] Shares NitroMed, Inc. Common Stock ($ 0.01 Par Value) EQUITY UNDERWRITING AGREEMENT

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Exhibit 1.1

[ ] Shares

NitroMed, Inc.

Common Stock

($ 0.01 Par Value)

, 2004

▇.▇. ▇▇▇▇▇▇ Securities Inc.
Pacific Growth Equities, LLC
Deutsche Bank Securities Inc.
Bear, ▇▇▇▇▇▇▇ & Co. Inc.
As Representatives of the
Several Underwriters

c/o ▇. ▇. ▇▇▇▇▇▇ Securities Inc.
▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

NitroMed, Inc., a Delaware corporation (the "Company"), proposes to sell to the several underwriters (the "Underwriters") named in Schedule I hereto for whom you are acting as representatives (the "Representatives") an aggregate of [ ] shares of the Company's Common Stock, $0.01 par value (the "Firm Shares"). The respective amounts of the Firm Shares to be so purchased by the several Underwriters are set forth opposite their names in Schedule I hereto. The Company also proposes to sell at the Underwriters' option an aggregate of up to [ ] additional shares of the Company's Common Stock (the "Option Shares") as set forth below.

As the Representatives, you have advised the Company (a) that you are authorized to enter into this Agreement on behalf of the several Underwriters, and (b) that the several Underwriters are willing, acting severally and not jointly, to purchase the numbers of Firm Shares set forth opposite their respective names in Schedule I, plus their pro rata portion of the Option Shares if you elect to exercise the over-allotment option in whole or in part for the accounts of the several Underwriters. The Firm Shares and the Option Shares (to the extent the aforementioned option is exercised) are herein collectively called the "Shares."

In consideration of the mutual agreements contained herein and of the interests of the parties in the transactions contemplated hereby, the parties hereto agree as follows:

1. REPRESENTATIONS AND WARRANTIES OF THE COMPANY.

The Company represents and warrants to each of the Underwriters as follows:

(a) A registration statement on Form S-1 (File No. 333-120280) with respect to the Shares has been prepared by the Company in conformity in all material respects with the requirements of the Securities Act of 1933, as amended (the "Act"), and the rules and regulations (the "Rules and Regulations") of the Securities and Exchange Commission (the "Commission") thereunder and has been filed with the Commission. Copies of such registration statement, including any amendments thereto, the preliminary prospectuses (meeting the requirements of the Rules and Regulations) contained therein and the exhibits and financial statements, as finally amended and revised, have heretofore been delivered by the Company to you. Such registration statement, together with any registration statement filed by the Company pursuant to Rule 462 (b) of the Act, is herein referred to as the "Registration Statement," which shall be deemed to include all information omitted

therefrom in reliance upon Rule 430A and contained in the Prospectus referred to below, has become effective under the Act and no post-effective amendment to the Registration Statement has been filed as of the date of this Agreement. "Prospectus" means the form of prospectus first filed with the Commission pursuant to Rule 424(b). Each preliminary prospectus included in the Registration Statement prior to the time it becomes effective is herein referred to as a "Preliminary Prospectus." Any reference to the Registration Statement, any Preliminary Prospectus or to the Prospectus or any amendment or supplement to any of the foregoing documents shall be deemed to refer to and include any supplements or amendments thereto, filed with the Commission after the date of filing of the Prospectus under Rules 424(b) or 430A and prior to he termination of the offering of the Shares by the Underwriters.

(b) The Company has been duly organized and is validly existing as a corporation in good standing under the laws of the State of Delaware, with corporate power and authority to own or lease its properties and conduct its business as described in the Registration Statement. Each of the subsidiaries of the Company as listed in Exhibit 21 to Item 16(a) of the Registration Statement (collectively, the "Subsidiaries") has been duly organized and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, with corporate power and authority to own or lease its properties and conduct its business as described in the Registration Statement. The Subsidiaries are the only subsidiaries, direct or indirect, of the Company. The Company and each of the Subsidiaries are duly qualified to transact business in all jurisdictions in which the conduct of their business requires such qualification, except for such jurisdictions where the failure to so qualify would not, individually or in the aggregate, result in any material adverse change in the earnings, business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company or its Subsidiaries, taken together as a whole (a "Material Adverse Change"). The outstanding shares of capital stock of each of the Subsidiaries have been duly authorized and validly issued, are fully paid and non-assessable and are owned by the Company or another Subsidiary free and clear of all liens, encumbrances and equities and claims; and no options, warrants or other rights to purchase, agreements or other obligations to issue or other rights to convert any obligations into shares of capital stock or ownership interests in the Subsidiaries are outstanding.

(c) The outstanding shares of Common Stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable; the Shares to be issued and sold by the Company have been duly authorized and when issued and paid for as contemplated herein will be validly issued, fully paid and non-assessable; and no preemptive rights of stockholders exist with respect to any of the Shares or the issue and sale thereof. Neither the filing of the Registration Statement nor the offering or sale of the Shares as contemplated by this Agreement gives rise to any rights, other than those which have been waived or satisfied, for or relating to the registration of any shares of Common Stock.

(d) The information set forth under the caption "Capitalization" in the Prospectus is fairly presented on a basis consistent with the Company's financial statements. All of the Shares conform to the description thereof contained in the Registration Statement. The form of certificates for the Shares conforms to the Delaware General Corporation Law.

(e) The Commission has not issued an order preventing or suspending the use of any Prospectus relating to the proposed offering of the Shares nor instituted proceedings for that purpose. The Registration Statement contains, and the Prospectus and any amendments or supplements thereto will contain, all statements which are required to be stated therein by, and will comply in all material respects with, the requirements of the Act and the Rules and Regulations. The Registration Statement and any amendment thereto do not contain, and will not contain, any untrue statement of a material fact and do not omit, and will not omit, to state any material fact required to be stated therein or necessary to make the statements therein not

misleading. The Prospectus and any amendments and supplements thereto do not contain, and will not contain, any untrue statement of material fact; and do not omit, and will not omit, to state any 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. Notwithstanding the foregoing, the Company makes no representations or warranties as to information contained in or omitted from 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 or on behalf of any Underwriter through the Representatives, specifically for use in the preparation thereof.

(f) Each material contract, agreement and license filed as an exhibit to the Registration Statement to which the Company or any of its Subsidiaries is bound is legal, valid, binding, enforceable and in full force and effect against the Company or such Subsidiary, and to the knowledge of the Company, each other party thereto, except to the extent such enforceability is subject to (i) laws of general application relating to bankruptcy, insolvency, moratorium and the relief of debtors and (ii) the availability of specific performance, injunctive relief and other equitable remedies. Neither the Company nor any of its Subsidiaries nor to the Company's knowledge any other party is in material breach or default with respect to any such contract, agreement and license, and, to the Company's knowledge, no event has occurred which with notice or lapse of time would constitute a material breach or default, or permit termination, modification, or acceleration, under any such contract, agreement or license. No party has repudiated any material provision of any such contract, agreement or license.

(g) The statistical and market-related data included in the Registration Statement and the Prospectus are based on or derived from sources which the Company reasonably and in good faith believes are reliable and accurate, and such data agree, in all material respects, with the sources from which they are derived.

(h) The consolidated financial statements of the Company and the Subsidiaries, together with related notes as set forth in the Registration Statement, present fairly the financial position, results of operations and cash flows of the Company and the consolidated Subsidiaries, at the indicated dates and for the indicated periods. Such financial statements and related notes have been prepared in accordance with generally accepted principles of accounting, consistently applied throughout the periods involved, except as disclosed therein, and all adjustments necessary for a fair presentation of results for such periods have been made. The summary financial and statistical data included in the Registration Statement present fairly, on the basis stated in the Registration Statement, the information shown therein and such data have been compiled on a basis consistent with the financial statements presented therein and the books and records of the Company. The pro forma financial statements and other pro forma financial information included in the Registration Statement and the Prospectus present fairly the information shown therein, have been prepared in accordance with the Commission's rules and guidelines with respect to pro forma financial statements, have been properly compiled on the pro forma bases described therein, and, in the opinion of the Company, the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions or circumstances referred to therein.

