the Closing.

ARTICLE VI

REGISTRATION RIGHTS

6.1 Registration Statement.

(a) As promptly as possible, and in any event on or prior to the Initial Filing Date, the Company shall prepare and file with the SEC a Registration Statement covering the resale of all Registrable Securities for an offering to be made on a continuous basis pursuant to Rule 415. The Registration Statement shall be on Form S-3 (except if the Company is not then eligible to register for resale the Registrable Securities on Form S-3, in which case such registration shall be on another appropriate form in accordance with the Securities Act and the Exchange Act) and shall contain (except if otherwise requested by the SEC) the “Plan of Distribution” in substantially the form attached hereto as Exhibit D . To the extent the staff of

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the SEC does not permit all of the Registrable Securities to be registered on the initial Registration Statement filed pursuant to this Section 6.1(a) (the “ Initial Registration Statement ”) or for any other reason any Registrable Securities are not then included in a Registration Statement filed under this Agreement, the Company shall file additional Registration Statements (each an “ Additional Registration Statement ”), as promptly as possible, and in any event on or prior to the Additional Filing Date, successively trying to register on each such Additional Registration Statement the maximum number of remaining Registrable Securities until all of the Registrable Securities have been registered with the SEC.

(b) The Company shall use its commercially reasonable best efforts to cause each Registration Statement to be declared effective by the SEC as promptly as possible after the filing thereof, but in any event prior to the applicable Required Effectiveness Date, and shall use commercially reasonable best efforts to keep the Registration Statement continuously effective under the Securities Act until the earlier of (i) the date that all Registrable Securities covered by such Registration Statement have been sold or can be sold publicly without restriction or limitation under Rule 144 (including, without limitation, the requirement to be in compliance with Rule 144(c)(1)) or (ii) the date that is two (2) years following the Closing Date (the “ Effectiveness Period ” ) ; provided that, upon notification by the SEC that a Registration Statement will not be reviewed or is no longer subject to further review and comments, the Company shall request acceleration of such Registration Statement within five (5) Trading Days after receipt of such notice and request that it becomes effective on 4:00 p.m. New York City time on the Effective Dave and file a prospectus supplement for any Registration Statement, whether or not required under Rule 424 (or otherwise), by 9:00 a.m. New York City time the day after the Effective Date.

(c) The Company shall notify the Investors in writing promptly (and in any event within two Trading Days) after receiving notification from the SEC that a Registration Statement has been declared effective.

(d) Should an Event (as defined below) occur, then upon the occurrence of such Event, and on every monthly anniversary thereof until the applicable Event is cured, the Company shall pay to each Investor an amount in cash, as liquidated damages and not as a penalty, equal to one percent (1.0%) of the aggregate Purchase Price of the Registrable Securities then held by the Investor; provided, however, that the total amount of payments pursuant to this Section 6.1(d) shall not exceed, when aggregated with all such payments paid to all Investors, six percent (6%) of the aggregate Purchase Price hereunder. The payments to which an Investor shall be entitled pursuant to this Section 6.1(d) are referred to herein as “ Event Payments .” Any Event Payments payable pursuant to the terms hereof shall apply on a pro rated basis for any portion of a month prior to the cure of an Event. In the event the Company fails to make Event Payments in a timely manner, such Event Payments shall bear interest at the rate of one percent (1.0%) per month (prorated for partial months) until paid in full. All pro rated calculations made pursuant to this paragraph shall be based upon the actual number of days in such pro rated month. The parties agree that the Company will not be liable for liquidated damages under this Section 6.1(d) with respect to (1) any Warrants or Warrant Shares (prior to their issuance), (2) any period after the expiration of the Effectiveness Period, and (3) as to any Registrable Securities which are not permitted by the SEC to be included in a Registration Statement due solely to SEC Guidance from the time that it is determined that such Registrable Securities are

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not permitted to be registered so long as not due to any action taken by the Company to register shares that are not Registrable Securities. In such case, the Event Payments shall be calculated to only apply to the percentage of Registrable Securities which are permitted in accordance with SEC Guidance to be included in such Registration Statement. In the event that the Company registers some but not all of the Registrable Securities, the 1.0% of liquidated damages referred to above for any monthly period shall be reduced to equal the percentage determined by multiplying 1.0% by a fraction, the numerator of which shall be the number of Registrable Securities for which there is not an effective Registration Statement at such time and the denominator of which shall be the number of Registrable Securities at such time. The Required Effectiveness Date for a Registration Statement shall be extended without default or liquidated damages hereunder in the event that the Company’s failure to obtain the effectiveness of the Registration Statement on a timely basis results from (i) the failure of an Investor to timely provide the Company with information requested by the Company and necessary to complete the Registration Statement in accordance with the requirements of the Securities Act (in which the Required Effectiveness Date would be extended with respect to Registrable Securities held by such Investor) or (ii) events or circumstances that are not in any way attributable to the Company.

For such purposes, each of the following shall constitute an “ Event ”:

(i) the Initial Registration Statement or Additional Registration Statement, as applicable, is not filed on or prior to the Initial Filing Date or the Additional Filing Date, as the case may be, or a Registration Statement is not declared effective on or prior to its Required Effectiveness Date; except as provided for in Section 6.1(e) (the “ Excluded Events ”), after the Effective Date of a Registration Statement, (A) an Investor is not permitted to sell Registrable Securities under the Registration Statement (or a subsequent Registration Statement filed in replacement thereof) for any reason (other than the fault of such Investor ) for an aggregate of more than 20 consecutive Trading Days or for more than an aggregate of 40 Trading Days in any 12-month period (which need not be consecutive) or (B) such Registration Statement ceases for any reason (including without limitation by reason of a stop order, or the Company’s failure to update the Registration Statement), but excluding the inability of any Investor to sell the Registrable Securities covered thereby due to market conditions, to remain continuously effective as to all Registrable Securities included in such Registration Statement; or

(ii) at any time during the period commencing from the six (6) month anniversary of the Closing Date and ending at the termination of the Effectiveness Period, if a Registration Statement is not available for the resale of all of the Registrable Securities (other than the fault of such Investor or because all Registrable Securities cannot be registered due to the SEC Guidance) and the Company shall fail for any reason to satisfy the current public information requirement under Rule 144(c).

