PHARMASSET, INC. COMMON STOCK (PAR VALUE $0.001 PER SHARE) PLACEMENT AGENCY AGREEMENT

Exhibit 10.1

4,678,000 Shares

PHARMASSET, INC.

COMMON STOCK (PAR VALUE $0.001 PER SHARE)

PLACEMENT AGENCY AGREEMENT

January 29, 2009

Leerink Swann LLC

One Federal Street, 37 ^th Floor

Boston, MA 02110

Ladies and Gentlemen:

This Agreement confirms our understanding that Pharmasset, Inc., a Delaware corporation (the “ Company ”), hereby appoints Leerink Swann LLC as its exclusive placement agent (the “ Placement Agent ”) in connection with the proposed sale to certain investors (the “ Direct Offering ”) of 4,678,000 shares of its Common Stock par value $0.001 per share (the “ Shares ”). On the basis of the representations and warranties contained herein, but subject to the terms and conditions set forth herein, the Placement Agent agrees to use its best commercially practicable efforts to solicit and receive offers to purchase the Shares. Until the Closing Date (as defined below), the Company shall not, without the prior written consent of the Placement Agent, solicit or accept offers to purchase Shares otherwise than through the Placement Agent. Notwithstanding anything to the contrary contained in this Agreement, the Placement Agent shall have no obligation to purchase any of the Shares, or any liability to the Company if any prospective purchaser fails to consummate a purchase of any of the Shares. In soliciting the purchases of Shares, the Placement Agent shall act solely as the Company’s agent and not as principal. The shares of Common Stock, par value $0.001 per share, of the Company are hereinafter referred to as the “ Common Stock. ”

Subject to the provisions of this Agreement, offers for the purchase of Shares may be solicited by the Placement Agent as agent for the Company at such time and in such amounts as the Placement Agent deems advisable. The Company shall have the sole right to accept offers to purchase the Shares and may reject any such offer, in whole or in part. The purchase of the Shares by investors in the Direct Offering shall be evidenced by the execution of a definitive subscription agreement (the “ Purchase Agreement ”) between the Company and each purchaser (each, a “ Purchaser ” and, collectively, the “ Purchasers ”) of the Shares.

The Company has filed with the Securities and Exchange Commission (the “ Commission ”) a registration statement, including a prospectus, (the file number of which is set forth in Schedule I hereto) on Form S-3, relating to the securities (the “ Shelf Securities ”), including the Shares, to be issued from time to time by the Company. The registration statement as amended to the date of this Agreement, including the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A or Rule 430B under the Securities Act of 1933, as amended (the “ Securities Act ”), is hereinafter referred to as the “ Registration Statement ”, and the related prospectus covering the Shelf Securities dated June 26, 2008 in the form first used to confirm sales of the Shares (or in the form first made available to the Placement Agent by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “ Basic Prospectus. ” The Basic Prospectus,

as supplemented by the prospectus supplement specifically relating to the Shares in the form first used to confirm sales of the Shares (or in the form first made available to the Placement Agent by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “ Prospectus ,” and the term “ preliminary prospectus ” means any preliminary form of the Prospectus. For purposes of this Agreement, “ free writing prospectus ” has the meaning set forth in Rule 405 under the Securities Act, “ Time of Sale Prospectus ” means the Basic Prospectus together with the free writing prospectuses, if any, each identified in Schedule I hereto, and “ broadly available road show ” means a “bona fide electronic road show” as defined in Rule 433(h)(5) under the Securities Act that has been made available without restriction to any person. As used herein, the terms “Registration Statement,” “Basic Prospectus,” “preliminary prospectus,” “Time of Sale Prospectus” and “Prospectus” shall include the documents, if any, incorporated by reference therein. The terms “ supplement ,” “ amendment ,” and “ amend ” as used herein with respect to the Registration Statement, the Basic Prospectus, the Time of Sale Prospectus, any preliminary prospectus or free writing prospectus shall include all documents subsequently filed by the Company with the Commission pursuant to the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), that are deemed to be incorporated by reference therein.