(i) Ernst & Young LLP, who have certified certain of the financial statements filed with the Commission as part of the Registration Statement, are independent public accountants as required by the Act and the Rules and Regulations.

(j) There is no action, suit, claim or proceeding pending or, to the knowledge of the Company, threatened against the Company or any of the Subsidiaries before any court or administrative agency or otherwise which if determined adversely to the Company or any of its

Subsidiaries might result in a Material Adverse Change or prevent the consummation of the transactions contemplated hereby, except as set forth in the Registration Statement.

(k) The Company and the Subsidiaries have good and marketable title in fee simple to all real property and good title to all personal property reflected in the consolidated financial statements hereinabove described or described in the Registration Statement, subject to no lien, mortgage, pledge, charge or encumbrance of any kind except (i) those reflected in such financial statements or described in the Registration Statement and (ii) liens and encumbrances for taxes not yet due and payable, and liens and encumbrances arising in the ordinary course of business or which are not material in amount. The Company and the Subsidiaries occupy their leased properties under valid and binding leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such properties by the Company or its Subsidiaries.

(l) The Company and the Subsidiaries have filed (or have duly requested extension of) all Federal, State, local and foreign tax returns which have been required to be filed and have paid all taxes indicated by such returns and all assessments received by them or any of them to the extent that such taxes have become due and payable, except for any such assessment that is currently being contested in good faith and which, if resolved unfavorably to the Company would not result in a Material Adverse Change. All tax liabilities have been adequately provided for in the financial statements of the Company, and the Company does not know of any actual or proposed additional material tax assessments.

(m) Since the respective dates as of which information is given in the Registration Statement, as it may be amended or supplemented, there has not been any Material Adverse Change or any development that would be reasonably expected to result in a Material Adverse Change, whether or not occurring in the ordinary course of business, and there has not been any material transaction entered into or any material transaction that is probable of being entered into by the Company or the Subsidiaries, other than transactions in the ordinary course of business and changes and transactions described in the Registration Statement, as it may be amended or supplemented. The Company and the Subsidiaries have no material contingent obligations which are not disclosed in the Company's financial statements which are included in the Registration Statement.

(n) Neither the Company nor any of the Subsidiaries is or with the giving of notice or lapse of time or both, will be, in violation of or in default under (i) its Certificate of Incorporation or By-Laws or (ii) under any agreement, lease, contract, indenture or other instrument or obligation to which it is a party or by which it, or any of its properties, is bound and, solely with respect to this clause (ii), which violation or default would result in a Material Adverse Change. The execution and delivery of this Agreement and the consummation of the transactions herein contemplated and the fulfillment of the terms hereof will not conflict with or result in a breach of any of the terms or provisions of, or constitute a default under, any material indenture, mortgage, deed of trust or other agreement or instrument to which the Company or any Subsidiary is a party or by which the Company or any Subsidiary or any of their respective properties is bound, or of the Certificate of Incorporation or By-Laws of the Company or any law, order, rule or regulation judgement, order, writ or decree applicable to the Company or any Subsidiary of any court or of any government, regulatory body or administrative agency or other governmental body having jurisdiction.

(o) The execution and delivery of, and the performance by the Company of its obligations under, this Agreement has been duly and validly authorized by all necessary corporate action on the part of the Company, and this Agreement has been duly executed and delivered by the Company.

(p) Each approval, consent, order, authorization, designation, declaration or filing by or with any regulatory, administrative or other governmental body necessary in connection with the execution and delivery by the Company of this Agreement and the consummation of the transactions herein contemplated (except such additional steps as may be required by the Commission or the National Association of Securities Dealers, Inc. (the "NASD") or such additional steps as may be necessary to qualify the Shares for public offering by the Underwriters under state securities or Blue Sky laws) has been obtained or made and is in full force and effect.

(q) The Company and the Subsidiaries each own or possess the right to use all patents, patent rights and patent applications (collectively, the "Company Patents"), trademarks, trade names, service marks, service names, copyrights, license rights, know-how (including trade secrets and other unpatented and unpatentable proprietary or confidential information, systems or procedures) and other intellectual property rights (collectively, the "Intellectual Property") necessary to carry on their business in all material respects as described in the Prospectus; neither the Company nor any of the Subsidiaries has infringed any Intellectual Property of any other person or entity. The Company has taken all reasonable steps necessary to secure interests in such Intellectual Property from its contractors. There are no outstanding options, licenses or agreements of any kind relating to the Intellectual Property of the Company that are required to be described in the Prospectus and are not described in all material respects. The Company is not a party to or bound by any options, licenses or agreements with respect to the Intellectual Property of any other person or entity that are required to be set forth in the Prospectus and are not described in all material respects. None of the technology employed by the Company has been obtained or is being used by the Company in violation of any contractual obligation binding on the Company or, to its knowledge, any of its officers, directors or employees or otherwise in violation of the rights of any persons; the Company has not received any written or oral communications alleging that the Company has violated, infringed or conflicted with, or, by conducting its business as set forth in the Prospectus, would violate, infringe or conflict with, any of the Intellectual Property of any other person or entity. The Company knows of no infringement by others of Intellectual Property owned by or licensed to the Company.

(r) All patent applications that resulted in Company Patents or pending applications that describe inventions necessary to conduct the business of the Company and its Subsidiaries in the manner described in the Prospectus (the "Company Patent Applications") have been duly and properly filed (have been accorded filing dates and serial numbers and assignments have been recorded for each listed inventory) or caused to be filed with the United States Patent and Trademark Office (the "PTO") and applicable foreign and international patent authorities. In connection with the filing of the Company Patent Applications, to the best knowledge of the Company, all printed publications and patent references relevant to the patentability of the inventions claimed in such applications has been disclosed to those patent offices so requiring. To the best knowledge of the Company, the Company has met its duty of candor and good faith to the PTO or similar foreign authority for the Company Patent Applications. No material misrepresentation have been made to the PTO or similar foreign authority by or in connection with the Company Patent Applications. The Company and its Subsidiaries are not aware or any facts material to a determination of patentability regarding the Company Patent Applications not called to the attention of the PTO or similar foreign authority. The Company has no knowledge of any facts which would preclude the Company from having clear title to the Company Patent Applications.

(s) Neither the Company, nor to the Company's knowledge, any of its affiliates, has taken or intends to take, directly or indirectly, any action designed to cause or result in, or which has constituted or which might reasonably be expected to constitute, the stabilization or manipulation of the price of the shares of Common Stock to facilitate the sale or resale of the Shares. The

Company acknowledges that the Underwriters may engage in passive market making transactions in the Shares on the Nasdaq National Market in accordance with Regulation M under the Securities Exchange Act of 1934, as amended (the "Exchange Act").

(t) Neither the Company nor any Subsidiary is and, after giving effect to the offering and sale of the Shares contemplated hereunder and the application of the net proceeds from such sale as described in the Prospectus, will be an "investment company" within the meaning of such term under the Investment Company Act of 1940, as amended (the "1940 Act") and the rules and regulations of the Commission thereunder.

(u) The Company and each of its Subsidiaries maintains a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management's general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles 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.

(v) The Company maintains "disclosure controls and procedures" (as defined in Rule 13a-15(e) under the Exchange Act) and the Company is otherwise in compliance in all material respects with all applicable effective provisions of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act of 2002 and the rules and regulations issued thereunder by the Commission.

(w) The Company and each of its Subsidiaries carry, or are covered by, insurance in such amounts and covering such risks as is customary for companies engaged in similar businesses.

(x) The Company and each Subsidiary is in compliance with all presently applicable provisions of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder ("ERISA"), except where such non-compliance would not result in a Material Adverse Change; no "reportable event" (as defined in ERISA) has occurred with respect to any "pension plan" (as defined in ERISA) to which the Company or any Subsidiary contributes or which the Company or any Subsidiary maintains; the Company and each Subsidiary has not incurred and does not expect to incur liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any "pension plan" or (ii) Sections 412 or 4971 of the Internal Revenue Code of 1986, as amended, including the regulations and published interpretations thereunder (the "Code"); and each "pension plan" for which the Company or any Subsidiary would have any liability that is intended to be qualified under Section 401(a) of the Code is so qualified in all material respects and nothing has occurred, whether by action or by failure to act, which would cause the loss of such qualification.