(e) Notwithstanding anything in this Agreement to the contrary, the Company may, by written notice to the Investors, suspend sales under a Registration Statement after the Effective Date thereof and/or require that the Investors immediately cease the sale of shares of Common Stock pursuant thereto and/or defer the filing of any subsequent Registration Statement if the Company is engaged in a material merger, acquisition or sale or any other pending development that the Company believes may be material, and the Board of Directors determines

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in good faith, by appropriate resolutions, that, as a result of such activity, (A) it would be materially detrimental to the Company (other than as relating solely to the price of the Common Stock) to maintain a Registration Statement at such time or (B) it is in the best interests of the Company to suspend sales under such registration at such time. Upon receipt of such notice, each Investor agrees to immediately discontinue any sales of Registrable Securities pursuant to such registration until such Investor is advised in writing by the Company that the current Prospectus or amended Prospectus, as applicable, may be used. In no event, however, shall this right be exercised to suspend sales beyond the period during which (in the good faith determination of the Company’s Board of Directors) the failure to require such suspension would be materially detrimental to the Company. The Company’s rights under this Section 6.1(e) may be exercised for a period of no more than 20 Trading Days at a time and not more than three times in any twelve-month period, without such suspension being considered as part of an Event Payment determination. Immediately after the end of any suspension period under this Section 6.1(e) , the Company shall take all necessary actions (including filing any required supplemental prospectus) to restore the effectiveness of the applicable Registration Statement and the ability of the Investors to publicly resell their Registrable Securities pursuant to such effective Registration Statement.

(f) The Company shall not, from the date hereof until the Effective Date of the Initial Registration Statement, prepare and file with the SEC a registration statement relating to an offering for its own account or the account of others under the Securities Act of any of its equity securities, other than any registration statement or post-effective amendment to a registration statement (or supplement thereto) relating to the Company’s employee benefit plans registered on Form S-8 or, in connection with an acquisition, on Form S-4. For the avoidance of doubt, the Company shall not be prohibited from preparing and filing with the SEC a registration statement relating to an offering of Common Stock by existing stockholders of the Company under the Securities Act pursuant to the terms of registration rights held by such stockholders.

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

(a) Not less than three Trading Days prior to the filing of a Registration Statement or any related Prospectus or any amendment or supplement thereto, furnish via email to those Investors or their counsels who have supplied the Company with email addresses copies of all such documents proposed to be filed, which documents (other than any document that is incorporated or deemed to be incorporated by reference therein) will be subject to the review of such Investors (it being acknowledged and agreed that if a Investor does not object to or comment on the aforementioned documents within the two Trading Day period, then the Investor shall be deemed to have consented to and approved the use of such documents). The Company shall reflect in each such document when so filed with the SEC such comments regarding the Investors and the plan of distribution as the Investors may reasonably and promptly propose no later than two Trading Days after the Investors have been so furnished with copies of such documents as aforesaid.

(b) (i) Subject to Section 6.1(e) , prepare and file with the SEC such amendments, including post-effective amendments, to each Registration Statement and the Prospectus used in connection therewith as may be necessary to keep the Registration Statement

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continuously effective, as to the applicable Registrable Securities for the Effectiveness Period and prepare and file with the SEC 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; and (iii) comply in all material respects with the provisions of the Securities Act and the Exchange Act with respect to the disposition of all Registrable Securities covered by the Registration Statement during the applicable period in accordance with the intended methods of disposition by the Investors thereof set forth in the Registration Statement as so amended or in such Prospectus as so supplemented provided, however , that, subject to applicable requirements, each Investor shall be responsible for the delivery of the Prospectus to the Persons to whom such Investor sells any of the Shares or the Warrant Shares (including in accordance with Rule 172 under the Securities Act), and each Investor agrees to dispose of Registrable Securities in compliance with the plan of distribution described in the Registration Statement and otherwise in compliance with applicable federal and state securities laws.

(c) Notify the Investors as promptly as reasonably possible, and if requested by the Investors, confirm such notice in writing no later than two Trading Days thereafter, of any of the following events: (i) the SEC notifies the Company whether there will be a “review” of any Registration Statement; (ii) any Registration Statement or any post-effective amendment is declared effective; (iii) the SEC issues any stop order suspending the effectiveness of any Registration Statement or initiates any Proceedings for that purpose; (iv) the Company receives notice of any suspension of the qualification or exemption from qualification of any Registrable Securities for sale in any jurisdiction, or the initiation or threat of any Proceeding for such purpose; (v) the financial statements included in any Registration Statement become ineligible for inclusion therein.

(d) Use commercially reasonable best efforts to avoid the issuance of or, if issued, obtain the withdrawal of (i) any order suspending the effectiveness of any Registration Statement, or (ii) any suspension of the qualification (or exemption from qualification) of any of the Registrable Securities for sale in any jurisdiction, as soon as possible.

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

(f) Promptly deliver to each Investor, without charge, as many copies of the Prospectus or Prospectuses (including each form of prospectus) and each amendment or supplement thereto as such Persons may reasonably request. The Company hereby consents to the use of such Prospectus and each amendment or supplement thereto by each of the selling Investors in connection with the offering and sale of the Registrable Securities covered by such Prospectus and any amendment or supplement thereto to the extent permitted by federal and state securities laws and regulations.

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(g) (i) In the time and manner required by each Trading Market on which the Common Stock is listed, prepare and file with such Trading Market an additional shares listing application covering all of the Registrable Securities; (ii) use commercially reasonable best efforts to take all steps necessary to cause such Registrable Securities to be approved for listing on each such Trading Market as soon as possible thereafter; (iii) if requested by any Investor, provide to such Investor evidence of such approval; and (iv) except as a result of the Excluded Events, during the Effectiveness Period, maintain the listing of such Registrable Securities on each such Trading Market or another Eligible Market.

(h) Prior to any resale of Registrable Securities by an Investor, use commercially reasonable best efforts to register or qualify or cooperate with the selling Investors 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 such jurisdictions within the United States as any Investor requests in writing, to keep each such registration or qualification (or exemption therefrom) effective for so long as required, but not to exceed the duration of the Effectiveness Period, and to do any and all other acts or things reasonably necessary or advisable to enable the disposition in such jurisdictions of the Registrable Securities covered by a Registration Statement; provided , however , that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject.