Concurrently with the execution and delivery of this Agreement, the Company, the Placement Agent and JPMorgan Chase Bank, N.A., as escrow agent (the “ Escrow Agent ”), shall enter into an escrow agreement (the “ Escrow Agreement ”), pursuant to which an escrow account (the “ Escrow Account ”) will be established for the benefit of the Company and the Purchasers. Prior to the completion of the purchase and sale of the Shares pursuant to this Agreement and the Purchase Agreements (the “ Closing ”), each such Purchaser shall deposit into the Escrow Account or, with the prior consent of the Company and the Placement Agent, make alternative arrangements for the payment directly to the Company of, an amount equal to the product of (x) the number of Shares such Purchaser has agreed to purchase and (y) the purchase price per Share as set forth in the Purchase Agreements (as defined below) (the “ Purchase Amount ”). The aggregate of such Purchase Amounts deposited with the Escrow Agent is herein referred to as the “ Escrow Funds .” On the Closing Date, upon satisfaction or waiver of all of the conditions to Closing, (i) the Escrow Agent will disburse the Escrow Funds to the Company and the Placement Agent as provided in the Escrow Agreement and Section 2 below, (ii) the Company shall cause the Shares to be delivered to the Purchasers who have deposited their Purchase Amounts with the Escrow Agent, and (iii) the Company and any Purchaser who has made, with the consent of the Company and the Placement Agent, alternative arrangements for the payment directly to the Company of the applicable Purchase Price, shall consummate the transactions contemplated hereby in accordance with such alternative arrangements.

Subject to the terms and conditions hereof, delivery of the Shares shall be made by the Company to the Purchasers, and payment of the purchase price shall be made by the Purchasers through the Escrow Agent, at the office of Wilmer Cutler Pickering Hale and Dorr LLP, 60 State Street, Boston, Massachusetts 02109 (or at such other place as agreed upon by the Placement Agent and the Company), at 10:00 a.m., New York City time, on or before February 4, 2009 or at such time on such other date as may be agreed

upon in writing by the Company and the Placement Agent but in no event prior to the date on which the Escrow Agent shall have received all of the Escrow Funds to be paid to the Company through the Escrow Agent (such date of delivery and payment is hereinafter referred to as the “ Closing Date ”); provided that the Company, the Placement Agent and a Purchaser may agree as to an alternative arrangement for the payment directly to the Company of the applicable purchase price for the Shares to be purchased by such Purchaser. The Shares shall be delivered, through the facilities of The Depository Trust Company, to such persons, and shall be registered in such name or names and shall be in such denominations, as the Placement Agent may request by written notice to the Company prior to the Closing Date. The cost of original issue tax stamps and other transfer taxes, if any, in connection with the issuance and delivery of the Shares by the Company to the respective Purchasers shall be borne by the Company.

1. Representations and Warranties . The Company represents and warrants to and agrees with the Placement Agent that:

(a) The Registration Statement has become effective, no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose are pending before or, to the Company’s knowledge, threatened by the Commission.

(b) (i) Each document, if any, filed or to be filed pursuant to the Exchange Act and incorporated by reference in the Time of Sale Prospectus or the Prospectus complied or will comply when so filed in all material respects with the Exchange Act and the applicable rules and regulations of the Commission thereunder, (ii) each part of the Registration Statement, when such part became effective, did not contain, and each such part, as amended or supplemented, if applicable, will not contain any 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 not misleading, (iii) the Registration Statement as of the date hereof does not contain any 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 not misleading, (iv) the Registration Statement and the Prospectus comply, and as amended or supplemented, if applicable, will comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (v) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the Direct Offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 2(a)), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (vi) each broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (vii) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and warranties set forth in this paragraph do not apply to statements or omissions in the Registration Statement, the Time of Sale Prospectus or the Prospectus based upon information relating to the Placement Agent furnished to the Company in writing by the Placement Agent expressly for use therein.