(y) To the Company's knowledge, there are no affiliations or associations between any member of the NASD and any of the Company's officers, directors or securityholders, except as set forth under the caption "Underwriting" in the Registration Statement.

(z) Except as described in the Prospectus, the Company and its Subsidiaries possess all certificates, authorizations, licenses and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses, including without limitation all such certificates, authorizations and permits required by the United States Food and Drug Administration (the "FDA") or any other federal, state or foreign agencies or bodies engaged in the regulation of pharmaceuticals or biohazardous materials, except where the failure to so possess such certificates, authorizations and permits, singly or in the aggregate, would not result in a Material Adverse Change; and, except as described in the Prospectus, neither the Company nor any of its Subsidiaries have received any notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, singly or in the aggregate, if

the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Change.

(aa) The studies, tests and preclinical and clinical trials conducted by or on behalf of the Company or any prior owner of the Company's Intellectual Property that are described in the Registration Statement and the Prospectus were and, if still pending, are being, conducted in all material respects in accordance with experimental protocols, procedures and controls pursuant to, where applicable, accepted professional scientific standards; the descriptions of the results of such studies, tests and trials contained in the Registration Statement and the Prospectus are accurate in all material respects; and the Company has not received any notices or correspondence from the FDA or any foreign, state or local governmental body exercising comparable authority requiring the termination, suspension or material modification of any studies, tests or preclinical or clinical trials conducted by or on behalf of the Company which termination, suspension or material modification would reasonably be expected to result in a Material Adverse Change.

2. PURCHASE, SALE AND DELIVERY OF THE FIRM SHARES.

(a) On the basis of the representations, warranties and covenants herein contained, and subject to the conditions herein set forth, the Company agrees to sell to the Underwriters and each Underwriter agrees, severally and not jointly, to purchase, at a price of [ ] per share, the number of Firm Shares set forth opposite the name of each Underwriter in Schedule I hereof, subject to adjustments in accordance with Section 9 hereof.

(b) Payment for the Firm Shares to be sold hereunder is to be made in Federal (same day) funds against delivery of certificates therefor to the Representatives for the several accounts of the Underwriters. Such payment and delivery are to be made through the facilities of The Depository Trust Company, New York, New York at 10:00 a.m., New York time, on the third business day after the date of this Agreement or at such other time and date not later than five business days thereafter as you and the Company shall agree upon, such time and date being herein referred to as the "Closing Date." (As used herein, "business day" means a day on which the New York Stock Exchange is open for trading and on which banks in New York are open for business and are not permitted by law or executive order to be closed.)

(c) In addition, on the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company hereby grants an option to the several Underwriters to purchase the Option Shares at the price per share as set forth in the first paragraph of this Section 2. The option granted hereby may be exercised in whole or in part by giving written notice (i) at any time before the Closing Date and (ii) only once thereafter within 30 days after the date of this Agreement, by you, as Representatives of the several Underwriters, to the Company setting forth the number of Option Shares as to which the several Underwriters are exercising the option and the time and date at which such certificates are to be delivered. The time and date at which certificates for Option Shares are to be delivered shall be determined by the Representatives but shall not be earlier than three nor later than 10 full business days after the exercise of such option, nor in any event prior to the Closing Date (such time and date being herein referred to as the "Option Closing Date"). If the date of exercise of the option is three or more days before the Closing Date, the notice of exercise shall set the Closing Date as the Option Closing Date. The number of Option Shares to be purchased by each Underwriter shall be in the same proportion to the total number of Option Shares being purchased as the number of Firm Shares being purchased by such Underwriter bears to the total number of Firm Shares, adjusted by you in such manner as to avoid fractional shares. The option with respect to the Option Shares granted hereunder may be exercised only to cover over-allotments in the sale of the Firm Shares by the Underwriters. You, as Representatives of the several Underwriters, may cancel such option at any time prior to its expiration by giving written notice of such cancellation to the Company. To

the extent, if any, that the option is exercised, payment for the Option Shares shall be made on the Option Closing Date in Federal (same day funds) through the facilities of The Depository Trust Company in New York, New York drawn to the order of the Company.

3. OFFERING BY THE UNDERWRITERS.

It is understood that the several Underwriters are to make a public offering of the Firm Shares as soon as the Representatives deem it advisable to do so. The Firm Shares are to be initially offered to the public at the initial public offering price set forth in the Prospectus. The Representatives may from time to time thereafter change the public offering price and other selling terms. To the extent, if at all, that any Option Shares are purchased pursuant to Section 2 hereof, the Underwriters will offer them to the public on the foregoing terms.

It is further understood that you will act as the Representatives for the Underwriters in the offering and sale of the Shares in accordance with a Master Agreement Among Underwriters entered into by you and the several other Underwriters.

4. COVENANTS OF THE COMPANY.

The Company covenants and agrees with the several Underwriters that:

(a) The Company will (A) use its best efforts to cause the Registration Statement to become effective or, if the procedure in Rule 430A of the Rules and Regulations is followed, to prepare and timely file with the Commission under Rule 424(b) of the Rules and Regulations a Prospectus in a form approved by the Representatives containing information previously omitted at the time of effectiveness of the Registration Statement in reliance on Rule 430A of the Rules and Regulations and (B) not file any amendment to the Registration Statement or supplement to the Prospectus of which the Representatives shall not previously have been advised and furnished with a copy or to which the Representatives shall have reasonably objected in writing or which is not in compliance with the Rules and Regulations.

(b) The Company will advise the Representatives promptly (A) when the Registration Statement or any post-effective amendment thereto shall have become effective, (B) of receipt of any comments from the Commission, (C) of any request of the Commission for amendment of the Registration Statement or for supplement to the Prospectus or for any additional information, and (D) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or the use of the Prospectus or of the institution of any proceedings for that purpose. The Company will use its best efforts to prevent the issuance of any such stop order preventing or suspending the use of the Prospectus and to obtain as soon as possible the lifting thereof, if issued.

(c) The Company will cooperate with the Representatives in endeavoring to qualify the Shares for sale under the securities laws of such jurisdictions as the Representatives may reasonably have designated in writing and will make such applications, file such documents, and furnish such information as may be reasonably required for that purpose, provided the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction where it is not now so qualified or required to file such a consent. The Company will, from time to time, prepare and file such statements, reports, and other documents, as are or may be required to continue such qualifications in effect for so long a period as the Representatives may reasonably request for distribution of the Shares.

(d) The Company will deliver to, or upon the order of, the Representatives, from time to time, as many copies of any Preliminary Prospectus as the Representatives may reasonably request. The Company will deliver to, or upon the order of, the Representatives during the period when delivery of a Prospectus is required under the Act, as many copies of the Prospectus in final form,

or as thereafter amended or supplemented, as the Representatives may reasonably request. The Company will deliver to the Representatives at or before the Closing Date, four signed copies of the Registration Statement and all amendments thereto including all exhibits filed therewith, and will deliver to the Representatives such number of copies of the Registration Statement (including such number of copies of the exhibits filed therewith that may reasonably be requested), and of all amendments thereto, as the Representatives may reasonably request.

(e) The Company will comply with the Act and the Rules and Regulations, and the Exchange Act, and the rules and regulations of the Commission thereunder, so as to permit the completion of the distribution of the Shares as contemplated in this Agreement and the Prospectus. If during the period in which a prospectus is required by law to be delivered by an Underwriter or dealer, any event shall occur as a result of which, in the judgment of the Company or in the reasonable opinion of the Underwriters, it becomes necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances existing at the time the Prospectus is delivered to a purchaser, not misleading, or, if it is necessary at any time to amend or supplement the Prospectus to comply with any law, the Company promptly will prepare and file with the Commission an appropriate amendment to the Registration Statement or supplement to the Prospectus so that the Prospectus as so amended or supplemented will not, in the light of the circumstances when it is so delivered, be misleading, or so that the Prospectus will comply with the law.