(i) If requested by the Investors, cooperate with the Investors to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be delivered to a transferee pursuant to a Registration Statement, which certificates shall be free, to the extent permitted by this Agreement and under law, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and registered in such names as any such Investors may reasonably request.

(j) Upon the occurrence of any event described in Section 6.2(c)(vi) , as promptly as reasonably possible, prepare a supplement or amendment, including a post-effective amendment, to the Registration Statement 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, neither the Registration Statement nor such 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 the light of the circumstances under which they were made, not misleading.

(k) It shall be a condition precedent to the obligations of the Company to complete the registration pursuant to this Agreement with respect to the Registrable Securities of any particular Investor (and, to the extent the breach of such obligations would otherwise trigger an Event Payment set forth in Section 6.1(c) , to make such Event Payment) that such Investor furnish to the Company the information specified in Exhibits B-1, B-2 and B-3 hereto and such other information regarding itself, the Registrable Securities and other shares of Common Stock held by it and the intended method of disposition of the Registrable Securities held by it (if different from the Plan of Distribution set forth on Exhibit D hereto) as shall be reasonably

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required to effect the registration of such Registrable Securities and shall complete and execute such documents in connection with such registration as the Company may reasonably request, except in the case of any such information referred to in this paragraph, to the extent the failure to provide such information does not materially affect the Company’s ability to comply with such obligations.

(l) The Company shall comply with all applicable rules and regulations of the SEC under the Securities Act and the Exchange Act, including, without limitation, Rule 172 under the Securities Act, file any final Prospectus, including any supplement or amendment thereof, with the SEC pursuant to Rule 424 under the Securities Act, promptly inform the Investors in writing if, at any time during the Effectiveness Period, the Company does not satisfy the conditions specified in Rule 172 and, as a result thereof, the Investors are required to make available a Prospectus in connection with any disposition of Registrable Securities and take such other actions as may be reasonably necessary to facilitate the registration of the Registrable Securities hereunder.

(m) Not identify any Investor as an underwriter without its prior written consent in any public disclosure or filing with the SEC, the Trading Market or any Eligible Market and any Investor being deemed an underwriter by the SEC shall not relieve the Company of any obligations it has under this Agreement; provided , however , that the foregoing shall not prohibit the Company from including the disclosure found in the “Plan of Distribution” section attached hereto as Exhibit D in the Registration Statement. In addition, and notwithstanding anything to the contrary contained herein, if the Company has received a comment by the SEC requiring an Investor to be named as an underwriter in the Registration Statement (which notwithstanding the reasonable best efforts of the Company is not withdrawn by the SEC) and such Investor elects in writing not to be named as a selling stockholder in the Registration Statement, the Investor shall not be entitled to any Event Payments with respect to such Registration Statement.

6.3 Registration Expenses. The Company shall pay all fees and expenses incident to the performance of or compliance with Article VI of this Agreement by the Company, including without limitation (a) all registration and filing fees and expenses, including without limitation those related to filings with the SEC, any Trading Market, any required filing with FINRA by the Agent, and in connection with applicable state securities or Blue Sky laws, (b) printing expenses (including without limitation expenses of printing certificates for Registrable Securities), (c) messenger, telephone and delivery expenses, (d) fees and disbursements of counsel for the Company, (e) fees and expenses of all other Persons retained by the Company in connection with the consummation of the transactions contemplated by this Agreement, and (f) all listing fees to be paid by the Company to the Trading Market.

6.4 Indemnification.

(a) Indemnification by the Company. The Company shall, notwithstanding any termination of this Agreement, indemnify and hold harmless each Investor, the officers, directors, partners, members, agents and employees of each of them, each Person who controls any such Investor (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act) and the officers, directors, partners, members, agents and employees of each such

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controlling Person, to the fullest extent permitted by applicable law, from and against any and all Losses, as incurred, arising out of or relating to any violation or alleged violation by the Company of the Securities Act, the Exchange Act, any other law, including, without limitation, any state securities law, or any rule or regulation thereunder relating to the offfer or sale of the Registrable Securities, any untrue or alleged untrue statement of a material fact contained in the Registration Statement, any Prospectus or any form of Company prospectus or in any amendment or supplement thereto or in any Company 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 the light of the circumstances under which they were made) not misleading, except to the extent, but only to the extent, that (A) such untrue statements, alleged untrue statements, omissions or alleged omissions are based solely upon information regarding such Investor furnished in writing to the Company by such Investor for use therein, or to the extent that such information relates to such Investor or such Investor’s proposed method of distribution of Registrable Securities and was reviewed and expressly approved by such Investor expressly for use in the Registration Statement, or (B) with respect to any prospectus, if the untrue statement or omission of material fact contained in such prospectus was corrected on a timely basis in the prospectus, as then amended or supplemented, if such corrected prospectus was timely made available by the Company to the Investor, and the Investor seeking indemnity hereunder was advised in writing not to use the incorrect prospectus prior to the use giving rise to Losses.

(b) Indemnification by Investors. Each Investor shall, severally and not jointly, indemnify and hold harmless the Company, its directors, officers, agents 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 or employees of such controlling Persons, to the fullest extent permitted by applicable law, from and against all Losses (as determined by a court of competent jurisdiction in a final judgment not subject to appeal or review) arising solely out of any untrue statement of a material fact contained in the Registration Statement, any Prospectus, or any form of prospectus, or in any amendment or supplement thereto, or arising out of or relating to any 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 the light of the circumstances under which they were made) not misleading, but only to the extent that such untrue statement or omission is contained in any information so furnished by such Investor in writing to the Company specifically for inclusion in such Registration Statement or such Prospectus or to the extent that (i) such untrue statements or omissions are based solely upon information regarding such Investor furnished to the Company by such Investor in writing expressly for use in the Registration Statement or Prospectus, or to the extent that such information relates to such Investor or such Investor’s proposed method of distribution of Registrable Securities and was reviewed and expressly approved by such Investor expressly for use in the Registration Statement (it being understood that the information provided by the Investor to the Company in Exhibits B-1, B-2 and B-3 and the Plan of Distribution set forth on Exhibit D , as the same may be modified by such Investor constitutes information reviewed and expressly approved by such Investor in writing expressly for use in the Registration Statement), such Prospectus or such form of Prospectus or in any amendment or supplement thereto. In no event shall the liability of any selling Investor hereunder be greater in amount than the dollar amount of the net proceeds received by such Investor upon the sale of the Registrable Securities giving rise to such indemnification obligation.

