Form of Underwriting Agreement

Medivation, Inc., a Delaware corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to you (collectively, the “Underwriters”) an aggregate of 8,700,000 shares (the “Firm Shares”) and, at the election of the Underwriters, up to 1,305,000 additional shares (the “Optional Shares”) of common stock of the Company, $0.01 par value per share (“Common Stock”). The Firm Shares and the Optional Shares which the Underwriters elect to purchase pursuant to Section 3 hereof are herein collectively called the “Shares.”

1. Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, each of the Underwriters that:

(a) A registration statement on Form SB-2 (File No. 333- ) (the “Initial Registration Statement”) in respect of the Shares has been filed with the Securities and Exchange Commission (the “Commission”); the Initial Registration Statement including any pre-effective amendments thereto and any post-effective amendments thereto, each in the form heretofore delivered to you and, excluding exhibits thereto, delivered to you for each of the other Underwriters, have been declared effective by the Commission in such form; other than a registration statement, if any, increasing the size of the offering (a “Rule 462(b) Registration Statement”), filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the “Act”), which became effective upon filing, no other document with respect to the Initial Registration Statement has heretofore been filed with the Commission; and no stop order suspending the effectiveness of the Initial Registration Statement, any post-effective amendment thereto or the Rule 462(b) Registration Statement, if any, has been issued and no proceeding for that purpose has been initiated or, to the Company’s knowledge, threatened by the Commission (any preliminary prospectus included in the Initial Registration Statement or filed with the Commission pursuant to Rule 424(a) of the rules and regulations of the Commission under the

Act is hereinafter called a “Preliminary Prospectus”); the various parts of the Initial Registration Statement and the Rule 462(b) Registration Statement, if any, including the information contained in the form of final prospectus filed with the Commission pursuant to Rule 424(b) under the Act in accordance with Section 5(a) hereof and deemed by virtue of Rule 430A under the Act to be part of the Initial Registration Statement at the time it was declared effective or the Rule 462(b) Registration Statement, if any, at the time it became effective, each as amended at the time such part of such Initial Registration Statement became effective, are hereinafter collectively called the “Registration Statement”; such final prospectus, in the form first filed pursuant to Rule 424(b) under the Act, is hereinafter called the “Prospectus”;

(b) No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, conformed in all material respects to the requirements of the Act and the rules and regulations of the Commission thereunder, and did not 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; provided, however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter through you expressly for use therein. The Company acknowledges that the statements set forth in the third, eighth, twelfth and thirteenth paragraphs under the heading “Underwriting” in the Prospectus constitute the only information relating to any Underwriter furnished in writing to the Company by any Underwriter expressly for use in the Registration Statement;

(c) The Registration Statement conforms, and the Prospectus and any further amendments or supplements to the Registration Statement or the Prospectus will conform, in all material respects to the requirements of the Act and the rules and regulations of the Commission thereunder and do not and will not, as of the applicable effective date as to the Registration Statement and any amendment thereto and as of the applicable filing date and the applicable Time of Delivery (as hereinafter defined) as to the Prospectus and any amendment or supplement thereto contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Preliminary Prospectus, the Prospectus or any supplement thereto, necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter through you expressly for use therein;

(d) There are no contracts or other documents required to be described in the Registration Statement or to be filed as exhibits to the Registration Statement by the Act or by the rules and regulations thereunder which have not been described in or filed as exhibits to the Registration Statement, as required; the contracts so described in the Prospectus to which the Company or any of its subsidiaries is a party have been duly authorized, executed and delivered by the Company or its subsidiaries, constitute valid and binding agreements of the Company or its subsidiaries and are enforceable against and by the Company or its subsidiaries in accordance

with their respective terms, and are in full force and effect on the date hereof; and, except as described in the Prospectus, neither the Company nor any of its subsidiaries, nor, to the best of the Company’s knowledge, any other party is in breach of or default under any of such contracts;

(e) Since the date of the latest audited financial statements included in the Prospectus neither the Company nor any of its subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth in the Prospectus; and, since the respective dates as of which information is given in the Registration Statement and the Prospectus, there has not been any change in the capital stock (other than issuances of Common Stock pursuant to Company stock option and stock purchase plans described in the Registration Statement and Prospectus) or long-term debt of the Company or any of its subsidiaries or any material adverse change, or any development involving a prospective material adverse change, in or affecting the business, assets, management, financial position, stockholders’ equity or results of operations of the Company and its subsidiaries taken as a whole, otherwise than as set forth or contemplated in the Prospectus;

(f) The Company and its subsidiaries have good and marketable title to all properties and assets described in the Prospectus as owned by it, in each case free and clear of all liens, charges, encumbrances or restrictions, except such as are described in the Prospectus or are not material to the business of the Company; any real property and buildings held under lease by the Company and its subsidiaries are held by them under valid, subsisting and enforceable leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries; the Company and its subsidiaries own or lease all such properties as are necessary to its operations as now conducted or as proposed to be conducted, except where the failure to so own or lease would not result in a material adverse change in or affecting the business, assets, management, financial position, stockholders’ equity or results of operations of the Company;

(g) Each of the Company and its subsidiaries has been duly incorporated and is validly existing as a corporation in good standing under the laws of its respective jurisdiction of organization, each with full power and authority (corporate and otherwise) to own its properties and conduct its business as described in the Prospectus, and each has been duly qualified as a foreign corporation for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require such qualification, or is subject to no material liability or disability by reason of the failure to be so qualified in any such jurisdiction;