(f) The Company will make generally available to its security holders, as soon as it is practicable to do so, but in any event not later than 15 months after the effective date of the Registration Statement, an earning statement (which need not be audited) in reasonable detail, covering a period of at least 12 consecutive months beginning after the effective date of the Registration Statement, which earnings statement shall satisfy the requirements of Section 11(a) of the Act and Rule 158 of the Rules and Regulations and will advise you in writing when such statement has been so made available.

(g) Prior to the Closing Date, the Company will furnish to the Underwriters, as soon as they have been prepared by or are available to the Company, a copy of any unaudited interim financial statements of the Company for any period subsequent to the period covered by the most recent financial statements appearing in the Registration Statement and the Prospectus.

(h) No offering, sale, pledge, contract to sell, short sale, grant of an option or other disposition of any shares of Common Stock of the Company or other securities convertible into or exchangeable or exercisable for shares of Common Stock or derivative of Common Stock (or agreement for such) including any purchase, sale or grant of any right (including a put or call option) with respect to any security that includes, relates to or derives any sigificant part of its value from Common Stock, will be made for a period of 90 days after the date of this Agreement, directly or indirectly, by the Company otherwise than (i) pursuant to this Agreement, (ii) Common Stock issued by the Company either pursuant to the employee stock purchase plan of the Company or upon the exercise of options granted under existing stock option plans of the Company, provided the holders of Common Stock issued in such manner shall have executed a Lockup Agreement, (iii) options to purchase Common Stock granted under existing stock option plans of the Company, or (iv) with the prior written consent of ▇. ▇. ▇▇▇▇▇▇ Securities Inc. ("JPM"). The Company further agrees that, notwithstanding the foregoing, if (i) during the last 17 days of the 90-day restricted period described in the preceding sentence, the Company issues an earnings release or material news or a material event relating to the Company occurs, or (ii) prior to the expiration of such 90-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 90-day period, then the restrictions set forth in the preceding paragraph shall continue to apply until the expiration of the

18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

(i) The Company will use its best efforts to include the Shares on the Nasdaq National Market.

(j) The Company has caused its officers, directors and holders of more than five percent of the Company's outstanding Common Stock (except as listed in Schedule II hereto) to furnish to you, on or prior to the date of this agreement, a letter or letters, in form and substance satisfactory to the Underwriters, pursuant to which each such person shall agree not to offer, sell, sell short or otherwise dispose of any shares of Common Stock of the Company or other capital stock of the Company, or any other securities convertible, exchangeable or exercisable for Common Stock or derivative of shares of Common Stock owned by such person or request the registration for the offer or sale of any of the foregoing (or as to which such person has the right to direct the disposition of) for a period of 60 days after the date of this Agreement, directly or indirectly, except with the prior written consent of JPM ("Lockup Agreements").

(k) The Company shall apply the net proceeds of its sale of the Shares as set forth in the Prospectus and shall file such reports with the Commission with respect to the sale of the Shares and the application of the proceeds therefrom as may be required in accordance with Rule 463 under the Act.

(l) The Company shall not invest, or otherwise use the proceeds received by the Company from its sale of the Shares in such a manner as would require the Company or any of the Subsidiaries to register as an investment company under the 1940 Act.

(m) The Company will maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar for the Common Stock.

(n) The Company will not take, directly or indirectly, any action designed to cause or result in, or that has constituted or might reasonably be expected to constitute, the stabilization or manipulation of the price of any securities of the Company.

5. COSTS AND EXPENSES.

The Company will pay all costs, expenses and fees incident to the performance of the obligations of the Company under this Agreement, including, without limiting the generality of the foregoing, the following: accounting fees of the Company; the fees and disbursements of counsel for the Company; the cost of printing and delivering to, or as requested by, the Underwriters copies of the Registration Statement, Preliminary Prospectuses, the Prospectus, this Agreement, the Underwriters' Selling Memorandum, the Underwriters' Invitation Letter, the Listing Application, the Blue Sky Survey and any supplements or amendments thereto; the filing fees of the Commission; the filing fees and expenses (including legal fees and disbursements) incident to securing any required review by the NASD of the terms of the sale of the Shares; the Listing Fee of the Nasdaq National Market; and the expenses, including the fees and disbursements of counsel for the Underwriters, incurred in connection with the qualification of the Shares under State securities or Blue Sky laws. The Company shall not, however, be required to pay for any of the Underwriters expenses (other than those related to qualification under NASD regulation and State securities or Blue Sky laws) except that, if this Agreement shall not be consummated because the conditions in Section 6 hereof are not satisfied, or because this Agreement is terminated by the Representatives pursuant to Section 11 hereof, or by reason of any failure, refusal or inability on the part of the Company to perform any undertaking or satisfy any condition of this Agreement or to comply with any of the terms hereof on its part to be performed, unless such failure, refusal or inability is due primarily to the default or omission of any Underwriter, the Company shall reimburse the several Underwriters for reasonable out-of-pocket expenses, including fees and

disbursements of counsel, reasonably incurred in connection with investigating, marketing and proposing to market the Shares or in contemplation of performing their obligations hereunder; but the Company shall not in any event be liable to any of the several Underwriters for damages on account of loss of anticipated profits from the sale by them of the Shares.

6. CONDITIONS OF OBLIGATIONS OF THE UNDERWRITERS.

The several obligations of the Underwriters to purchase the Firm Shares on the Closing Date and the Option Shares, if any, on the Option Closing Date are subject to the accuracy, as of the Closing Date or the Option Closing Date, as the case may be, of the representations and warranties of the Company contained herein, and to the performance by the Company of its covenants and obligations hereunder and to the following additional conditions:

(a) The Registration Statement and all post-effective amendments thereto shall have become effective and any and all filings required by Rule 424 and Rule 430A of the Act shall have been made within the applicable time period prescribed by, and in compliance with, the Rules and Regulations, and any request of the Commission for additional information (to be included in the Registration Statement or otherwise) shall have been disclosed to the Representatives and complied with to their reasonable satisfaction. No stop order suspending the effectiveness of the Registration Statement, as amended from time to time, shall have been issued and no proceedings for that purpose shall have been taken or, to the knowledge of the Company, shall be contemplated or threatened by the Commission and no injunction, restraining order or order of any nature by a Federal or state court of competent jurisdiction shall have been issued as of the Closing Date which would prevent the issuance of the Shares.

(b) The Representatives shall have received on the Closing Date or the Option Closing Date, as the case may be, the corporate opinion of ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, counsel for the Company, dated the Closing Date or the Option Closing Date, as the case may be, addressed to the Underwriters (and stating that it may be relied upon by counsel to the Underwriters) to the effect that:

(i) The Company is a corporation duly organized, validly existing and in good standing under the laws of the State of Delaware, and has all requisite corporate power and authority to carry on its business and to own and lease its properties as such business and properties are described in the Prospectus. Each Subsidiary is a corporation duly organized, validly existing and in good standing under the laws of its jurisdiction of its incorporation. The Company and the Subsidiary are duly qualified to do business and are in good standing in the Commonwealth of Massachusetts.

(ii) The authorized capital stock of the Company on the date hereof consists of (A) 65,000,000 shares of Common Stock, $.01 par value per share, and (B) 5,000,000 shares of Preferred Stock, $.01 par value per share. The currently outstanding shares of Common Stock of the Company have been duly authorized and validly issued and are fully paid and nonassessable.