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(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 “ 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, 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: (i) the Indemnifying Party has agreed in writing to pay such fees and expenses; or (ii) the Indemnifying Party shall have failed within 15 days of receiving notification of a Proceeding from an Indemnified Party to assume the defense of such Proceeding and to employ counsel reasonably satisfactory to such Indemnified Party in any such Proceeding; (iii) any counsel engaged by the applicable Indemnifying Party shall fail to timely commence or diligently conduct the defense of any such claim and such failure has materially prejudiced (or, in the reasonable judgment of the Indemnified Party, is in danger of materially prejudicing) the outcome of the applicable claim; or (iv) such Indemnified Party shall have been advised by counsel that a conflict of interest is likely to or may exist between the applicable Indemnifying Party and Indemnified Party or that there may be one or more different or additional defenses, claims, counterclaims or causes of action available to such Indemnified 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 the reasonable fees and expenses of separate counsel shall be at the expense of the Indemnifying Party). It being understood, however, that the Indemnifying Party shall not, in connection with any one such Proceeding (including separate Proceedings that have been or will be consolidated before a single judge) be liable for the fees and expenses of more than one separate firm of attorneys at any time for all Indemnified Parties, which firm shall be appointed by a majority of the 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 reasonable 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 20 Trading Days of written notice thereof to the Indemnifying Party

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(regardless of whether it is ultimately determined that an Indemnified Party is not entitled to indemnification hereunder; provided, 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 (not subject to appeal) that such Indemnified Party is not entitled to indemnification hereunder).

(d) Contribution. If a claim for indemnification under Section 6.4(a) or (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 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 6.4(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 6.4(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 6.4(d) , no Investor shall be required to contribute, in the aggregate, any amount in excess of the amount by which the proceeds actually received by such Investor from the sale of the Registrable Securities subject to the Proceeding exceeds the amount of any damages that such Investor has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No Person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any Person who was not guilty of such fraudulent misrepresentation.

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.

6.5 Dispositions. Each Investor 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 and shall sell its Registrable Securities that it sells pursuant to the Registration Statement in accordance with the Plan of Distribution set forth in the Prospectus. Each Investor further agrees that, upon receipt of a notice from the Company of the occurrence of any event of the kind described in Section 6.2(c)(iv) or (v), such Investor will discontinue disposition of such Registrable Securities under the Registration Statement until such Investor is advised in writing by the Company that the use

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of the Prospectus, or amended Prospectus, as applicable, may be used. The Company may provide appropriate stop orders to enforce the provisions of this paragraph. Each Investor, severally and not jointly with the other Investors, agrees that the removal of the restrictive legend from certificates representing Securities as set forth in the Section 4.1 is predicated upon the Company’s reliance that the Investor will comply with the provisions of this subsection.

6.6 No Piggyback on Registrations. Neither the Company nor any of its security holders (other than the Investors in such capacity pursuant hereto and the Agent for any placement agent warrants issued as compensation for this offering) may include securities of the Company in the Registration Statement other than the Registrable Securities.

ARTICLE VII

MISCELLANEOUS

7.1 Termination. This Agreement may be terminated by the Company or any Investor, by written notice to the other parties, if the Closing has not been consummated by the third Business Day following the date of this Agreement; provided, however , that the right to terminate this Agreement under this Section 7.1 shall not be available to any Person whose failure to comply with its obligations under this Agreement has been the cause of or resulted in the failure of the Closing to occur on or before such time, and provided further that no such termination will affect the right of any party to sue for any breach by the other party (or parties) and shall not affect any provisions hereof that expressly survive termination in accordance with the terms hereof.

7.2 Fees and Expenses. Except as expressly set forth in the Transaction Documents to the contrary, each party shall pay the fees and expenses of its advisers, counsel, accountants and other experts, if any, and all other expenses incurred by such party incident to the negotiation, preparation, execution, delivery and performance of this Agreement. The Company shall pay all Transfer Agent fees, stamp taxes and other taxes and duties levied in connection with the sale and issuance of their applicable Securities.

7.3 Entire Agreement. The Transaction Documents, together with the Exhibits and Schedules thereto, contain the entire understanding of the parties with respect to the subject matter hereof and supersede all prior agreements and understandings, oral or written, with respect to such matters, which the parties acknowledge have been merged into such documents, exhibits and schedules. At or after the Closing, and without further consideration, the Company will execute and deliver to the Investors such further documents as may be reasonably requested in order to give practical effect to the intention of the parties under the Transaction Documents.

7.4 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 or email at the facsimile number or email address specified in this Section prior to 6:30 p.m. (New York City time) on a Trading Day, (b) the next Trading Day after the date of transmission, if such notice or communication is delivered via facsimile or email at the facsimile number or email address specified in this Section on a day that is not a Trading Day or later than 6:30 p.m. (New York City time) on any Trading Day, (c) the Trading Day following the date of

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deposit with a nationally recognized overnight courier service, or (d) upon actual receipt by the party to whom such notice is required to be given. The addresses, facsimile numbers and email addresses for such notices and communications are those set forth on the signature pages hereof, or such other address or facsimile number as may be designated in writing hereafter, in the same manner, by any such Person.

7.5 Amendments; Waivers. No provision of this Agreement may be waived or amended except in a written instrument signed, by the Company and the Investors holding the right to acquire at least sixty-one percent (61%) of the Registrable Securities on a fully-diluted basis at the time of such amendment. 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.

7.6 Construction. The headings herein are for convenience only, do not constitute a part of this Agreement and shall not be deemed to limit or affect any of the provisions hereof. The language used in this Agreement will be deemed to be the language chosen by the parties to express their mutual intent, and no rules of strict construction will be applied against any party.

7.7 Successors and Assigns. This Agreement shall be binding upon and inure to the benefit of the parties and their successors and permitted assigns. The Company may not assign this Agreement or any rights or obligations hereunder without the prior written consent of the Investors. Any Investor may assign its rights under this Agreement to any Person to whom such Investor assigns or transfers any Securities, provided (i) such transferor agrees in writing with the transferee or assignee to assign such rights, and a copy of such agreement is furnished to the Company after such assignment, (ii) the Company is furnished with written notice of (x) the name and address of such transferee or assignee and (y) the Registrable Securities with respect to which such registration rights are being transferred or assigned, (iii) following such transfer or assignment, the further disposition of such securities by the transferee or assignee is restricted under the Securities Act and applicable state securities laws, unless such disposition was made pursuant to an effective Registration Statement or an exemption under Rule 144 under the Securities Act, (iv) such transferee agrees in writing to be bound, with respect to the transferred Securities, by the provisions hereof that apply to the “Investors” and (v) such transfer shall have been made in accordance with the applicable requirements of this Agreement and with all laws applicable thereto.