(h) The Company has an authorized capitalization as set forth in the Prospectus, and all the issued shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and conform to the description of the Common Stock contained in the Prospectus; all of the issued shares of capital stock of each subsidiary of the Company (i) have been duly and validly authorized and issued, are fully paid and non-assessable and (ii) except as disclosed in the Prospectus, are owned directly by the Company, free and clear of all liens, encumbrances, equities or claims; except as disclosed in or contemplated by the Prospectus and the consolidated financial statements of the Company, and

the related notes thereto, included in the Prospectus, neither the Company nor any subsidiary has outstanding any options to purchase, or any preemptive rights or other rights to subscribe for or to purchase any securities or obligations convertible into, or any contracts or commitments to issue or sell, shares of its capital stock or any such options, rights, convertible securities or obligations; and the description of the Company’s stock option and stock purchase plans and the options or other rights granted and exercised thereunder set forth in the Prospectus accurately and fairly presents in all material respects the information required to be shown with respect to such plans, options and rights;

(i) The Shares to be issued and sold by the Company to the Underwriters hereunder have been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued and fully paid and non-assessable and will conform to the description of the Common Stock contained in the Prospectus; no preemptive rights or other rights to subscribe for or purchase exist with respect to the issuance and sale of the Shares by the Company pursuant to this Agreement; no stockholder of the Company has any right, which has not been waived, to require the Company to register the sale of any shares of capital stock owned by such stockholder under the Act in the public offering contemplated by this Agreement; and no further approval or authority of the stockholders or the Board of Directors of the Company will be required for the issuance and sale of the Shares to be sold by the Company as contemplated herein;

(j) The Company has full corporate power and authority to enter into this Agreement; and this Agreement has been duly authorized, executed and delivered by the Company, constitutes a valid and binding obligation of the Company and is enforceable against the Company in accordance with its terms;

(k) The issue and sale of the Shares by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions herein contemplated will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other material agreement or material instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject, nor will such action result in any violation of the provisions of the Certificate of Incorporation or By-laws of the Company or any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Shares or the consummation by the Company of the transactions contemplated by this Agreement, except the registration under the Act of the Shares and such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws or the bylaws and rules of the National Association of Securities Dealers, Inc. (“NASD”) in connection with the purchase and distribution of the Shares by the Underwriters;

(l) Neither the Company nor any of its subsidiaries is in violation of its Certificate of Incorporation or By-laws or in default in the performance or observance of any material obligation, agreement, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which it is a party or by which it or any of its properties may be bound;

(m) The statements set forth in the Prospectus under the caption “Description of Capital Stock,” insofar as they purport to constitute a summary of the terms of the Stock and under the caption “Underwriting,” insofar as they purport to describe the provisions of the laws and documents referred to therein, are accurate, complete and fair;

(n) There are no legal or governmental actions, suits or proceedings pending or, to the best of the Company’s knowledge, threatened to which the Company or any of its subsidiaries is or may be a party or of which property owned or leased by the Company or any of its subsidiaries is or may be the subject, or related to environmental or discrimination matters, which actions, suits or proceedings, could, individually or in the aggregate, prevent or adversely affect the transactions contemplated by this Agreement or result in a material adverse change in the present or future business, assets, management, financial position, stockholders’ equity or results of operations of the Company; no labor disturbance by the employees of the Company or any of its subsidiaries exists or, to the knowledge of the Company, is imminent that would reasonably be expected to affect materially and adversely such business, assets, management, financial position, stockholders’ equity or results of operations; and neither the Company nor any of its subsidiaries is a party or subject to the provisions of any material injunction, judgment, decree or order of any court, regulatory body, administrative agency or other governmental body, that could affect materially and adversely such business, assets, management, financial position, stockholders’ equity or results of operations;

(o) The Company and its subsidiaries possess all licenses, certificates, authorizations or permits issued by the appropriate governmental or regulatory agencies or authorities that are necessary to enable them to own, lease and operate their respective properties and to carry on their respective businesses as presently conducted except, where the failure to possess such licenses, certificates, authorization or permits would not reasonably be expected to affect materially and adversely such business, assets, management financial position, stockholders’ equity or results of operations, including without limitation all such certificates, authorities or permits required by the United States Food and Drug Administration (“FDA”) or any other federal, state or foreign agencies or bodies engaged in the regulation of pharmaceuticals and biohazardous materials, and has not received any notice of proceedings relating to the revocation or modification of any such certificate, authority or permit that, if determined adversely to the Company or its subsidiaries, would individually or in the aggregate have a material and adverse effect on the business, assets, management, financial position, stockholders’ equity or results of operations of the Company or its subsidiaries, and neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any such license, certificate, authority or permit which, singly or in the aggregate, would reasonably be expected to materially and adversely affect the business, assets, management, financial position, stockholders’ equity or results of operations of the Company and its subsidiaries;

(p) The Company and its subsidiaries (i) are in compliance in all material respects with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, including, without limitation, those relating to

occupational safety and health, the environment or hazardous or toxic substances or wastes, pollutants or contaminants, including, without limitation, those relating to the storage, handling or transportation of hazardous or toxic materials (collectively, “Environmental Laws”) and (ii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole. The Company, in its reasonable judgment, has concluded that any costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) would not, singly or in the aggregate, reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole;

(q) No Investigational New Drug (“IND”) application has been filed with the FDA by or on behalf of the Company or any of its subsidiaries. Each application to foreign regulatory bodies similar to an IND application to the FDA made by or on behalf of the Company or any of its subsidiaries, and related documents and information, has been filed, approved and maintained in compliance in all material respects with applicable statutes, rules, regulations, standards, guides or order administered or promulgated by such foreign regulatory body. All pre-clinical studies undertaken by or on behalf of the Company or any of its subsidiaries to support approval of products for commercialization have been conducted in compliance with all current Good Laboratory Practices and Good Clinical Practices applicable to such studies in all material respects. The Company’s ongoing Russain Phase II clinical study of Dimebon is being conducted in compliance with Good Clinical Practices in all material respects. No filing or submission to the FDA or any other regulatory body, that is intended to be the basis for any approval, contains any material omission or material false information. Except to the extent disclosed in the Registration Statements and the Prospectus, the Company and its subsidiaries have operated and currently are in compliance in all material respects with all applicable rules, regulations and policies of the FDA and comparable drug regulatory agencies outside of the United States.