(iii) The certificates evidencing the Shares delivered to the Representatives for the several accounts for the Underwriters, assuming they are in the form filed with the Commission, are in due and proper form under the Delaware General Corporation Law statute, and when duly countersigned by the Company's transfer agent and registrar and delivered to the Representatives or upon their order against payment of the agreed consideration therefor in accordance with the provisions of this Agreement, the Shares to be sold pursuant to this Agreement will be duly authorized and validly issued, fully paid and non-assessable. The issuance of such Shares will not be subject to any preemptive or similar statutory rights under the Delaware General Corporation Law statute, the Company's Certificate of Incorporation or

By-Laws, or, to the knowledge of such counsel, similar contractual rights granted by the Company (except for such contractual rights as have been waived). To the knowledge of such counsel, except as described in the Registration Statement, there are no contracts, agreements or understandings between the Company and any person to file a registration statement under the Act with respect to any securities of the Company or to require the Company to include such securities with the Shares registered pursuant to the Registration Statement, except in each case for any such rights that have been waived.

(iv) The Registration Statement has been declared effective by the Commission under the Act and, to the knowledge of such counsel (A) no stop order suspending its effectiveness has been issued and (B) no proceedings for that purpose are pending before or threatened by the Commission.

(v) The statements under the captions "Risk Factors—If our third-party contract sales organization does not devote sufficient resources to out BiDil product, our ability to achieve near-term revenue could be harmed," "Risk Factors—The termination of our collaboration agreement with Merck, resulting from Merck's recent decision to withdraw its ▇▇▇-2 inhibitor, Vioxx, from worldwide markets, will result in the loss of anticipated milestone and royalty based revenue from the collaboration and may indicate that the development of nitric oxide-enhancing ▇▇▇-2 inhibitors is not viable," "Risk Factors—We currently depend on collaborative partners for a significant portion of our revenues and to develop, conduct clinical trials with, obtain regulatory approval for, and manufacture, market and sell some of our product candidates, and these collaborations may not be successful," "Risk Factors—We may incur significant costs and suffer management distraction and reputational damage from class action litigation and regulatory or government investigations and actions due to trading in our common stock," "Management's Discussion and Analysis of Financial Condition and Results of Operations—Overview (final paragraph only)," "Management's Discussion and Analysis of Financial Condition and Results of Operations—Financial Operations Overview—Nitric Oxide-Enhancing ▇▇▇-2 Inhibitors, Boston Scientific Collaboration and Merck Collaboration," "Business—BiDil Commercialization Plan," "Business—Corporate Collaborations," "Description of Capital Stock," "Shares Eligible for Future Sale" and "Underwriting" (only with respect to the description of this Agreement) in the Prospectus and Items 14 and 15 of Part II of the Registration Statement, insofar as such statements constitute summaries of matters of law or legal conclusions or summarize the terms of agreements or documents, are correct in all material respects.

(vi) Such counsel does not know any material legal or governmental proceedings pending or threatened against the Company before any Court, governmental or administrative body that are required by the Act or the Rules and Regulations to be described in the Registration Statement or in the Prospectus that are not so described.

(vii) The execution and delivery of this Agreement by the Company and the consummation by the Company of the transactions herein contemplated do not and will not (A) conflict with or constitute a breach of any of the terms or provisions of, or constitute a default under, the Certificate of Incorporation or By-Laws of the Company, as amended, or any indenture, loan agreement, mortgage, deed of trust or other agreement or instrument to which the Company or any of its Subsidiaries is a party or by which the Company or any of its Subsidiaries may be bound and that is filed as an exhibit to the Registration Statement and (B) violate any applicable United States federal or Massachusetts state statute, rule or regulation which in the experience of such counsel is normally applicable in transactions of the type contemplated by the Agreement or the Delaware General Corporation Law statute, or contravene any judgment, order or decree specifically naming the Company or its Subsidiary

of any governmental body, agency or court having jurisdiction over the Company or its Subsidiary of which such counsel is aware.

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

(ix) The execution and delivery of this Agreement by the Company and the consummation by the Company of the transactions contemplated hereby will not require any consent, approval, authorization or other order of, or qualification with, any court or governmental body or agency, except such as have been obtained under the Act and the Exchange Act and except such as may be required by the securities or Blue Sky laws of the various states or foreign jurisdictions or by the NASD, as to which such counsel need express no opinion.

(x) The Company is not and after giving effect to the offering and sale of the Shares and the application of the proceeds therefrom as described in the Prospectus, will not be an "investment company" as such term is defined in the 1940 Act.

(c) The Representatives shall have received on the Closing Date or the Option Closing Date, as the case may be, an intellectual property opinion of ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, counsel for the Company, dated the Closing Date or the Option Closing Date, as the case may be, addressed to the Underwriters (and stating that it may be relied upon by counsel to the Underwriters) to the effect that:

(i) To such counsel's knowledge, the Company and each of its Subsidiaries owns, possesses or has adequate rights to use the Intellectual Property reasonably necessary to carry on the business conducted by it as described in the Prospectus, except to the extent that the failure to own, possess or have adequate rights to use such Intellectual Property would not, individually or in the aggregate, reasonably be expected to have a material adverse effect on the Company or its Subsidiaries, taken together as a whole.

(ii) Other than as set forth or contemplated in the Registration Statement and the Prospectus, to such counsel's knowledge, none of the Company and its Subsidiaries have received any notice of infringement of or conflict with, and such counsel has no knowledge of any infringement of or conflict with, asserted rights of others with respect to the Company's Intellectual Property which would reasonably be expected to have a material adverse effect on the Company or its Subsidiaries, taken together as a whole.

(iii) Other than as set forth or contemplated in the Registration Statement and the Prospectus, to such counsel's knowledge, the discoveries, inventions, products or processes of the Company and its Subsidiaries referred to in the Registration Statement and the Prospectus do not infringe, interfere or conflict with any rights of any third party, or with any earlier discovery, invention, product or process that is the subject of a patent application filed by any third party which patent application has been published in the PTO or the World Intellectual Patent Office or is otherwise known to the Company except to the extent that any such infringement, individually or in the aggregate, would not reasonably be expected to have a material adverse effect on the Company or its Subsidiaries, taken together as a whole.

(iv) Other than as set forth or contemplated in the Registration Statement and the Prospectus, to such counsel's knowledge, no third party, including any academic or governmental organization, possesses rights to the Company Patents which, if exercised, would allow such third party to develop products competitive with those of the Company or could reasonably be expected to have a material adverse effect on the Company or its Subsidiaries, taken together as a whole.

(v) To the knowledge of such counsel, (A) the issued Company Patents are valid and enforceable and are entitled to a statutory presumption of validity and of ownership by the assignee, (B) there are no asserted claims of any persons relating to the scope or ownership of any of the Company Patents, (C) there are no liens which have been filed against any of the Company Patents, (D) there are no material defects of form in the preparation or filing of the Company's Patents, (E) the Company's patent applications are being diligently prosecuted, and (F) the Company and its Subsidiaries or, as appropriate, the Company's licensor, are listed on the records of the PTO or appropriate foreign patent offices as the sole assignee of record thereof.

(vi) To the knowledge of such counsel, all pertinent references were disclosed to the PTO or similar foreign authority during the prosecution of the Company Patents and no misrepresentation was made to, or material fact withheld from, the PTO or similar foreign authority during such prosecution.

(vii) To the knowledge of such counsel, the Company takes security measures adequate to assert trade secret protection in its non-patented technology.

(viii) The trademark BiDil has been registered in the PTO.

(ix) The statements under the captions "Risk Factors—Our patent protection for BiDil, which is a combination of two generic drugs, is limited and we may be subject to generic substitution or competition and resulting pricing pressure," "Risk Factors—If we are not able to obtain and enforce patent protection for our discoveries, our ability to develop and commercialize our product candidates will be harmed and we may not be able to operate our business profitably," "Risk Factors—If we become involved in patent litigation or other proceedings to enforce our patent rights, we could incur substantial costs and expenses, substantial liability for damages or be required to stop our product development and commercialization efforts," "Risk Factors—We in-license a significant portion of our principal proprietary technologies and if we fail to comply with our obligations under any of the related agreements, we could lose license rights that are necessary to developing BiDil and our other product candidates," "Business—Internal Development Programs," "Business—Proprietary Rights and Licensing," "Business—License and Royalty Agreements," and "Business—Trademarks, Trade Secrets and Other Proprietary Information" in the Prospectus, insofar as such statements constitute summaries of matters of law or legal conclusions or summarize the terms of agreements or documents, are correct in all material respects.