7.8 Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the Company and each Investor and their respective successors and permitted assigns. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, other than those persons mentioned in the preceding sentence or otherwise explicitly mentioned in this Agreement, any legal or equitable right, remedy or claim under or in respect of this Agreement, or any provisions herein contained, this Agreement and all conditions and provisions hereof being intended to be and being for the sole and exclusive benefit of such persons and for the benefit of no other person.

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7.9 Governing Law; Venue; Waiver of Jury Trial. ALL QUESTIONS CONCERNING THE CONSTRUCTION, VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK. THE COMPANY AND INVESTORS HEREBY IRREVOCABLY SUBMIT TO THE NON-EXCLUSIVE JURISDICTION OF THE STATE AND FEDERAL COURTS SITTING IN THE CITY OF NEW YORK, BOROUGH OF MANHATTAN FOR THE ADJUDICATION OF ANY DISPUTE BROUGHT BY THE COMPANY OR ANY INVESTOR HEREUNDER, IN CONNECTION HEREWITH OR WITH ANY TRANSACTION CONTEMPLATED HEREBY OR DISCUSSED HEREIN (INCLUDING WITH RESPECT TO THE ENFORCEMENT OF ANY OF THE TRANSACTION DOCUMENTS), AND HEREBY IRREVOCABLY WAIVE, AND AGREE NOT TO ASSERT IN ANY SUIT, ACTION OR PROCEEDING BROUGHT BY THE COMPANY OR ANY INVESTOR, ANY CLAIM THAT IT IS NOT PERSONALLY SUBJECT TO THE JURISDICTION OF ANY SUCH COURT, OR THAT SUCH SUIT, ACTION OR PROCEEDING IS IMPROPER. EACH PARTY HEREBY IRREVOCABLY WAIVES PERSONAL SERVICE OF PROCESS AND CONSENTS TO PROCESS BEING SERVED IN ANY SUCH SUIT, ACTION OR 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 ANY RIGHT TO SERVE PROCESS IN ANY MANNER PERMITTED BY LAW. THE COMPANY AND INVESTORS HEREBY WAIVE ALL RIGHTS TO A TRIAL BY JURY.

7.10 Survival. The representations and warranties by the Company contained herein shall survive the Closing for a period of one (1) year from the Closing Date. The agreements and covenants contained herein shall survive for the applicable statute of limitations.

7.11 Execution. 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 email attachment, 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 email-attached signature page were an original thereof.

7.12 Severability. If any provision of this Agreement is prohibited by law or otherwise determined to be invalid or unenforceable by a court of competent jurisdiction, the provision that would otherwise be prohibited, invalid or unenforceable shall be deemed amended to apply to the broadest extent that it would be valid and enforceable, and the invalidity or unenforceability of such provision shall not affect the validity of the remaining provisions of this Agreement so long as this Agreement as so modified continues to express, without material change, the original intentions of the parties as to the subject matter hereof and the prohibited nature, invalidity or unenforceability of the provision(s) in question does not substantially impair the respective expectations or reciprocal obligations of the parties or the practical realization of

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the benefits that would otherwise be conferred upon the parties. The parties will endeavor in good faith negotiations to replace the prohibited, invalid or unenforceable provision(s) with a valid provision(s), the effect of which comes as close as possible to that of the prohibited, invalid or unenforceable provision(s).

7.13 Rescission and Withdrawal Right. Notwithstanding anything to the contrary contained in (and without limiting any similar provisions of) the Transaction Documents, whenever any Investor exercises a right, election, demand or option owed to such Investor by the Company under a Transaction Document and the Company does not timely perform its related obligations within the periods therein provided, then, prior to the performance by the Company of the Company’s related obligation, such Investor may rescind or withdraw, in its sole discretion from time to time upon written notice to the Company, any relevant notice, demand or election in whole or in part without prejudice to its future actions and rights.

7.14 Replacement of Securities. If any certificate or instrument evidencing any Securities is mutilated, lost, stolen or destroyed, the Company shall issue or cause to be issued in exchange and substitution for and upon cancellation thereof, or in lieu of and substitution therefor, a new certificate or instrument, but only upon receipt of evidence reasonably satisfactory to the Company of such loss, theft or destruction and the execution by the holder thereof of a customary lost certificate affidavit of that fact and an agreement to indemnify and hold harmless the Company for any losses in connection therewith. The applicants for a new certificate or instrument under such circumstances shall also pay any reasonable third-party costs associated with the issuance of such replacement Securities.

7.15 Remedies. In addition to being entitled to exercise all rights provided herein or granted by law, including recovery of damages, each of the Investors and the Company will be entitled to seek specific performance under the Transaction Documents. The parties agree that monetary damages may not be adequate compensation for any loss incurred by reason of any breach of obligations described in the foregoing sentence and hereby agrees to waive in any action for specific performance of any such obligation (other than in connection with any action for temporary restraining order) the defense that a remedy at law would be adequate.

7.16 Payment Set Aside. To the extent that the Company makes a payment or payments to any Investor hereunder or any Investor enforces or exercises its rights hereunder or thereunder, and such payment or payments or the proceeds of such enforcement or exercise or any part thereof are subsequently invalidated, declared to be fraudulent or preferential, set aside, recovered from, disgorged by or are required to be refunded, repaid or otherwise restored to the Company by a trustee, receiver or any other person under any law (including, without limitation, any bankruptcy law, state or federal law, common law or equitable cause of action), then to the extent of any such restoration the obligation or part thereof originally intended to be satisfied shall be revived and continued in full force and effect as if such payment had not been made or such enforcement or setoff had not occurred.

7.17 Adjustments in Share Numbers and Prices. In the event of any stock split, subdivision, dividend or distribution payable in shares of Common Stock (or other securities or rights convertible into, or entitling the holder thereof to receive directly or indirectly shares of Common Stock), combination or other similar recapitalization or event occurring after the date hereof and prior to the Closing, each reference in any Transaction Document to a number of shares or a price per share shall be amended to appropriately account for such event.