(r) The ongoing Russian Phase II clinical study of Dimebon described in the Registration Statement and Prospectus is the only clinical study currently being conducted by or on behalf of the Company or any of its subsidiaries. To the best of the Company’s knowledge, all of the pre-clinical studies conducted by or on behalf of the Company or any of its subsidiaries and the Russian Phase II clinical study were and, if still pending, are being, conducted in accordance with experimental protocols, procedures and controls pursuant to accepted professional scientific standards. The descriptions of the results of the studies and trials contained in the Registration Statement and Prospectus are accurate and complete in all material respects and fairly present the data derived from such studies and trials. Except as described in the Registration Statement or Prospectus, the Company has no knowledge of any other studies or trials, the results of which are inconsistent with or otherwise call into question the results of the pre-clinical studies or clinical trials described in the Registration Statement and Prospectus. The Company or any of its subsidiaries have not received any notices or correspondence from the

FDA or any other governmental agency requiring the termination, suspension or modification of the ongoing Russian Phase II clinical study of Dimebon described in the Registration Statement and Prospectus.

(s) The Company and its subsidiaries have established and administer a compliance program applicable to the Company or its subsidiaries to assist the Company and its subsidiaries and their respective directors, officers, employees and consultants in complying with the regulatory guidelines (including, without limitation, those administered by the FDA or any other applicable foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) that are applicable to the Company.

(t) As of the date of this Agreement and the date of the Registration Statement, the Company satisfies the eligibility requirements for registrants for registration statement Form SB-2;

(u) Singer Lewak Greenbaum & Goldstein LLP, who have audited certain financial statements of the Company, are independent registered public accountants as required by the Act and the rules and regulations of the Commission thereunder;

(v) The consolidated financial statements and schedules of the Company, and the related notes thereto, included in the Registration Statement and the Prospectus present fairly in all material respects the financial position of the Company as of the respective dates of such financial statements and schedules, and the results of operations and cash flows of the Company for the respective periods covered thereby (subject, in the case of unaudited financial statements, to normal year-end adjustments); such statements, schedules and related notes have been prepared in accordance with generally accepted accounting principles applied on a consistent basis as certified by the independent registered public accountants named in paragraph (u) above; no other financial statements or schedules are required to be included in the Registration Statement; and the selected financial data set forth in the Prospectus under the captions “Summary Consolidated Financial Information” fairly present in all material respects the information set forth therein on the basis stated in the Registration Statement;

(w) Except as disclosed in the Prospectus, the Company and its subsidiaries own, or possess and/or have been granted valid and enforceable licenses for, all inventions, patents, patent applications, trademarks (registered or unregistered), trademark applications, tradenames, servicemarks, copyrights, manufacturing processes, formulae, trade secrets, know-how, and other intangible property and assets necessary to the conduct of its business as such business is described in the Prospectus (collectively, “Intellectual Property”). The expected expiration of any of the Company’s or its subsidiaries’ rights to the Intellectual Property would not, singly or in the aggregate, reasonably be expected to have a material adverse effect on the Company or its subsidiaries. The Company has no knowledge of any infringement or misappropriation by third parties of any of the Intellectual Property, nor is there any pending or, to the best knowledge of the Company, threatened action, suit, proceeding or claim by others challenging the Company’s or its subsidiaries’ rights of title or other interest in or to any Intellectual Property, and the Company does not know of any facts which would form a reasonable basis for any such claim. There is no pending or, to the best knowledge of the Company, threatened action, suit, proceeding or claim by others challenging the validity and

scope of any Intellectual Property, and the Company does not know of any facts which would form a reasonable basis for any such claim. There is no pending or, to the best knowledge of the Company, threatened action, suit, proceeding or claim by others that the Company or its subsidiaries or any of its products or processes or the Intellectual Property infringe or otherwise violate any patent, trademark, servicemark, copyright, trade secret or other proprietary right of others, and except as described in the Prospectus, the Company is unaware of any facts which would form a reasonable basis for any such claim. The Company is not aware of (i) any grounds for an interference proceeding before the United States Patent and Trademark Office in relation to any of the patents or patent applications currently owned by the Company, or (ii) any facts which would bar the grant of a patent from each of the patent applications described in the Prospectus. There is no pending or, to the best knowledge of the Company, threatened action, suit proceeding or claim by any current or former employee, consultant or agent of the Company or any of its subsidiaries seeking either ownership rights to any invention or other intellectual property right or compensation from the Company or any its subsidiaries for any invention or other intellectual property right made by such employee, consultant or agent in the course of his/her employment with the Company, its subsidiaries or otherwise. Except as described in the Prospectus, there is no act or omission by the Company, its subsidiaries or their agents or representatives of which the Company has knowledge that may render any patent or patent application within the Intellectual Property unpatentable, unenforceable or invalid. The Prospectus fairly and accurately describes in all material respects the Company’s and its subsidiaries’ rights with respect to the Intellectual Property;

(x) The Company and each of its subsidiaries have filed all necessary federal, state and foreign income and franchise tax returns, each of which has been true and correct in all material respects, and have paid all taxes shown as due thereon; and the Company has no knowledge of any material tax deficiency which has been or might be asserted or threatened against the Company or any of its subsidiaries;