(c) The Company is not an “ineligible issuer” in connection with the Direct Offering pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule I hereto forming part of the Time of Sale Prospectus, and electronic road shows, if any, each furnished to the Placement Agent before first use, the Company has not prepared, used or referred to, and will not, without the prior consent of the Placement Agent, prepare, use or refer to, any free writing prospectus.

(d) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation and has corporate power and authority to own or lease, as the case may be, and operate its properties and to conduct its business as described in the Time of Sale Prospectus and the Prospectus and to enter into and perform its obligations under this Agreement. The Company is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except for such jurisdictions where the failure to so qualify or to be in good standing would not, individually or in the aggregate, result in a material adverse effect, on the condition, financial or otherwise, or on the earnings, business, properties, operations or prospects, whether or not arising from transactions in the ordinary course of business of the Company (a “ Material Adverse Effect ”).

(e) The Company has no subsidiaries.

(f) Except for the Current Report on Form 8-K filed by the Company with the Commission on January 22, 2009 (the “ January Report ”), the Company has filed in a timely manner all reports required to be filed pursuant to Sections 13(a), 13(e), 14 and 15(d) of the Exchange Act (except to the extent that Section 15(d) requires reports to be filed pursuant to Sections 13(d) and 13(g) of the Exchange Act, which shall be governed by the next clause of this sentence); the Company has filed in a timely manner all reports required to be filed pursuant to Sections 13(d) and 13(g) of the Exchange Act; and the failure to file the January Report in a timely manner under the Exchange Act does not and will not impair the ability of the Company to use the Registration Statement.

(g) The Company has not distributed and will not distribute, prior to the later of the Closing Date (as defined below) and the completion of the Placement Agent’s placement of the Shares, any offering material in connection with the placement of the Shares other than the Prospectus, any Issuer Free Writing Prospectus reviewed and consented to by the Placement Agent or included in Schedule I hereto or the Registration Statement.

(h) This Agreement has been duly authorized, executed and delivered by the Company.

(i) The authorized, issued and outstanding capital stock of the Company is as set forth in each of the Time of Sale Prospectus and the Prospectus. The Common Stock (including the Shares) conforms in all material respects to the description thereof contained in each of the Time of Sale Prospectus and the Prospectus. All of the issued and outstanding shares of Common Stock have been duly authorized and validly issued, are fully paid and nonassessable and have been issued in compliance with federal and state securities laws. None of the outstanding shares of Common Stock were issued in violation of any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. There are no Company authorized or outstanding options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or debt securities convertible into or exchangeable or exercisable for, any capital stock of the Company, other than those described in the Time of Sale Prospectus and the Prospectus or options granted under the Company’s 2007 Equity Incentive Plan. The description of the Company’s stock option, stock bonus and other stock plans or arrangements, and the options or other rights granted thereunder, set forth in each of the Time of Sale Prospectus and the Prospectus accurately and fairly presents in all material respects the information required to be shown with respect to such plans, arrangements, options and rights.

(j) The Company has filed in a timely manner a Notification Form: Listing of Additional Shares relating to the Shares with The NASDAQ Stock Market, LLC (“ NASDAQ ”). The Common Stock is registered under Section 12(b) of the Exchange Act and is listed on the NASDAQ Global Market.

(k) The Shares to be placed by the Placement Agent on behalf of the Company have been duly authorized for issuance and sale pursuant to any applicable Purchase Agreement and, when issued and delivered by the Company to prospective Purchasers, against payment of the applicable Purchase Price therefor, pursuant to any applicable Purchase Agreement on the Closing Date, will be validly issued, fully paid and nonassessable.