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7.18 Independent Nature of Investors’ Obligations and Rights. The obligations of each Investor under any Transaction Document are several and not joint with the obligations of any other Investor, and no Investor shall be responsible in any way for the performance of the obligations of any other Investor under any Transaction Document. The decision of each Investor to purchase Securities pursuant to this Agreement has been made by such Investor independently of any other Investor and independently of any information, materials, statements or opinions as to the business, affairs, operations, assets, properties, liabilities, results of operations, condition (financial or otherwise) or prospects of the Company which may have been made or given by any other Investor or by any agent or employee of any other Investor, and no Investor or any of its agents or employees shall have any liability to any other Investor (or any other person) relating to or arising from any such information, materials, statements or opinions. Nothing contained herein or in any Transaction Document, and no action taken by any Investor pursuant thereto, shall be deemed to constitute the Investors as a partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Investors are in any way acting in concert or as a group with respect to such obligations or the transactions contemplated by the Transaction Document. Each Investor acknowledges that no other Investor has acted as agent for such Investor in connection with making its investment hereunder and that no other Investor will be acting as agent of such Investor in connection with monitoring its investment hereunder. Each Investor shall be entitled to independently protect and enforce its rights, including without limitation the rights arising out of this Agreement or out of the other Transaction Documents, and it shall not be necessary for any other Investor to be joined as an additional party in any proceeding for such purpose.

7.19 Conflict Waiver. Each party to this Agreement acknowledges that Cooley LLP (“ Cooley ”), outside general counsel to the Company, has in the past performed and is or may now or in the future represent one or more Investors or their affiliates in matters unrelated to the transactions contemplated by this Agreement (the “ Financing ”), including representation of such Investors or their affiliates in matters of a similar nature to the Financing. The applicable rules of professional conduct require that Cooley inform the parties hereunder of this representation and obtain their consent. Cooley has served as outside general counsel to the Company and has negotiated the terms of the Financing solely on behalf of the Company. The Company and each of the Investors hereby (a) acknowledge that they have had an opportunity to ask for and have obtained information relevant to such representation, including disclosure of the reasonably foreseeable adverse consequences of such representation; (b) acknowledge that with respect to the Financing, Cooley has represented solely the Company, and not any Investor or any stockholder, director or employee of the Company or any Investor; and (c) gives its informed consent to Cooley’s representation of the Company in the Financing.

[ S IGNATURE P AGES TO F OLLOW ]

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I N W ITNESS W HEREOF , the parties hereto have caused this Securities Purchase Agreement to be duly executed by their respective authorized signatories as of the date first indicated above.

C OMPANY S IGNATURE P AGE

INVESTOR SIGNATURE PAGE

By its execution and delivery of this signature page, the undersigned Investor hereby joins in and agrees to be bound by the terms and conditions of the Securities Purchase Agreement dated as of                     , 2012 (the “Purchase Agreement”) by and among AcelRx Pharmaceuticals, Inc. and the Investors (as defined therein), as to the number of shares of Common Stock and Warrants set forth below, and authorizes this signature page to be attached to the Purchase Agreement or counterparts thereof.

Exhibits:

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Exhibit B

INSTRUCTION SHEET FOR INVESTOR

(to be read in conjunction with the entire Securities Purchase Agreement)

Provide the information requested by the Stock Certificate Questionnaire.

Provide the information requested by the Registration Statement Questionnaire.

Provide the information requested by the Investor Certificate.

Provide the information requested by the Securities Delivery Instructions.

Facsimile:

Email:

Telephone:

Attn:

Address:

Telephone:

Attn:

Exhibit B-1

AcelRx Pharmaceuticals, Inc.

STOCK CERTIFICATE QUESTIONNAIRE

Exhibit B-2

ACELRX PHARMACEUTICALS, INC.

REGISTRATION STATEMENT QUESTIONNAIRE

In connection with the Registration Statement, please provide us with the following information regarding the Investor.

1. Please state the Investor’s name exactly as it should appear in the Registration Statement:

Except as set forth below, the Investor does not hold any equity securities of the Company on behalf of another person or entity.

State any exceptions here:

If the Investor is not a natural person, please identify the natural person or persons who will have voting and investment control over the Registrable Securities owned by the Investor:

2. Address of the Investor:

3. Has the Investor had any position, office or other material relationship within the past three years with the Company or its affiliates? (Include any relationships involving the Investor or its affiliates, officers or directors that has held any position or office or has had any other material relationship with the Company (or its predecessors or affiliates) during the past three years.)

If yes, please indicate the nature of any such relationship below:

4. Except as set forth below in this Item 4, the Investor does not beneficially own (within the meaning of Rule 13d-3 under the Exchange Act) any securities of the Company.

(a) Number (and type) of Registrable Securities beneficially owned:

(b) Number (and type) of securities of the Company other than Registrable Securities beneficially owned:

(c) Number (and type) of Registrable Securities which the undersigned wishes to be included in the Registration Statement:

5. Except as set forth below in this Item 5, the Investor is not the beneficial or registered owner of any Registrable Securities or any other securities of the Company, other than the securities listed above in Item 4.

State any exceptions here:

6. Has the Investor made or is it aware of any arrangements relating to the distribution of the shares of the Company pursuant to the Registration Statement?

If yes, please describe the nature and amount of such arrangements.

State below whether the Investor is a member of FINRA.

This response to Item 7(a) is made only with respect to the Investor, its general partner and any limited partners with a 10% or greater interest in the Investor.

State below whether (i) any associate or affiliate of the Investor is a member of FINRA, a controlling shareholder of a FINRA member, a person associated with a member, a direct or indirect affiliate of a member, or an underwriter or related person with respect to the proposed offering; (ii) the Investor or any associate or affiliate of the Investor owns any stock or other securities of any FINRA member not purchased in the open market; or (iii) the Investor or any associate or affiliate of the Investor has made any outstanding subordinated loans to any FINRA member. If the Investor is a general or limited partnership, a no answer asserts that no such relationship exists for the Investor as well as for each of its general partners.

This response to Item 7(b) is made only with respect to the Investor and its general partner.