(y) The Company is not an “investment company” or an “affiliated person” of, or “promoter” or “principal underwriter” for, an “investment company”, as such terms are defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”);

(z) Each of the Company and its subsidiaries maintains insurance of the types and in the amounts which it deems adequate for its business, including, but not limited to, insurance covering real and personal property owned or leased by the Company and its subsidiaries against theft, damage, destruction, acts of vandalism and all other risks customarily insured against, all of which insurance is in full force and effect;

(aa) Neither the Company nor any of its subsidiaries has at any time during the last five years (i) made any unlawful contribution to any candidate for foreign office, or failed to disclose fully any contribution in violation of law, or (ii) made any payment to any foreign, federal or state governmental officer or official, or other person charged with similar public or quasi-public duties, other than payments required or permitted by the laws of the United States, any foreign government or any respective jurisdiction thereof;

(bb) The Company has not taken and will not take, directly or indirectly through any of its directors, officers or controlling persons, any action which is designed to or

which has constituted or which might reasonably be 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;

(cc) The Common Stock of the Company has been registered pursuant to Section 12(g) of the Exchange Act and the Company is not required to take any further action for the inclusion of the Shares on the Nasdaq OTC Bulletin Board;

(dd) There are no business relationships or related-party transactions involving the Company or any subsidiary or any other person required to be described in the Prospectus which have not been described as required;

(ee) The Company maintains a system of 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 as applied 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;

(ff) The Company is aware of no reason that its quarterly report on Form 10-QSB for the quarter ended September 30, 2005 would not be accompanied by the certifications required to be filed or submitted by the Company’s chief executive officer and chief financial officer pursuant to the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated thereunder; and

(gg) The Company and its subsidiaries and any “employee benefit plan” (as defined under the Employee Retirement Income Security Act of 1974, as amended, and the regulations and published interpretations thereunder (collectively, “ERISA”)) established or maintained by the Company, its subsidiaries or their ERISA affiliates (as defined below) are in compliance in all material respects with ERISA. “ERISA Affiliate” means, with respect to the Company or a subsidiary, any member of any group of organizations described in Sections 414(b),(c),(m) or (o) of the Internal Revenue Code of 1986, as amended, and the regulations and published interpretations thereunder (the “Code”) of which the Company or such subsidiary is a member. No “reportable event” (as defined under ERISA) has occurred or is reasonably expected to occur with respect to any “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates. No “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates, if such “employee benefit plan” were terminated, would have any “amount of unfunded benefit liabilities” (as defined under ERISA). Neither the Company, its subsidiaries nor any of their ERISA Affiliates has incurred or reasonably expects to incur any liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any “employee benefit plan” or (ii) Sections 412, 4971, 4975 or 4980B of the Code. Each “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates that is intended to be qualified under Section 401(a) of the Code is so qualified and nothing has occurred, whether by action or failure to act, which would cause the loss of such qualification.

(a) On the basis of the representations, warranties and agreements of the Company contained herein, and subject to the terms and conditions of this Agreement, (i) the Company agrees to issue and sell the Firm Shares to the several Underwriters and (ii) each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at a purchase price per share of $ , the respective number of Firm Shares set forth opposite the name of such Underwriter in Schedule I hereto; and

(b) In the event and to the extent that the Underwriters shall exercise the election to purchase Optional Shares as provided below, (i) the Company agrees to issue and sell the Optional Shares to the several Underwriters and (ii) each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at the purchase price per share set forth in clause (a) of this Section 2, that portion of the number of Optional Shares as to which such election shall have been exercised as set forth opposite the name of such Underwriter in Schedule I hereto.

The Company hereby grants to the Underwriters the right to purchase at their election up to 1,305,000 Optional Shares at the purchase price per share set forth in the paragraph above, for the sole purpose of covering overallotments in the sale of the Firm Shares. Any such election to purchase Optional Shares may be exercised on one occasion by written notice from you to the Company, given within a period of 30 calendar days after the date of this Agreement and setting forth the aggregate number of Optional Shares to be purchased and the date on which such Optional Shares are to be delivered, as determined by you but in no event (i) earlier than the First Time of Delivery (as hereinafter defined) or, (ii) unless you and the Company otherwise agree in writing, earlier than two or later than three business days after the date of such notice.

3. Offering. Upon the authorization by you of the release of the Firm Shares, the several Underwriters propose to offer the Firm Shares for sale upon the terms and conditions set forth in the Prospectus.

4. Closing. Certificates in definitive form for the Shares to be purchased by each Underwriter hereunder, and in such denominations and registered in such names as Adams Harkness, Inc. may request upon at least forty-eight hours’ prior notice to the Company, shall be delivered by or on behalf of the Company to you for the account of such Underwriter, against payment by such Underwriter or on its behalf of the purchase price therefor by wire transfer of same day funds, all at the office of Adams Harkness, Inc., 99 High Street, Boston, Massachusetts 02110. The time and date of such delivery and payment shall be, with respect to the Firm Shares, 9:30 a.m., Boston time, on , 2005 or such other time and date as you and the Company may agree upon in writing, and, with respect to the Optional Shares, 9:30 a.m., Boston time, on the date specified by you in the written notice given by you of the Underwriters’ election to purchase such Optional Shares, or at such other time and date as you and the Company may agree upon in writing. Such time and date for delivery of the Firm Shares is herein called the “First Time of Delivery,” such time and date for delivery of the Optional Shares, if not the First Time of Delivery, is herein called the “Second Time of Delivery,” and each such time and date for delivery is herein called a “Time of Delivery.” Such certificates will

be made available for checking and packaging at least twenty-four hours prior to each Time of Delivery at such location as you may specify. If the Underwriters so elect, delivery of the Shares may be made by credit through full fast transfer to the accounts at the Depository Trust Company designated by Adams Harkness, Inc.