(l) The Company is not (i) in violation or in default (or, with the giving of notice or lapse of time, would be in default) (“ Default ”) under its certificate of incorporation or by-laws, (ii) in Default under any indenture, mortgage, loan or credit agreement, deed of trust, note, contract, franchise, lease or other agreement, obligation, condition, covenant or instrument to which the Company is a party or by which it may be bound, or to which any of the property or assets of the Company is subject (each, an “ Existing Instrument ”), or (iii) in violation of any statute, law, rule, regulation, judgment, order or decree of any court, regulatory body,

administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or any of its properties, as applicable, except with respect to clause (ii) and (iii) only, for such Defaults as would not, individually or in the aggregate, have a Material Adverse Effect. The Company’s execution, delivery and performance of this Agreement and the Escrow Agreement and consummation of the transactions contemplated hereby, thereby, by the Time of Sale Prospectus and by the Prospectus (i) have been duly authorized by all necessary corporate action and will not result in any Default under the certificate of incorporation or by-laws of the Company, (ii) will not conflict with or constitute a breach of, or Default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to, or require the consent of any other party to, any Existing Instrument, and (iii) will not result in any violation of any statute, law, rule, regulation, judgment, order or decree applicable to the Company of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or any of its or their properties. No consent, approval, authorization or other order of, or registration or filing with, any court or other governmental or regulatory authority or agency is required for the Company’s execution, delivery and performance of this Agreement and the Escrow Agreement and consummation of the transactions contemplated hereby, thereby, by the Time of Sale Prospectus and by the Prospectus, except such as have been obtained or made by the Company and are in full force and effect under the Securities Act, applicable state securities or blue sky laws, with NASDAQ and from the Financial Industry Regulatory Authority, Inc. (“ FINRA ”).

(m) Except as otherwise disclosed in the Time of Sale Prospectus and the Prospectus, subsequent to the respective dates as of which information is given in the Time of Sale Prospectus: (i) there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business, properties, operations or prospects, whether or not arising from transactions in the ordinary course of business of the Company; (ii) the Company has not incurred any material liability or obligation, indirect, direct or contingent, nor entered into any material transaction or agreement; and (iii) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of capital stock or repurchase or redemption by the Company of any class of capital stock.

(n) There are no legal or governmental actions, suits or proceedings pending or, to the best of the Company’s knowledge, threatened (i) against or affecting the Company, (ii) which has as the subject thereof any officer or director of, or property owned or leased by, the Company or (iii) relating to environmental or discrimination matters which would, individually or in the aggregate, have a Material Adverse Effect or adversely affect the consummation of the transactions contemplated by this Agreement.

(o) The Company is not, and after giving effect to the transactions contemplated hereby, by the Time of Sale Prospectus and by the Prospectus will not be, required to be registered as an “investment company” within the meaning of the Investment Company Act of 1940, as amended (the “ Investment Company Act ”).

(p) Except as otherwise disclosed in the Time of Sale Prospectus and the Prospectus, (i) the Company is not in violation of any federal, state, local or foreign law, regulation, order, permit or other requirement relating to pollution or protection of human health or the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including without limitation, laws and regulations relating to emissions, discharges, releases or threatened releases of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum and petroleum products (collectively, “ Materials of Environmental Concern ”), or otherwise relating to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Materials of Environment Concern (collectively, “ Environmental Laws ”), which violation includes, but is not limited to, noncompliance with any permits or other governmental authorizations required for the operation of the business of the Company under applicable Environmental Laws, or noncompliance with the terms and conditions thereof, nor has the Company received any written communication, whether from a governmental authority, citizens group, employee or otherwise, that alleges that the Company is in violation of any Environmental Laws, except as would not, individually or in the aggregate, have a Material Adverse Effect; (ii) there is no claim, action or cause of action filed with a court or governmental authority, no investigation with respect to which the Company has received written notice, and no written notice by any person or entity alleging potential liability for investigatory costs, cleanup costs, governmental responses costs, natural resources damages, property damages, personal injuries, attorneys’ fees or penalties arising out of, based on or resulting from the presence, or release into the environment, of any Material of Environmental Concern at any location owned, leased or operated by the Company, now or in the past (collectively, “ Environmental Claims ”), pending or, to the Company’s knowledge, threatened against the Company or any person or entity whose liability for any Environmental Claim the Company has retained or assumed either contractually or by operation of law, except as would not, individually or in the aggregate, have a Material Adverse Effect; (iii) to the Company’s knowledge, there are no past or present actions, activities, conditions, events or incidents, including, without limitation, the release, emission, discharge, presence or disposal of any Material of Environmental Concern, that reasonably could result in a violation of any Environmental Laws, require expenditures to be incurred pursuant to Environmental Laws, or form the basis of a potential Environmental Claim against the Company or against any person or entity whose liability for any Environmental Claim the Company has retained or assumed either contractually or by operation of law, except as would not, individually or in the aggregate, have a Material Adverse Effect; and (iv) the Company is not subject to any pending or, to the Company’s knowledge, threatened proceeding under Environmental Law to which a governmental authority is a party and which is reasonably likely to result in monetary sanctions of $100,000 or more.