(d) In rendering such opinions ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP will rely only on the laws of the Commonwealth of Massachusetts, the Delaware General Corporation Law statute and Federal laws. In addition to the matters set forth above, such counsel shall state that, in connection with the preparation of the Registration Statement and the Prospectus, they have participated in conferences with officers and representatives of the Company, representatives of the Underwriters, counsel for the Underwriters and the independent accountants of the Company, at which conferences such counsel made inquiries of such persons and others and discussed the contents of the Registration Statement and the Prospectus. Such counsel shall further state that, while the limitations inherent in the independent verification of factual matters and the character of determinations involved in the registration process are such that they are not passing upon and do not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement or the Prospectus, subject to the foregoing and based on such participation, inquiries and discussions:

(i) The Registration Statement (except for the financial statements, including the notes thereto, and other financial or accounting data included therein, as to which such counsel need not express any view), at the time it became effective (but after giving effect to changes

incorporated pursuant to Rule 430A under the Act), and the Prospectus (except as aforesaid), as of the date it was filed with the Commission pursuant to Rules 424 and 430A under the Act, appear on their face to be appropriately responsive in all material respects to the requirements of the Act and the Rules and Regulations.

(ii) No facts have come to the attention of such counsel that cause them to believe that the Registration Statement, at the time it became effective (but after giving effect to changes incorporated pursuant to Rule 430A under the Act), contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading (except that such counsel need not express any view with respect to the financial statements, including the notes thereto, or any other financial or accounting data included therein).

(iii) No facts have come to the attention of such counsel that cause them to believe that the Prospectus, as of the date it was filed with the Commission pursuant to Rules 424 and 430A under the Act or of the Closing Date or the Option Closing Date, as the case may be, contained or contains any untrue statement of a material fact or omitted or omits to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that such counsel need not express any view with respect to the financial statements, including the notes thereto, or any other financial or accounting data included therein).

(iv) Such counsel is not aware of any contract or other document of a character required by the Securities Act and the applicable rules and regulations of the Commission thereunder to be filed as an exhibit to the Registration Statement that is not so filed.

(e) The Representatives shall have received from Kleinfeld, ▇▇▇▇▇▇ & ▇▇▇▇▇▇ LLP, counsel to the Company, an opinion dated the Closing Date or the Option Closing Date, as the case may be, in its capacity as special regulatory counsel to the Company, dated such date, to the effect that:

(i) Such counsel is familiar with the United States Federal Food, Drug, and Cosmetic Act (the "FFDC Act") and related government regulatory matters as applied generally to drugs of the nature under development and clinical testing by the Company and has reviewed the portions of the Registration Statement and the Prospectus under the captions ["Risk Factors—We are heavily dependent on obtaining regulatory approval for and successfully commercializing BiDil, our most advanced drug candidate," "Risk Factors—If our clinical trials for BiDil and any other product candidates we advance into clinical testing are not successful, we may not be able to successfully develop and commercialize our products," "Risk Factors—If we and our partners do not obtain and maintain the regulatory approvals required to market and sell BiDil and our other products under development, then our business will be unsuccessful and the market price of our stock will substantially decline," "Risk Factors—If we, our third-party manufacturers or our service providers fail to comply with applicable laws and regulations, we or they could be subject to enforcement actions, which could affect or ability to market and sell our products and harm our reputation," "Business—BiDil Treatment for Heart Failure in African Americans," and "Business—Regulatory Matters" (collectively, the "Regulatory Portion").

(ii) In such counsel's opinion, insofar as the statements in the Regulatory Portion constitute a summary of matters of law or regulatory requirements referred to therein, the Regulatory Portion fairly summarizes in all material respects the information called for with respect to such matters.

In addition to the matters set forth above, such opinion of Kleinfeld, ▇▇▇▇▇▇ and ▇▇▇▇▇▇ LLP shall also include a statement to the effect that in connection with their review of the Registration

Statement and the Prospectus, they have participated in conferences with officers, representatives and counsel of the Company, at which conferences they made inquiries of such persons and others and discussed the contents of the Registration Statement and the Prospectus. Such counsel shall further state that, while the limitations inherent in the independent verification of factual matters and the character of determinations involved in the registration process are such that they are not passing upon and do not assume any responsibility for the accuracy, completeness or fairness of factual statements contained in the Registration Statement or the Prospectus, subject to the foregoing and based on such participation, inquiries and discussions: nothing has come to the attention of such counsel which leads them to believe that (i) the Regulatory Portion of the Registration Statement at the time the Registration Statement became effective under the Act and as of the Closing Date or the Option Closing Date, as the case may be, contained or contains any untrue statement of a material fact or omitted or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading and (ii) the Regulatory Portion of the Prospectus, or any supplement thereto, on the date it was filed pursuant to the Rules and Regulations and as of the Closing Date or the Option Closing Date, as the case may be, contained or contains any untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(f) The Representatives shall have received from Ropes & ▇▇▇▇ LLP, counsel for the Underwriters, an opinion dated the Closing Date or the Option Closing Date, as the case may be, substantially to the effect specified in subparagraphs (iv) and (viii) of Paragraph (b) of this Section 6, that the shares of Common Stock, including the Option Shares, if any, to be sold by the Company pursuant to this Agreement have been duly authorized and will be validly issued, fully paid and non-assessable when issued and paid for as contemplated by this Agreement, and that the Company is a duly organized and validly existing corporation under the laws of the State of Delaware. In rendering such opinion Ropes & ▇▇▇▇ LLP will rely only on the laws of the Commonwealth of Massachusetts, the Delaware General Corporation Law statute and Federal laws. In addition to the matters set forth above, such opinion shall also include a statement to the effect that nothing has come to the attention of such counsel which leads them to believe that (i) the Registration Statement, or any amendment thereto, as of the time it became effective under the Act (including the information deemed to be a part of the Registration Statement at the time it became effective pursuant to Rule 430A under the Act) as of the Closing Date or the Option Closing Date, as the case may be, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading, and (ii) the Prospectus, or any supplement thereto, on the date it was filed pursuant to the Rules and Regulations and as of the Closing Date or the Option Closing Date, as the case may be, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact, necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that such counsel need express no view as to financial statements, schedules and statistical information therein). With respect to such statement, Ropes & ▇▇▇▇ LLP may state that their belief is based upon the procedures set forth therein, but is without independent check and verification.

(g) The Representatives shall have received at or prior to the Closing Date from Ropes & ▇▇▇▇ LLP a memorandum or summary, in form and substance satisfactory to the Representatives, with respect to the qualification for offering and sale by the Underwriters of the Shares under the State securities or Blue Sky laws of such jurisdictions as the Representatives may reasonably have designated to the Company.

(h) You shall have received, on each of the date hereof, the Closing Date and, if applicable, the Option Closing Date, a letter dated the date hereof, the Closing Date or the Option Closing

Date, as the case may be, in form and substance satisfactory to you, of Ernst & Young LLP confirming that they are independent public accountants within the meaning of the Act and the applicable published Rules and Regulations thereunder and stating that in their opinion the financial statements and schedules examined by them and included in the Registration Statement comply in form in all material respects with the applicable accounting requirements of the Act and the related published Rules and Regulations; and containing such other statements and information as is ordinarily included in accountants' "comfort letters" to Underwriters with respect to the financial statements and certain financial and statistical information contained in the Registration Statement and Prospectus.