(a) To prepare the Prospectus in a form approved by you and to file such Prospectus pursuant to Rule 424(b) under the Act not later than Commission’s close of business on the second business day following the execution and delivery of this Agreement, or, if applicable, such earlier time as may be required by Rule 430A(a)(3) under the Act, to make no further amendment or any supplement to the Registration Statement or Prospectus which shall be reasonably disapproved by you promptly giving reasonable notice thereof; to advise you, promptly after it receives notice thereof, of the time when the Registration Statement, or any amendment thereto, has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed and to furnish you copies thereof; to advise you, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or Prospectus, of the suspension of the qualification of the Shares for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statement or Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or Prospectus or suspending any such qualification, to use promptly its best efforts to obtain its withdrawal;

(b) Promptly, from time to time, to take such action as you may reasonably request to qualify the Shares for offering and sale under the securities laws of such jurisdictions as you may request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of the Shares;

(c) To furnish the Underwriters with copies of the Prospectus in such quantities as you may from time to time reasonably request, and, if the delivery of a prospectus is required at any time prior to the expiration of nine months after the time of issuance of the Prospectus in connection with the offering or sale of the Shares and if at such time any events shall have occurred as a result of which the Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances under which they were made when such Prospectus is delivered, not misleading, or, if for any other reason it shall be necessary during such same period to amend or supplement the Prospectus in order to comply with the Act, to notify you and upon your request to prepare and furnish without charge to each Underwriter and to any dealer in securities as many copies as you may from time to time reasonably request of an amended Prospectus or a supplement to the Prospectus which will correct such statement or omission or effect such compliance, and in case any Underwriter is required by law to deliver a prospectus in connection with sales of any of the Shares at any time nine months or more after the time of issue of the Prospectus, upon your request but at the expense of such Underwriter, to prepare and deliver to such Underwriter as many copies as you may request of an amended or supplemented Prospectus complying with Section 10(a)(3) of the Act;

(d) To make generally available to its security holders as soon as practicable, but in any event not later than the forty-fifth (45th) day following the end of the full fiscal quarter first occurring after the first anniversary of the effective date of the Registration Statement (as defined in Rule 158(c)), an earning statement of the Company and its subsidiaries (which need not be audited) complying with Section 11(a) of the Act and the rules and regulations of the Commission thereunder (including, at the option of the Company, Rule 158);

(e) During the period beginning from the date hereof and continuing to and including the date 180 days after the date of the Prospectus (such period, the “Lock-Up Period”), not to offer, sell, contract to sell or otherwise dispose of any shares of Common Stock or any securities of the Company which are substantially similar, convertible or exchangeble into shares of Common Stock, without your prior written consent other than (i) the sale of the Shares to be sold by the Company hereunder and (ii) the Company’s issuance of shares and the award of options under its stock plans in amounts not in excess of the amount shown as available for grant in the Prospectus; provided further that you agree that you will not unreasonably withhold your consent in the event that, during the Lock-Up Period, the Company seeks to offer, sell or contract to sell any shares of Common Stock or any securities of the Company which are substantially similar, convertible or exchangeble into shares of Common Stock, the proceeds of which sale will be used solely for the purpose of acquiring or developing one or more new early-development stage biomedical technologies;

(f) Not to grant options to purchase shares of Common Stock which would become exercisable during the Lock-Up Period;

(g) Not to waive any terms of the lock-up agreements by and between the Company and each of David T. Hung, C. Patrick Machado, Dara BioSciences, Inc. and Selena Pharmaceuticals, Inc. entered into as of December 17, 2004, during the Lock-Up Period without your prior written consent;

(h) To furnish to its stockholders as soon as practicable after the end of each fiscal year an annual report (including a balance sheet and statements of income, stockholders’ equity and cash flow of the Company and its consolidated subsidiaries certified by independent public accountants) and to make available (within the meaning of Rule 158(b) under the Act) as soon as practicable after the end of each of the first three quarters of each fiscal year (beginning with the fiscal quarter ending after the effective date of the Registration Statement), consolidated summary financial information of the Company and its subsidiaries for such quarter in reasonable detail;

(i) During a period of five years from the effective date of the Registration Statement, to furnish to you upon your request copies of all reports or other communications (financial or other) furnished to stockholders generally, and deliver to you as soon as they are available, copies of any reports and financial statements furnished to or filed with the Commission, the Nasdaq OTC Bulletin Board or any securities exchange on which any class of securities of the Company is listed (such financial statements to be on a combined or

consolidated basis to the extent the accounts of the Company and its subsidiaries are combined or consolidated in reports furnished to its stockholders generally or to the Commission) (it being understood that filing on EDGAR shall be deemed to constitute delivery hereunder);

(j) To use the net proceeds acquired by it from the sale of the Shares in the manner specified in the Prospectus under the caption “Use of Proceeds” and in a manner such that the Company will not become an “investment company” as that term is defined in the Investment Company Act;

(k) Not to accelerate the vesting of any option issued under any stock option plan such that any such option may be exercised within 180 days from the date of the Prospectus;

(l) to use its best efforts to list for quotation the Shares on the Nasdaq OTC Bulletin Board;

(m) To file with the Commission such information on form 10-QSB or Form 10-KSB as may be required under the Act; and

(n) If the Company elects to rely upon rule 462(b), the Company shall file a Rule 462(b) Registration Statement with the commission in compliance with Rule 462(b) by 10:00 P.M., Washington, D.C. time, on the date of this Agreement, and the Company shall at the time of filing either pay to the Commission the filing fee for the Rule 462(b) Registration Statement or give irrevocable instructions for the payment of such fee pursuant to Rule 111(b) under the Act.