If “yes,” please identify the FINRA member and describe the Investor’s relationship, including, in the case of a general or limited partner, the name of the partner:

(c) If the answer to Item 7 (b) is yes, did the Investor acquire the Registrable Securities in the ordinary course of business (if not, please explain)?

(d) If the answer to Item 7(b) is yes, did the Investor, at the time of purchase of the Registrable Securities, have any agreements, plans or understandings, directly or indirectly, with any person to distribute the Registrable Securities (if yes, please explain)?

If the Investor answered “no” to Question 7(a) and 7(b), it need not respond to Question 7(e).

Note that in general we will be required to identify any registered broker-dealer as an underwriter in the Registration Statement. Note that if the Investor is an associate or affiliate of a broker-dealer and did not purchase the Registrable Securities in the ordinary course of business or at the time of purchase had any arrangements or understandings, directly or indirectly, to distribute the securities, the Investor may be required to be identified as an underwriter in the Registration Statement.

(e) State below whether the Investor or any associate or affiliate of the Investor has been an underwriter, or a controlling person or member of any investment banking or brokerage firm which has been or might be an underwriter for securities of the Corporation or any affiliate thereof including, but not limited to, the common stock now being registered.

If “yes,” please identify the FINRA member and describe your relationship, including, in the case of a general or limited partner, the name of the partner.

ACKNOWLEDGEMENT

The undersigned hereby agrees to notify the Company promptly of any changes in the foregoing information (other than with respect to Items 4, 5 or 6) which should be made as a result of any developments, including the passage of time. The undersigned also agrees to provide the Company and the Company’s counsel any and all such further information regarding the undersigned promptly upon request in connection with the preparation, filing, amending, and supplementing of the Registration Statement (or any prospectus contained therein). The undersigned hereby consents to the use of all such information in the Registration Statement.

The undersigned understands and acknowledges that the Company will rely on the information set forth herein for purposes of the preparation and filing of the Registration Statement.

The undersigned understands that the undersigned may be subject to serious civil and criminal liabilities if the Registration Statement, when it becomes effective, either contains an untrue statement of a material fact or omits to state a material fact required to be stated in the Registration Statement or necessary to make the statements in the Registration Statement not misleading. The undersigned represents and warrants that all information it provides to the Company and its counsel is currently accurate and complete and will be accurate and complete at the time the Registration Statement becomes effective and at all times subsequent thereto, and agrees during the Effectiveness Period and any additional period in which the undersigned is making sales of Shares under and pursuant to the Registration Statement, and agrees during such periods to notify the Company immediately of any misstatement of a material fact in the Registration Statement, and of the omission of any material fact necessary to make the statements contained therein not misleading.

Exhibit B-3

ACELRX PHARMACEUTICALS, INC.

CERTIFICATE FOR CORPORATE, PARTNERSHIP, LIMITED LIABILITY COMPANY, TRUST, FOUNDATION AND JOINT INVESTORS

If the investor is a corporation, partnership, limited liability company, trust, pension plan, foundation, joint Investor (other than a married couple) or other entity, an authorized officer, partner, or trustee must complete, date and sign this Certificate.

CERTIFICATE

The undersigned certifies that the representations and responses below are true and accurate:

(a) The investor has been duly formed and is validly existing and has full power and authority to invest in the Company. The person signing on behalf of the undersigned has the authority to execute and deliver the Securities Purchase Agreement on behalf of the Investor and to take other actions with respect thereto.

(b) Indicate the form of entity of the undersigned:

           Limited Partnership

           General Partnership

           Limited Liability Company

           Corporation

           Revocable Trust (identify each grantor and indicate under what circumstances the trust is revocable by the grantor):

(Continue on a separate piece of paper, if necessary.)

           Other type of Trust (indicate type of trust and, for trusts other than pension trusts, name the grantors and beneficiaries):                                                                                                                                                                                                                                            

(Continue on a separate piece of paper, if necessary.)

           Other form of organization (indicate  form of organization (                                                                                                    

(c) Indicate the approximate date the undersigned entity was formed:                                                                                                  .

(d) In order for the Company to offer and sell the Securities in conformance with state and federal securities laws, the following information must be obtained regarding your investor status. Please initial each category applicable to you as an investor in the Company.

(e) Please set forth your principal address.

$         

Dated:                    , 2012

Exhibit B-4

SECURITIES DELIVERY INSTRUCTIONS

Please instruct us as to where you would like the Securities delivered to at Closing:

Exhibit C

OPINION OF C O MPANY CORPORATE COUNSEL

Exhibit D

PLAN OF DISTRIBUTION

The selling stockholders may, from time to time, sell any or all of their shares of common stock on any stock exchange, market or trading facility on which the shares are traded or in private transactions. These sales may be at fixed or negotiated prices. The selling stockholders may use any one or more of the following methods when selling shares:

The selling stockholders also may resell all or a portion of the shares in open market transactions in reliance upon Rule 144 under the Securities Act, as permitted by that rule, or Section 4(1) under the Securities Act, if available, rather than under this prospectus, provided that they meet the criteria and conform to the requirements of those provisions.

Broker-dealers engaged by the selling stockholders may arrange for other brokers-dealers to participate in sales. Broker-dealers may receive commissions or discounts from the selling stockholders (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. The selling stockholders do not expect these commissions and discounts to exceed what is customary in the types of transactions involved. Any profits on the resale of shares of common stock by a broker-dealer acting as principal might be deemed to be underwriting discounts or commissions under the Securities Act. Discounts, concessions, commissions and similar selling expenses, if any, attributable to the sale of shares will be borne by a selling stockholder. The selling stockholders may agree to indemnify any agent, dealer or broker-dealer that participates in transactions involving sales of the shares if liabilities are imposed on that person under the Securities Act.

The selling stockholders may from time to time pledge or grant a security interest in some or all of the shares of common stock owned by them and, if they default in the performance of their secured obligations, the pledgees or secured parties may offer and sell the shares of common stock from time to time under this prospectus after we have filed a supplement to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act of 1933 supplementing or amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders under this prospectus.

The selling stockholders also may transfer the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus and may sell the shares of common stock from time to time under this prospectus after we have filed a supplement to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act of 1933 supplementing or amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders under this prospectus.

The selling stockholders and any broker-dealers or agents that are involved in selling the shares of common stock may be deemed to be “underwriters” within the meaning of the Securities Act in connection with such sales. In such event, any commissions received by such broker-dealers or agents and any profit on the resale of the shares of common stock purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act.