(q) None of the following events has occurred or exists: (i) a failure to fulfill the obligations, if any, under the minimum funding standards of Section 302 of the United States Employee Retirement Income Security Act of 1974, as amended (“ ERISA ”), and the regulations and published interpretations thereunder with respect to a Plan, determined without regard to any waiver of such obligations or extension of any amortization period; (ii) an audit or investigation by the Internal Revenue Service, the U.S. Department of Labor, the Pension Benefit Guaranty Corporation or any other federal or state governmental agency or any foreign

regulatory agency with respect to the employment or compensation of employees by any member of the Company that could have a Material Adverse Effect; (iii) any breach of any contractual obligation, or any violation of law or applicable qualification standards, with respect to the employment or compensation of employees by any member of the Company that could have a Material Adverse Effect. None of the following events has occurred or is reasonably likely to occur: (i) a material increase in the aggregate amount of contributions required to be made to all Plans in the current fiscal year of the Company compared to the amount of such contributions made in the Company’s most recently completed fiscal year; (ii) a material increase in the Company’s “accumulated post-retirement benefit obligations” (within the meaning of Statement of Financial Accounting Standards 106) compared to the amount of such obligations in the Company’s most recently completed fiscal year; (iii) any event or condition giving rise to a liability under Title IV of ERISA that could have a Material Adverse Effect; or (iv) the filing of a claim by one or more employees or former employees of the Company related to their employment that could have a Material Adverse Effect. For purposes of this paragraph, the term “ Plan ” means a plan (within the meaning of Section 3(3) of ERISA) subject to Title IV of ERISA with respect to which any member of the Company may have any liability.

(r) There are no persons with registration or other similar rights to have any equity or debt securities registered for sale under the Registration Statement or included in the offering contemplated by this Agreement, except for such rights as have been duly waived.

(s) Neither the Company nor, to the knowledge of the Company, any director, officer, or employee of the Company is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “ FCPA ”), including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA, and the Company has conducted its business in compliance with the FCPA.

(t) To the Company’s knowledge, the statistical and market-related data included or incorporated by reference in the Registration Statement, the Time of Sale Prospectus or the Prospectus is based on or derived from sources that are materially reliable and accurate.

(u) The preclinical and clinical studies and tests conducted by or on behalf of the Company that are described in the Registration Statement, the Time of Sale Prospectus or the Prospectus or the results of which are referred to in the Registration Statement, the Time of Sale Prospectus or the Prospectus, were and, if still pending, are being conducted in all material respects in accordance with experimental protocols, procedures and controls generally used by qualified experts in the preclinical and clinical study (as applicable) of new drugs or diagnostics as applied to products comparable to those being developed by the Company. The descriptions of the results of the preclinical and clinical studies and tests contained in the Registration Statement, the Time of Sale Prospectus or the Prospectus are accurate and complete in all material respects.