(i) The Representatives shall have received on the Closing Date and, if applicable, the Option Closing Date, as the case may be, a certificate or certificates of the Chief Executive Officer and the Chief Financial Officer of the Company to the effect that, as of the Closing Date or the Option Closing Date, as the case may be, each of them severally represents as follows:

(i) The Registration Statement has become effective under the Act and no stop order suspending the effectiveness of the Registration Statement has been issued, and no proceedings for such purpose have been taken or are, to his knowledge, contemplated or threatened by the Commission;

(ii) The representations and warranties of the Company contained in Section 1 hereof are true and correct as of the Closing Date or the Option Closing Date, as the case may be;

(iii) All filings required to have been made pursuant to Rules 424 or 430A under the Act have been made as and when required by such rules;

(iv) He has carefully examined the Registration Statement and the Prospectus and, in his or her opinion, as of the effective date of the Registration Statement, the Registration Statement and Prospectus did not include any untrue statement of a material fact and did not omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading, and since the effective date of the Registration Statement, no event has occurred which should have been set forth in a supplement to or an amendment of the Prospectus which has not been so set forth in such supplement or amendment; and

(v) Since the respective dates as of which information is given in the Registration Statement and Prospectus, there has not been any Material Adverse Change or any development that would be expected to result in a Material Adverse Change, whether or not arising in the ordinary course of business.

(j) The Company shall have furnished to the Representatives such further certificates and documents confirming the representations and warranties, covenants and conditions contained herein and related matters as the Representatives may reasonably have requested.

(k) The Firm Shares and Option Shares, if any, have been approved for designation upon notice of issuance on the Nasdaq National Market.

(l) The Lockup Agreements described in Section 4 (j) are in full force and effect.

The opinions and certificates mentioned in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in all material respects reasonably satisfactory to the Representatives and to Ropes & ▇▇▇▇ LLP, counsel for the Underwriters.

If any of the conditions hereinabove provided for in this Section 6 shall not have been fulfilled when and as required by this Agreement to be fulfilled, the obligations of the Underwriters hereunder may be terminated by the Representatives by notifying the Company of such

termination in writing or by telegram at or prior to the Closing Date or the Option Closing Date, as the case may be.

In such event, the Company and the Underwriters shall not be under any obligation to each other (except to the extent provided in Sections 5 and 8 hereof).

7. CONDITIONS OF THE OBLIGATIONS OF THE COMPANY.

The obligations of the Company to sell and deliver the portion of the Shares required to be delivered as and when specified in this Agreement are subject to the conditions that at the Closing Date or the Option Closing Date, as the case may be, no stop order suspending the effectiveness of the Registration Statement shall have been issued and in effect or proceedings therefor initiated or threatened.

8. INDEMNIFICATION.

(a) The Company agrees:

(1) to indemnify and hold harmless each Underwriter and each person, if any, who controls or is alleged to control any Underwriter within the meaning of either Section 15 of the Act or Section 20 of the Exchange Act, against any losses, claims, damages or liabilities to which such Underwriter or any such controlling person may become subject under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, any Preliminary Prospectus, the Prospectus or any amendment or supplement thereto, (ii) the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances under which they were made or (iii) any act or failure to act, or any alleged act or failure to act by any Underwriter in connection with, or relating in any manner to, the Shares or the offering contemplated hereby, and which is included as part of or referred to in any loss, claim, damage, liability or action arising out of or based upon matters covered by clause (i) or (ii) above (provided, that the Company shall not be liable under this clause (iii) to the extent that it is determined in a final judgment by a court of competent jurisdiction that such loss, claim, damage, liability or action resulted directly from any such acts or failures to act undertaken or omitted to be taken by such Underwriter through its gross negligence or willful misconduct); provided, however, that the Company will not be liable in any such case to the extent (A) that any such losses, claims, damages or liabilities of the Underwriter or controlling person results from an untrue statement of a material fact contained in, or the omission of a material fact from, the Preliminary Prospectus that was corrected in the Prospectus or any amendment or supplement thereto, if such Underwriter sold Shares to the person alleging such loss, claim, damage or liability without sending or giving, at or prior to the written confirmation of the sale of such Shares, a copy of the Prospectus or any amendment or supplement thereto, but only if the Company has previously furnished copies of the Prospectus or any such amendment or supplement to the Underwriter, or (B) 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 the Registration Statement, any Preliminary Prospectus, the Prospectus, or such amendment or supplement, in reliance upon and in conformity with written information furnished to the Company by or through the Representatives specifically for use in the preparation thereof; and

(2) except as otherwise provided in Section 8(a)(1), to reimburse each Underwriter and each such controlling person upon demand for any legal or other out-of-pocket expenses reasonably incurred by such Underwriter or such controlling person in connection with

investigating or defending any such loss, claim, damage or liability, action or proceeding or in responding to a subpoena or governmental inquiry related to the offering of the Shares, whether or not such Underwriter or controlling person is a party to any action or proceeding. In the event that it is finally judicially determined that the Underwriters were not entitled to receive payments for legal and other expenses pursuant to this subparagraph, the Underwriters will promptly return all sums that had been advanced pursuant hereto.

(b) Each Underwriter severally and not jointly will indemnify and hold harmless the Company, each of its directors, each of its officers who have signed the Registration Statement, and each person, if any, who controls the Company within the meaning of the Act, against any losses, claims, damages or liabilities to which the Company or any such director, officer, or controlling person may become subject under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, any Preliminary Prospectus, the Prospectus or any amendment or supplement thereto, or (ii) the omission or the alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances under which they were made; and will reimburse any legal or other expenses reasonably incurred by the Company or any such director, officer, or controlling person in connection with investigating or defending any such loss, claim, damage, liability, action or proceeding; provided, however, that each Underwriter will be liable in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission has been made in the Registration Statement, any Preliminary Prospectus, the Prospectus or such amendment or supplement, in reliance upon and in conformity with written information furnished to the Company by or through the Representatives specifically for use in the preparation thereof. This indemnity agreement will be in addition to any liability which such Underwriter may otherwise have.

(c) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to this Section 8, such person (the "indemnified party") shall promptly notify the person against whom such indemnity may be sought (the "indemnifying party") in writing. No indemnification provided for in Section 8(a) or (b) shall be available to any party who shall fail to give notice as provided in this Section 8(c) if the party to whom notice was not given was unaware of the proceeding to which such notice would have related and was materially prejudiced by the failure to give such notice, but the failure to give such notice shall not relieve the indemnifying party or parties from any liability which it or they may have to the indemnified party for contribution or otherwise than on account of the provisions of Section 8(a) or (b). In case any such proceeding 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 reasonably satisfactory to such indemnified party and shall pay as incurred the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel at its own expense. Notwithstanding the foregoing, the indemnifying party shall pay as incurred (or within 30 days of presentation) the fees and expenses of the counsel retained by the indemnified party in the event (i) the indemnifying party and the indemnified party shall have mutually agreed to the retention of such counsel, (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them or (iii) the indemnifying party shall have failed to assume the defense and employ counsel acceptable to the indemnified party within a reasonable period of time after notice of

commencement of the action. It is understood that the indemnifying party shall not, in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the reasonable fees and expenses of more than one separate firm for all such indemnified parties. Such firm shall be designated in writing by the Representatives in the case of parties indemnified pursuant to Section 8(a) and by the Company in the case of parties indemnified pursuant to Section 8(b). The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. In addition, the indemnifying party will not, without the prior written consent of the indemnified party, settle or compromise or consent to the entry of any judgment in any pending or threatened claim, action or proceeding of which indemnification may be sought hereunder (whether or not any indemnified party is an actual or potential party to such claim, action or proceeding) unless such settlement, compromise or consent includes an unconditional release of each indemnified party from all liability arising out of such claim, action or proceeding.

(d) To the extent the indemnification provided for in this Section 8 is unavailable to or insufficient to hold harmless an indemnified party under Section 8(a) or (b) above in respect of any losses, claims, damages or liabilities (or actions or proceedings 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 or proceedings 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 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 or proceedings 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 untrue 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 Section 8(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 Section 8(d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions or proceedings in respect thereof) referred to above in this Section 8(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), (i) no Underwriter shall be required to contribute any amount in excess of the underwriting discounts and commissions applicable to the Shares purchased by such Underwriter and (ii) 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 Section 8(d) to contribute are several in proportion to their respective underwriting obligations and not joint.