6. Expenses. The Company covenants and agrees with the several Underwriters that the Company will pay or cause to be paid the following: (i) the fees, disbursements and expenses of the Company’s counsel and accountants in connection with the registration of the Shares under the Act and all other expenses in connection with the preparation, printing and filing of the Registration Statement, any Preliminary Prospectus and the Prospectus and amendments and supplements thereto and the mailing and delivering of copies thereof to the Underwriters and dealers; (ii) the cost of reproducing any Agreement among Underwriters, this Agreement, the Blue Sky Memorandum and any other documents in connection with the offering, purchase, sale and delivery of the Shares; (iii) all expenses and filing fees in connection with the qualification of the Shares for offering and sale under state securities laws as provided in Section 5(b) hereof and securing any required review by the NASD of the terms of the sale of the Shares, including the fees and disbursements of counsel for the Underwriters in connection with such qualification and review and in connection with the Blue Sky survey; (iv) all fees and expenses in connection with listing the Shares with the Nasdaq OTC Bulletin Board; (v) the cost of preparing stock certificates; (vi) the cost and charges of any transfer agent or registrar; (vii) the fees for any travel expenses of the Company’s officers, employees or consultants in connection with attending or hosting meetings with prospective purchasers of the Shares; (viii) $200,000 for the fees, disbursements and expenses of the Underwriter’s counsel and all reasonable documented travel, marketing and other documented out of pocket expenses incurred by the Underwriters in connection with offering or sale of the Shares; (ix) all other costs and expenses incident to the performance of its obligations hereunder which are not otherwise specifically provided for in this Section. It is understood, however, that, except as provided in this Section, Section 8 and

Section 11 hereof, the Underwriters will pay all of their own costs and expenses, including the fees of their counsel, stock transfer taxes on resale of any of the Shares by them, and any advertising expenses connected with any offers they may make.

7. Conditions of Underwriters’ Obligations. The obligations of the Underwriters hereunder, as to the Shares to be delivered at each Time of Delivery, shall be subject, in their discretion, to the condition that all representations and warranties and other statements of the Company herein are, at and as of such Time of Delivery, true and correct, the condition that the Company shall have performed all of its respective obligations hereunder theretofore to be performed, and the following additional conditions:

(a) The Prospectus shall have been filed with the Commission pursuant to Rule 424(b) within the applicable time period prescribed for such filing by the rules and regulations under the Act and in accordance with Section 5(a) hereof, no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to your reasonable satisfaction;

(b) Wilson Sonsini Goodrich & Rosati, Professional Corporation, counsel to the Underwriters, shall have furnished to you such opinion or opinions, dated such Time of Delivery, with respect to this Agreement, the Registration Statement, the Prospectus, and other related matters as you may reasonably request;

(c) Latham & Watkins LLP, counsel to the Company, shall have furnished to you their written opinion, dated such Time of Delivery, in form and substance reasonably satisfactory to you, with respect to the matters set forth in Annex I hereto;

(d) Morrison & Foerster LLP, counsel to the Company, shall have furnished to you their written opinion, dated such Time of Delivery, in form and substance reasonably satisfactory to you, with respect to the matters set forth in Annex II hereto;

(e) On the date hereof and also at each Time of Delivery, Singer Lewak Greenbaum & Goldstein LLP, shall have furnished to you a letter or letters, dated the respective date of delivery thereof, in form and substance reasonably satisfactory to you, to the effect set forth in Annex III hereto;

(f) (i) Neither the Company nor any of its subsidiaries shall have sustained since the date of the latest audited financial statements included in the Prospectus any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus, and (ii) since the respective dates as of which information is given in the Prospectus, there shall not have been any change in the capital stock (other than issuances of Common Stock pursuant to Company stock option and stock purchase plans described in the Registration Statement and Prospectus) or long-term debt of the Company or any change, or any development involving a prospective change, in or affecting the business, assets, management, financial position, stockholders’ equity or results of

operations of the Company and its subsidiaries, otherwise than as set forth or contemplated in the Prospectus, the effect of which, in any such case described in clause (i) or (ii), is in the judgment of the Representative so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Shares being delivered at such Time of Delivery on the terms and in the manner contemplated in the Prospectus;

(g) On or after the date hereof there shall not have occurred any of the following: (i) additional material governmental restrictions, not in force and effect on the date hereof, shall have been imposed upon trading in securities generally or minimum or maximum prices shall have been generally established on the New York Stock Exchange or the Nasdaq National Market or in the over-the-counter market by the NASD, or trading in securities generally shall have been suspended on the New York Stock Exchange, the Nasdaq National Market or in the over the counter market by the NASD, or a general banking moratorium shall have been established by federal or New York authorities, (ii) a suspension or material limitation in trading in the Company’s securities on Nasdaq OTC Bulletin Board, (iii) an outbreak of major hostilities or other national or international calamity or any substantial change in political, financial or economic conditions shall have occurred or shall have accelerated or escalated to such an extent, as, in the judgment of the Representative, to affect materially and adversely the marketability of the Shares, or (iv) there shall be any action, suit or proceeding pending or threatened, or there shall have been any development or prospective development involving particularly the business or properties or securities of the Company or any of its subsidiaries or the transactions contemplated by this Agreement, which, in the judgment of the Representative, has materially and adversely affected the Company’s business or earnings and makes it impracticable or inadvisable to offer or sell the Shares;

(h) The Shares to be sold at such Time of Delivery shall have been accepted for quotation, subject to notice of issuance, on the Nasdaq OTC Bulletin Board;

(i) Each director and officer of the Company and the shareholders of the Company specified on Annex IV hereto shall have executed and delivered to you agreements in which such holder undertakes, for 180 days after the date of the Prospectus, subject to certain exceptions stated therein, not to offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale or otherwise dispose of any shares of Common Stock, or any securities convertible into or exchangeable for, or any rights to purchase or acquire, shares of Common Stock, without the prior written consent of Adams Harkness, Inc.;

(j) The Company shall have furnished or caused to be furnished to you at such Time of Delivery certificates of officers of the Company, in their capacities as such, satisfactory to you, as to the accuracy of the representations and warranties of the Company, herein at and as of such Time of Delivery, as to the performance by the Company, of all of its obligations hereunder to be performed at or prior to such Time of Delivery, and as to such other matters as you may reasonably request and the Company shall have furnished or caused to be furnished certificates as to the matters set forth in subsections (a), (f) and (g) of this Section, and as to such other matters as you may reasonably request.