(v) The Company has (i) orally, to the Placement Agent or to counsel to the Placement Agent, fairly summarized in all material respects the substance of all of its material communications with representatives of the FDA; and (ii) no knowledge of any pending communication from the FDA that would cause the Company to revise its strategy for seeking marketing approval from the FDA for any of the Company’s products under development as described in the Registration Statement, the Time of Sale Prospectus or the Prospectus.

(w) There are no transfer taxes or other similar fees or charges under federal law or the laws of any state, or any political subdivision thereof, required to be paid in connection with the execution and delivery of this Agreement or the issuance by the Company or sale by the Company of the Shares.

(x) Grant Thornton LLP (“ Grant Thornton ”), who have expressed their opinion with respect to the financial statements (which term as used in this Agreement includes the related notes thereto) and supporting schedules, if any, filed with the Commission as a part of the Registration Statement and included in the Time of Sale Prospectus and the Prospectus, are independent public accountants with respect to the Company as required by the Securities Act and the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”) and the applicable rules and regulations thereunder.

(y) The financial statements filed with the Commission as a part of the Registration Statement and included in the Time of Sale Prospectus and the Prospectus present fairly in all material respects the financial condition of the Company as of and at the dates indicated and the results of its operations and cash flows for the periods specified on the basis stated therein. Such financial statements comply as to form with the applicable accounting requirements of the Securities Act and have been prepared in conformity with generally accepted accounting principles applied on a consistent basis throughout the periods involved, except as may be expressly stated in the related notes thereto. No other financial statements or supporting schedules are required to be included in the Registration Statement.

(z) No labor dispute with the employees of the Company exists or, to the Company’s knowledge, is threatened or imminent, and the Company is not aware of any existing or imminent labor dispute with the employees of any of its principal suppliers that could have a Material Adverse Effect.

(aa) Except as described in the Time of Sale Prospectus and the Prospectus, the Company owns, possesses, licenses or has other rights to use, on reasonable terms, all patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights, licenses, inventions, trade secrets, technology, know-how and other intellectual property (collectively, the “ Intellectual Property ”) that are necessary for the conduct of the Company’s business as now conducted or, in connection with its major product candidates, as proposed in each of the Time of Sale Prospectus and the Prospectus to be conducted. Except as set forth

in the Time of Sale Prospectus and the Prospectus, (i) to the Company’s knowledge, there is no material infringement by third parties of any such Intellectual Property owned by or exclusively licensed to the Company; (ii) 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 Intellectual Property that would have a Material Adverse Effect; (iii) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the validity or scope of any Intellectual Property that would have a Material Adverse Effect; (iv) to the Company’s knowledge there is no pending or, threatened action, suit, proceeding or claim by others that the Company’s business as now conducted infringes or otherwise violates any patent, trademark, copyright, trade secret or other proprietary rights of others; (v) to the Company’s knowledge the Company has complied in all material respects with the terms of each agreement pursuant to which material Intellectual Property has been licensed to the Company, and all such agreements are in full force and effect; and (vi) to the Company’s knowledge, the product candidates described in the Time of Sale Prospectus and the Prospectus, if any, as under development by the Company fall within the scope of the claims of one or more patents or patent applications owned by, or exclusively licensed to, the Company, and nothing has come to the Company’s attention that causes it to believe that such patents are not valid or enforceable.

(bb) The Company possesses such valid and current licenses, certificates, authorizations or permits issued by the appropriate state, federal or foreign regulatory agencies or bodies necessary to conduct its business which, singly or in the aggregate, if not obtained, would have a Material Adverse Effect, and the Company has not received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such license, certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, could have a Material Adverse Effect.

(cc) Except as set forth in the Time of Sale Prospectus and the Prospectus, the Company has good and marketable title to all the properties and assets reflected as owned in the financial statements referred to in Section 1(y) above, in each case free and clear of any security interests, mortgages, liens, encumbrances, equities, claims and other defects, except such as do not materially and adversely affect the value of such property and do not materially interfere with the use made or proposed to be made of such property by the Company. The real property, improvements, equipment and personal property held under lease by the Company are held under valid and enforceable leases, with such exceptions as are not material and do not materially interfere with the use made or proposed to be made of such real property, improvements, equipment or personal property by the Company.