We are required to pay all fees and expenses incident to the registration of the shares of common stock. We have agreed to indemnify the selling stockholders against certain losses, claims, damages and liabilities, including liabilities under the Securities Act.

The selling stockholders have advised us that they have not entered into any agreements, understandings or arrangements with any underwriters or broker-dealers regarding the sale of their shares of common stock, nor is there an underwriter or coordinating broker acting in connection with a proposed sale of shares of common stock by any selling stockholder. If we are notified by any selling stockholder that any material arrangement has been entered into with a broker-dealer for the sale of shares of common stock, if required, we will file a supplement to this prospectus. If the selling stockholders use this prospectus for any sale of the shares of common stock, they will be subject to the prospectus delivery requirements of the Securities Act.

The anti-manipulation rules of Regulation M under the Securities Exchange Act of 1934 may apply to sales of our common stock and activities of the selling stockholders.

Exhibit E

COMPANY TRANSFER AGENT INSTRUCTIONS

Computershare, Inc.

Attention:

Ladies and Gentlemen:

Reference is made to that certain Securities Purchase Agreement, dated as of May 29, 2012 (the “ Agreement ”), by and among AcelRx Pharmaceuticals, Inc., a Delaware corporation (the “ Company ”), and the investors named on the Schedule of Investors attached thereto (collectively, the “ Holders ”), pursuant to which the Company is issuing to the Holders shares (the “ Common Shares ”) of Common Stock of the Company, par value $0.001 per share (the “ Common Stock ”) and Warrants (the “ Warrants ”), which are exercisable into shares of Common Stock.

This letter shall serve as our irrevocable authorization and direction to you (provided that you are the transfer agent of the Company at such time):

(i) to issue shares of Common Stock upon transfer or resale of the Common Shares;

(ii) to reserve for issuance upon exercise of the Warrants 2,630,103 shares of the Company’s authorized and unissued shares of Common Stock; and

(iii) to issue shares of Common Stock upon the exercise of the Warrants (the “ Warrant Shares ”) to or upon the order of a Holder from time to time upon delivery to you of a properly completed and duly executed Exercise Notice, in the form attached hereto as Exhibit I , which has been acknowledged by the Company as indicated by the signature of a duly authorized officer of the Company thereon.

You acknowledge and agree that so long as you have previously received (a) written confirmation from the Company’s legal counsel that either (i) a registration statement covering resales of the Common Shares and the Warrant Shares has been declared effective by the Securities and Exchange Commission (the “ SEC ”) under the Securities Act of 1933, as amended (the “ Securities Act ”) and that resales of the Common Shares and the Warrant Shares may be made thereunder, or (ii) sales of the Common Shares and the Warrant Shares may be made in conformity with Rule 144 under the Securities Act (“ Rule 144 ”) without restrictions, (b) if applicable, a copy of such registration statement, and (c) notice from legal counsel to the Company or any Holder (including customary documentation from a Holder’s broker with respect to a sale pursuant to Rule 144) that a transfer of Common Shares and/or Warrant Shares has been effected either pursuant to the registration statement (and a prospectus delivered to the transferee) or pursuant to Rule 144, then, unless otherwise required by law, within three (3) business days of your receipt of the notice referred to in (c), you shall issue the certificates representing the Common Shares and the Warrant Shares so sold to the transferees registered in the names of such transferees, and such certificates shall not bear any legend restricting transfer of the Common Shares and the Warrant Shares thereby and should not be subject to any stop-transfer restriction.

In the event that you have not received the documentation required pursuant to clause (a) or (c) of the immediately preceding paragraph or such Shares and Warrant Shares are not eligible for sale without restriction in conformity with Rule 144 under the Securities Act, then the certificates for such Shares and/or Warrant Shares shall bear the following legend:

THESE SECURITIES HAVE NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ SECURITIES ACT ”), OR ANY APPLICABLE STATE SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN COMPLIANCE WITH APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS.

Please be advised that the Holders are relying upon this letter as an inducement to enter into the Agreement and, accordingly, each Holder is a third party beneficiary to these instructions.

Please execute this letter in the space indicated to acknowledge your agreement to act in accordance with these instructions. Should you have any questions concerning this matter, please contact me at [            ].

THE FOREGOING INSTRUCTIONS ARE

ACKNOWLEDGED AND AGREED TO

this      day of                     , 2012

EXHIBIT I

EXERCISE NOTICE

TO BE EXECUTED BY THE REGISTERED HOLDER TO EXERCISE THIS

WARRANT TO PURCHASE COMMON STOCK

AcelRx Pharmaceuticals, Inc.

The undersigned holder hereby exercises the right to purchase                      of the Common Stock (“ Warrant Shares ”) of AcelRx Pharmaceuticals, Inc., a company organized under the laws of the state of Delaware (the “ Company ”), evidenced by the attached Warrant to Purchase Common Stock (the “ Warrant ”). Capitalized terms used herein and not otherwise defined shall have the respective meanings set forth in the Warrant.

1. Form of Exercise Price. The Holder intends that payment of the Exercise Price shall be made as:

                       a “ Cash Exercise ” with respect to                      Warrant Shares; and/or

                       a “ Cashless Exercise ” with respect to                      Warrant Shares.

2. Payment of Exercise Price. In the event that the holder has elected a Cash Exercise with respect to some or all of the Warrant Shares to be issued pursuant hereto, the holder shall pay the Aggregate Exercise Price in the sum of $         to the Company in accordance with the terms of the Warrant.

3. Delivery of Warrant Shares. The Company shall deliver to the holder                      Warrant Shares in accordance with the terms of the Warrant.

4. Notwithstanding anything to the contrary contained herein, this Exercise Notice shall constitute a representation by the Holder of the Warrant submitting this Exercise Notice that either (i) such Holder is an Excluded AP Holder (as defined in the Warrant) or (ii) after giving effect to the exercise provided for in this Exercise Notice, such Holder (together with its affiliates) will not have beneficial ownership (together with the beneficial ownership of such Person’s affiliates) of a number of shares of Common Stock which exceeds the Applicable Percentage (as defined in the Warrant) of the total outstanding shares of Common Stock of the Company as determined pursuant to the provisions of Section 1(f)(i)(A) of the Warrant.