(a) The Company will indemnify and hold harmless each Underwriter and each person, if any, who controls such Underwriter against any losses, claims, damages or liabilities, joint or several, to which such Underwriter or controlling person may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Registration Statement or the Prospectus, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Preliminary Prospectus, the Prospectus or any supplement thereto, necessary to make the statements therein, in light of the circumstances in which they were made, not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such action or claim as such expenses are incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in any Preliminary Prospectus, the Registration Statement or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by any Underwriter through Adams Harkness, Inc. expressly for use therein; and provided, further, that the Company and its subsidiaries shall not be liable to the Underwriters or any of their respective directors, officers, employees or controlling persons with respect to any such untrue statement or omission made in any Preliminary Prospectus existing as of the date hereof that is corrected in the Prospectus if it is judicially determined that (i) the person asserting any such loss, claim, damage, liability or action purchased Stock from the Underwriters in reliance upon the Preliminary Prospectus but was not delivered or sent a copy of the Prospectus, if required by law, at or prior to the written confirmation of the sale of such Stock to such person, unless such failure to deliver or send the Prospectus was a result of noncompliance by the Company with this Agreement and (ii) the Underwriters, and each such officer, director, employee and controlling person, if any, would not have incurred such loss, claim, damage, liability or action had the Prospectus been delivered or sent.

(b) Each Underwriter will indemnify and hold harmless the Company against any losses, claims, damages or liabilities to which the Company may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Registration Statement or the Prospectus, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Preliminary Prospectus, the Prospectus or any supplement thereto, necessary to make the statements therein, in light of the circumstances in which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged

omission was made in any Preliminary Prospectus, the Registration Statement or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by such Underwriter through you expressly for use therein; and will reimburse the Company for any legal or other expenses reasonably incurred by the Company in connection with investigating or defending any such action or claim as such expenses are incurred.

(c) Promptly after receipt by an indemnified party under subsection (a) or (b) above of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under such subsection, notify the indemnifying party in writing of the commencement thereof; but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to any indemnified party otherwise than under such subsection. In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such indemnified party under such subsection for any legal expenses of other counsel or any other expenses, in each case subsequently incurred by such indemnified party, in connection with the defense thereof other than reasonable costs of investigation. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings, be liable for (i) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Underwriters, its directors, officers and employees, and each person, if any, who controls any Underwriter within the meaning of the Securities Act, and (ii) the fees and expenses of more than one separate firm (in addition to any local counsel) for the Company, its officers and employees, its directors, and each person, if any, who controls the Company within the meaning of the Securities Act. No indemnifying party shall, without the written consent of the indemnified party, effect the settlement or compromise of, or consent to the entry of any judgment with respect to, any pending or threatened action or claim in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party. No indemnifying party shall be liable for any settlement of any action or claim effected without its written consent, which consent shall not be unreasonably withheld.

(d) If the indemnification provided for in this Section 8 is unavailable to or insufficient to hold harmless an indemnified party under subsection (a) or (b) above in respect of any losses, claims, damages or liabilities (or actions in respect thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (or actions in respect thereof) in such proportion as is appropriate to reflect the relative benefits received by the Company on the

one hand and the Underwriters on the other from the offering of the Shares. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law or if the indemnified party failed to give the notice required under subsection (c) above, then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities (or actions in respect thereof), as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Company, bear to the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or the Underwriters on the other and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this subsection (d) were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this subsection (d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions in respect thereof) referred to above in this subsection (d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this subsection (d), no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which such Underwriter 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 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this subsection (d) to contribute are several in proportion to their respective underwriting obligations and not joint.

(e) The obligations of the Company under this Section 8 shall be in addition to any liability which the Company may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Act; and the obligations of the Underwriter under this Section 8 shall be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company and to each person, if any, who controls the Company within the meaning of the Act.

(a) If any Underwriter shall default in its obligation to purchase the Shares which it has agreed to purchase hereunder at a Time of Delivery, you may in your discretion

arrange for you or another party or other parties to purchase such Shares on the terms contained herein. If within thirty-six (36) hours after such default by any Underwriter you do not arrange for the purchase of such Shares, then the Company shall be entitled to a further period of thirty-six (36) hours within which to procure another party or other parties satisfactory to you to purchase such Shares on such terms. In the event that, within the respective prescribed periods, you notify the Company that you have so arranged for the purchase of such Shares, or the Company notify you that it has so arranged for the purchase of such Shares, you or the Company shall have the right to postpone such Time of Delivery for a period of not more than seven (7) days, in order to effect whatever changes may thereby be made necessary in the Registration Statement or the Prospectus, or in any other documents or arrangements, and the Company agrees to file promptly any amendments to the Registration Statement or the Prospectus which in your opinion may thereby be made necessary. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section with like effect as if such person had originally been a party to this Agreement with respect to such Shares.