(dd) The Company has filed all necessary federal, state, local and foreign income and franchise tax returns in a timely manner and has paid all taxes required to be paid by it and, if due and payable, any similar assessment or related fine or penalty levied against it, except for any taxes, assessments, fines or penalties as may be being contested in good faith and by appropriate proceedings. The Company has made appropriate provisions in the applicable financial statements referred to in Section 1(y) above in respect of all federal, state, local and foreign income and franchise taxes for all current or prior periods as to which the tax liability of the Company has not been finally determined.

(ee) Except as described in the Time of Sale Prospectus and the Prospectus, the Company is insured with policies in such amounts and with such deductibles and covering such risks as are generally deemed adequate and customary for its business. All policies of insurance insuring the Company or its businesses, assets, employees, officers and directors are in full force and effect; and there are no claims by the Company under any such policy or instrument as to which any insurance company is denying liability or defending under a reservation of rights clause.

(ff) The Company has not taken and will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares.

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

(hh) The books, records and accounts of the Company accurately and fairly reflect in all material respects, in reasonable detail, the transactions in, and dispositions of, the assets of, and the results of operations of, the Company. The Company has established and maintains “disclosure controls and procedures” (as such term is defined in Rule 13a-15 under the Exchange Act), which (i) are designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms, (ii) are designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the Company’s management, including its principal executive officer and principal financial officer, as appropriate, to allow timely decisions regarding required disclosure and (iii) are sufficient to provide reasonable assurances with respect to the performance of the functions for which they were established. The auditors have not brought to the Company’s attention any material weakness in the Company’s internal control over financial reporting (whether or not remediated). Based on the most recent evaluation of the Company’s controls and procedures, the Company is not aware of (a) any significant deficiency in the design or operation of its internal controls which could adversely affect the Company’s ability to record, process, summarize and report financial data or, (b) any material weaknesses in its internal controls or (c) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal controls. To the Company’s knowledge, there has been no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(ii) Except as otherwise disclosed in the Time of Sale Prospectus and the Prospectus, there is no broker, finder or other party that is entitled to receive from the Company any brokerage or finder’s fee or other fee or commission as a result of any transactions contemplated by this Agreement.

(jj) There are no outstanding loans, advances (except normal advances for business expenses in the ordinary course of business) or guarantees or indebtedness by the Company to or for the benefit of any of the officers or directors of the Company, except as disclosed in the Time of Sale Prospectus and the Prospectus.

(kk) There is and has been no material failure on the part of the Company and, to the knowledge of the Company, any of the Company’s directors or officers, in their capacities as such, to comply with any provision of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith (the “ Sarbanes Oxley Act ”) that are applicable to the Company.

(ll) Except as disclosed in the Time of Sale Prospectus and the Prospectus, the Company (i) does not have any material lending relationship with any bank or lending affiliate of the Placement Agent and (ii) does not intend to use any of the proceeds from the sale of the Shares hereunder to repay any outstanding debt owed to any affiliate of the Placement Agent.

2. Fees. (a) For this assignment the Placement Agent will charge the Company a placement fee (the “ Placement Fee ”) of four percent (4%) of the aggregate price at which the Shares are sold by the Company. The Placement Fee shall be payable in immediately available funds on the Closing Date. At the Closing, the Company shall direct the Escrow Agent to wire to an account or accounts designated by the Placement Agent the Placement Fee out of the Escrow Funds.

(b) The right of the Placement Agent to receive the fees set forth in this Section 2 shall survive the termination of this Agreement in accordance with Section 7 hereof.

3. Conditions to the Placement Agent’s Obligations . The obligations of the Placement Agent are subject to the following conditions:

(a) Subsequent to the execution and delivery of this Agreement and prior to the Closing Date:

(i) there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible chan