(e) In any proceeding relating to the Registration Statement, any Preliminary Prospectus, the Prospectus or any supplement or amendment thereto, each party against whom contribution may be sought under this Section 8 hereby consents to the jurisdiction of any court having jurisdiction over any other contributing party, agrees that process issuing from such court may be served upon it by any other contributing party and consents to the service of such process and agrees that any other contributing party may join it as an additional defendant in any such proceeding in which such other contributing party is a party.

(f) Any losses, claims, damages, liabilities or expenses for which an indemnified party is entitled to indemnification or contribution under this Section 8 shall be paid by the indemnifying party to the indemnified party as such losses, claims, damages, liabilities or expenses are incurred. The indemnity and contribution agreements contained in this Section 8 and the representations and warranties of the Company set forth in this Agreement shall remain operative and in full force and effect, regardless of (i) any investigation made by or on behalf of any Underwriter or any person controlling any Underwriter, the Company, its directors or officers or any persons controlling the Company, (ii) acceptance of any Shares and payment therefor hereunder, and (iii) any termination of this Agreement. A successor to any Underwriter, or any person controlling any Underwriter, or to the Company, its directors or officers, or any person controlling the Company, shall be entitled to the benefits of the indemnity, contribution and reimbursement agreements contained in this Section 8.

9. DEFAULT BY UNDERWRITERS.

If on the Closing Date or the Option Closing Date, as the case may be, any Underwriter shall fail to purchase and pay for the portion of the Shares which such Underwriter has agreed to purchase and pay for on such date (otherwise than by reason of any default on the part of the Company), you, as Representatives of the Underwriters, shall use your reasonable efforts to procure within 36 hours thereafter one or more of the other Underwriters, or any others, to purchase from the Company such amounts as may be agreed upon and upon the terms set forth herein, the Shares which the defaulting Underwriter or Underwriters failed to purchase. If during such 36 hours you, as such Representatives, shall not have procured such other Underwriters, or any others, to purchase the Shares agreed to be purchased by the defaulting Underwriter or Underwriters, then (a) if the aggregate number of shares with respect to which such default shall occur does not exceed 10% of the Shares to be purchased on the Closing Date or the Option Closing date, as the case may be, the other Underwriters shall be obligated, severally, in proportion to the respective numbers of Shares which they are obligated to purchase hereunder, to purchase the Shares which such defaulting Underwriter or Underwriters failed to purchase, or (b) if the aggregate number of shares of Shares with respect to which such default shall occur exceeds 10% of the Shares to be purchased on the Closing Date or the Option Closing Date, as the case may be, the Company or you as the Representatives of the Underwriters will have the right, by written notice given within the next 36-hour period to the parties to this Agreement, to terminate this Agreement without liability on the part of the non-defaulting Underwriters or of the Company except to the extent provided in Sections 5 and 8 hereof. In the event of a default by any Underwriter or Underwriters, as set forth in this Section 9, the Closing Date or Option Closing Date, as the case may be, may be postponed for such period, not exceeding seven days, as you, as Representatives, may determine in order that the required changes in the Registration Statement or in the Prospectus or in any other documents or arrangements may be effected. The term "Underwriter" includes any person substituted for a defaulting Underwriter. Any action taken under this Section 9 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

10. NOTICES.

All communications hereunder shall be in writing and, except as otherwise provided herein, will be mailed, delivered, telecopied or telegraphed and confirmed as follows: if to the Underwriters, to ▇.▇. ▇▇▇▇▇▇ Securities Inc., ▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: ▇▇▇▇▇▇▇ ▇▇▇▇▇ and Ropes & ▇▇▇▇ LLP, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attention: ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇, Esq.; if to the Company, to Nitromed, Inc., ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attention Chief Executive Officer, with a copy to ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, ▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attention: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇.

11. TERMINATION.

This Agreement may be terminated by the Representatives by notice to the Company (a) at any time prior to the Closing Date or any Option Closing Date (if different from the Closing Date and then only as to Option Shares) if any of the following has occurred: (i) since the respective dates as of which information is given in the Registration Statement and the Prospectus, any material adverse change or any development involving a prospective material adverse change in or affecting the earnings, business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company and its Subsidiaries taken as a whole, whether or not arising in the ordinary course of business, (ii) any outbreak or escalation of hostilities or declaration of war or national emergency or other national or international calamity or crisis or change in economic or political conditions if the effect of such outbreak, escalation, declaration, emergency, calamity, crisis or change on the financial markets of the United States would, in your reasonable judgment, make it impracticable or inadvisable to market the Shares or to enforce contracts for the sale of the Shares, (iii) suspension of trading in securities generally on the New York Stock Exchange, the American Stock Exchange or the Nasdaq National Market or limitation on prices (other than limitations on hours or numbers of days of trading) for securities on either such Exchange, (iv) the enactment, publication, decree or other promulgation of any statute, regulation, rule or order of any court or other governmental authority which in your opinion materially and adversely affects or may materially and adversely affect the business or operations of the Company, (v) the declaration of a banking moratorium by United States or New York State authorities, (vi) the suspension of trading of the Company's common stock by the Nasdaq National Market, the Commission, or any other governmental authority, (vii) the taking of any action by any governmental body or agency in respect of its monetary or fiscal affairs which in your reasonable opinion has a material adverse effect on the securities markets in the United States or, (viii) a material disruption in securities settlement, payment or clearance services in the United States; or

(b) as provided in Sections 6 and 9 of this Agreement.

12. SUCCESSORS.

This Agreement has been and is made solely for the benefit of the Underwriters and the Company and their respective successors, executors, administrators, heirs and assigns, and the officers, directors and controlling persons referred to herein, and no other person will have any right or obligation hereunder. No purchaser of any of the Shares from any Underwriter shall be deemed a successor or assign merely because of such purchase.

13. INFORMATION PROVIDED BY UNDERWRITERS.

The Company and the Underwriters acknowledge and agree that the only information furnished or to be furnished by any Underwriter to the Company for inclusion in any Prospectus or the Registration Statement consists of the information set forth in the third and ninth through fifteenth paragraphs under the caption "Underwriting" in the Prospectus.

14. MISCELLANEOUS.

The reimbursement, indemnification and contribution agreements contained in this Agreement and the representations, warranties and covenants in this Agreement shall remain in full force and effect regardless of (a) any termination of this Agreement, (b) any investigation made by or on behalf of any Underwriter or controlling person thereof, or by or on behalf of the Company or its directors or officers and (c) delivery of and payment for the Shares under this Agreement.

This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but both of which together shall constitute one and the same instrument.

This Agreement shall be governed by, and construed in accordance with, the laws of the State of New York.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to us the enclosed duplicates hereof, whereupon it will become a binding agreement among the Company and the several Underwriters in accordance with its terms.

		Very truly yours,
		NITROMED, INC.
		By:	Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: President and Chief Executive Officer

The foregoing Underwriting Agreement
is hereby confirmed and accepted as
of the date first above written.

▇.▇. ▇▇▇▇▇▇ SECURITIES INC.
PACIFIC GROWTH EQUITIES, LLC
DEUTSCHE BANK SECURITIES INC.
BEAR, ▇▇▇▇▇▇▇ & CO. INC.

As Representatives of the several
Underwriters listed on Schedule I

By:		▇. ▇. ▇▇▇▇▇▇ Securities Inc.
By:		Name: Title:

SCHEDULE I

SCHEDULE OF UNDERWRITERS

Underwriter			Number of Firm Shares to be Purchased
▇.▇. ▇▇▇▇▇▇ Securities Inc.
Pacific Growth Equities, LLC
Deutsche Bank Securities Inc.
Bear, ▇▇▇▇▇▇▇ & Co. Inc.
	Total

SCHEDULE II

SHAREHOLDERS NOT AGREEING TO LOCKUP AGREEMENTS

▇▇▇▇ ▇▇▇▇▇▇▇ and Rho Ventures (lock-up of 45 days)

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EQUITY UNDERWRITING AGREEMENT

] Shares NitroMed, Inc. Common Stock ($ 0.01 Par Value) EQUITY UNDERWRITING AGREEMENT

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