(b) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased does not exceed one-tenth of the aggregate number of all the Shares to be purchased at such Time of Delivery, then the Company shall have the right to require each non-defaulting Underwriter to purchase the number of Shares which such Underwriter agreed to purchase hereunder at such Time of Delivery and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the number of Shares which such Underwriter agreed to purchase hereunder) of the Shares of such defaulting Underwriter or Underwriters for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

(c) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased exceeds one-tenth of the aggregate number of all the Shares to be purchased at such Time of Delivery, or if the Company shall not exercise the right described in subsection (b) above to require non-defaulting Underwriters to purchase Shares of a defaulting Underwriter or Underwriters, then this Agreement (or, with respect to the Second Time of Delivery, the obligations of the Underwriters to purchase and of the Company to sell the Optional Shares) shall thereupon terminate, without liability on the part of any non-defaulting Underwriter or the Company, except for the expenses to be borne by the Company and the Underwriters as provided in Section 6 hereof and the indemnity and contribution agreements in Section 8 hereof, but nothing herein shall relieve a defaulting Underwriter from liability for its default.

10. Survival. The respective indemnities, agreements, representations, warranties and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of any Underwriter or any controlling person of any Underwriter, or the Company, or any officer or director or controlling person of the Company, and shall survive delivery of and payment for the Shares

11. Absence of Fiduciary Relationship. The Company acknowledges and agrees that:

(a) the Underwriters have been retained solely to act as underwriters in connection with the sale of the Shares and that no fiduciary, advisory or agency relationship between the Company and the Underwriters have been created in respect of any of the transactions contemplated by this Agreement, irrespective of whether the Underwriters have advised or are advising the Company on other matters;

(b) the price of the Shares set forth in this Agreement was established by the Company following discussions and arms-length negotiations with the Underwriters and the Company is capable of evaluating and understanding and understands and accepts the terms, risks and conditions of the transactions contemplated by this Agreement;

(c) it has been advised that the Underwriters and their affiliates are engaged in a broad range of transactions which may involve interests that differ from those of the Company and that the Underwriters have no obligation to disclose such interests and transactions to the Company by virtue of any fiduciary, advisory or agency relationship; and

(d) it waives, to the fullest extent permitted by law, any claims it may have against the Underwriters for breach of fiduciary duty or alleged breach of fiduciary duty and agrees that the Underwriters shall have no liability (whether direct or indirect) to the Company in respect of such a fiduciary duty claim or to any person asserting a fiduciary duty claim on behalf of or in right of the Company, including stockholders, employees or creditors of the Company.

12. Expenses of Termination. If this Agreement shall be terminated pursuant to Section 9 hereof, the Company shall then have no liability to any Underwriter except as provided in Section 6 and Section 8 hereof; but, if for any other reason this Agreement is terminated, or the transactions contemplated hereby shall not have been consummated due to any of the conditions set forth in Section 7 hereof not having been met, or the Shares are not delivered by or on behalf of the Company as provided herein, the Company will reimburse the Underwriters through you for all out-of-pocket expenses approved in writing by you, including fees and disbursements of counsel, reasonably incurred by the Underwriters in making preparations for the purchase, sale and delivery of the Shares not so delivered, but the Company shall have no further liability to any Underwriter in respect of the Shares not so delivered except as provided in Section 6 and Section 8 hereof.

13. Notice. In all dealings hereunder, you shall act on behalf of each of the Underwriters, and the parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter made or given by you jointly or by Adams Harkness, Inc. on behalf of you as the Underwriters.

All statements, requests, notices and agreements hereunder shall be in writing, and if to the Underwriters shall be delivered or sent by mail, telex or facsimile transmission to you as the Underwriters in care of Adams Harkness, Inc., 99 High Street, Boston, MA 02110, Attention: Equity Capital Markets; if to the Company shall be delivered or sent by mail, telex or facsimile

transmission to the address of the Company set forth in the Registration Statement, Attention: President; provided, however, that any notice to an Underwriter pursuant to Section 8(c) hereof shall be delivered or sent by mail, telex or facsimile transmission to such Underwriter at its address set forth in its Underwriter’s Questionnaire or telex constituting such Questionnaire, which address will be supplied to the Company by you on request. Any such statements, requests, notices or agreements shall take effect upon receipt thereof.

(a) This Agreement shall be binding upon, and inure solely to the benefit of, the Underwriters and the Company and, to the extent provided in Sections 8 and 10 hereof, the officers and directors of the Company and each person who controls the Company or any Underwriter, and their respective heirs, executors, administrators, successors and assigns, and no other person shall acquire or have any right under or by virtue of this Agreement. No purchaser of any of the Shares from any Underwriter shall be deemed a successor or assign by reason merely of such purchase.

(b) Time shall be of the essence of this Agreement. As used herein, the term “business day” shall mean any day when the Commission’s office in Washington, D.C. is open for business.

(d) This Agreement may be executed by any one or more of the parties hereto in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same instrument.

If the foregoing is in accordance with your understanding, please sign and return to us six counterparts hereof, and upon the acceptance hereof by you, on behalf of each of the Underwriters, this letter and such acceptance hereof shall constitute a binding agreement among each of the Underwriters and the Company. It is understood that your acceptance of this letter on behalf of each of the Underwriters is pursuant to the authority set forth in a form of Agreement among Underwriters, the form of which shall be submitted to the Company for examination, upon request, but without warranty on your part as to the authority of the signors thereof.


Very truly yours,

MEDIVATION, INC.

By:

Accepted as of the date hereof at Boston, Massachusetts

ADAMS HARKNESS, INC.

By:
		(Adams Harkness, Inc. on
		behalf of each of the Underwriters)


	Total Number of Firm Shares to be Purchased	Number of Optional Shares to be Purchased if Maximum Option Exercised
Adams Harkness, Inc.
_____________
_____________

TOTAL