Shares METABASIS THERAPEUTICS, INC. Common Stock UNDERWRITING AGREEMENT

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 1.1

Shares

METABASIS THERAPEUTICS, INC.

Common Stock

, 2004

▇▇ ▇▇▇▇▇ & CO., LLC
DEUTSCHE BANK SECURITIES INC.
▇▇▇▇▇▇ ▇▇▇▇▇▇ PARTNERS LLC
▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, INCORPORATED
As Representatives of the several Underwriters
c/o ▇▇ ▇▇▇▇▇ & Co., LLC
▇▇▇▇ ▇▇▇▇▇▇ ▇▇ ▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Dear Sirs:

1. INTRODUCTORY. Metabasis Therapeutics, Inc., a Delaware corporation (the "Company"), proposes to sell, pursuant to the terms of this Agreement, to the several underwriters named in Schedule A hereto (the "Underwriters," or, each, an "Underwriter"), an aggregate of shares of Common Stock, $0.001 par value (the "Common Stock") of the Company. The aggregate of shares so proposed to be sold is hereinafter referred to as the "Firm Stock". The Company also proposes to sell to the Underwriters, upon the terms and conditions set forth in Section 3 hereof, up to an additional shares of Common Stock (the "Optional Stock"). The Firm Stock and the Optional Stock are hereinafter collectively referred to as the "Stock". ▇▇ ▇▇▇▇▇ & Co., LLC ("▇▇ ▇▇▇▇▇"), Deutsche Bank Securities Inc., ▇▇▇▇▇▇ ▇▇▇▇▇▇ Partners LLC and ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, Incorporated are acting as representatives of the several Underwriters and in such capacity are hereinafter referred to as the "Representatives." As part of the offering contemplated by this Agreement, ▇▇ ▇▇▇▇▇ (the "Designated Underwriter") has agreed to reserve out of the Firm Stock purchased by it under this Agreement, up to shares, for sale to the Company's customers and business partners and friends of the Company's officers, directors and employees (collectively, "Participants"), as set forth in the Prospectus (as defined herein) under the heading "Underwriting" (the "Directed Share Program"). The Firm Stock to be sold by the Designated Underwriter pursuant to the Directed Share Program (the "Directed Shares") will be sold by the Designated Underwriter pursuant to this Agreement at the public offering price. Any Directed Shares not subscribed for by the end of the business day on which this Agreement is executed will be offered to the public by the Underwriters as set forth in the Prospectus.

2. REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company represents and warrants to, and agrees with, the several Underwriters that:

(a) A registration statement on Form S-1 (File No. 333- ) (the "Initial Registration Statement") in respect of the Stock has been filed with the Securities and Exchange Commission (the "Commission"); the Initial Registration Statement and any post-effective amendment thereto, each in the form heretofore delivered to you, and, excluding exhibits thereto, to you for each of the other Underwriters, have been declared effective by the Commission in such form; other than a registration statement, if any, increasing the size of the offering (a "Rule 462(b) Registration Statement"), filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the "Securities Act") and the rules and regulations (the "Rules and Regulations") of the Commission thereunder, which became effective upon filing, no other document with respect to the Initial Registration Statement has heretofore been filed with the Commission; and no stop order suspending the effectiveness of the Initial Registration Statement, any post-effective amendment thereto or the Rule 462(b) Registration Statement, if any, has been issued and no proceeding for

that purpose has been initiated or threatened by the Commission (any preliminary prospectus included in the Initial Registration Statement or filed with the Commission pursuant to Rule 424(a) of the Rules and Regulations, is hereinafter called a "Preliminary Prospectus"); the various parts of the Initial Registration Statement and the Rule 462(b) Registration Statement, if any, including all exhibits thereto and including the information contained in the form of final prospectus filed with the Commission pursuant to Rule 424(b) under the Securities Act and deemed by virtue of Rule 430A under the Securities Act to be part of the Initial Registration Statement at the time it was declared effective, each as amended at the time such part of the Initial Registration Statement became effective or such part of the Rule 462(b) Registration Statement, if any, became or hereafter becomes effective, are hereinafter collectively called the "Registration Statements"; and such final prospectus, in the form first filed pursuant to Rule 424(b) under the Securities Act, is hereinafter called the "Prospectus". No document has been or will be prepared or distributed in reliance on Rule 434 under the Securities Act. No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission.

(b) The Initial Registration Statement conforms (and the Rule 462(b) Registration Statement, if any, the Prospectus and any amendments or supplements to either of the Registration Statements or the Prospectus, when they become effective or are filed with the Commission, as the case may be, will conform) in all material respects to the requirements of the Securities Act and the Rules and Regulations and do not and will not, as of the applicable effective date (as to the Registration Statements and any amendment thereto) and as of the applicable filing date (as to the Prospectus and any amendment or supplement thereto) contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading; provided, however, that the foregoing representations and warranties shall not apply to information contained in or omitted from the Registration Statements or the Prospectus or any such amendment or supplement thereto in reliance upon, and in conformity with, written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriter's Information (as defined in Section 16).

(c) The Company and the Subsidiary (as defined below) have been duly incorporated and are validly existing as corporations in good standing under the laws of their respective jurisdictions of incorporation, are duly qualified to do business and are in good standing as foreign corporations in each jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such qualification, and have all power and authority necessary to own or hold their respective properties and to conduct the businesses in which they are engaged, except where the failure to so qualify or have such power or authority would not have, singularly or in the aggregate, a material adverse effect on the condition (financial or otherwise), results of operations, business or prospects of the Company and the Subsidiary taken as a whole (a "Material Adverse Effect"). The Company owns or controls, directly or indirectly, only the following corporations, partnerships, limited liability partnerships, limited liability companies, associations or other entities: Aramed, Inc., a Delaware corporation (the "Subsidiary").

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

(e) The Stock to be issued and sold by the Company to the Underwriters hereunder has been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued, fully paid and nonassessable and free of any preemptive or similar rights and will conform to the description thereof contained in the Prospectus.

(f) The Company has an authorized capitalization as set forth in the Prospectus, and all of the issued shares of capital stock of the Company have been duly and validly authorized and

issued, are fully paid and non-assessable, and conform to the description thereof contained in the Prospectus. None of the outstanding shares of Common Stock was issued in violation of any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. There are no authorized or outstanding options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or debt securities convertible into or exchangeable or exercisable for, any capital stock of the Company or the Subsidiary other than those accurately described in the Prospectus.

(g) All the outstanding shares of capital stock of the Subsidiary have been duly authorized and validly issued, are fully paid and nonassessable and, except to the extent set forth in the Prospectus, are owned by the Company directly, free and clear of any claim, lien, encumbrance, security interest, restriction upon voting or transfer or any other claim of any third party.

(h) The execution, delivery and performance of this Agreement by the Company and the consummation of the transactions contemplated hereby will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or the Subsidiary is a party or by which the Company or the Subsidiary is bound or to which any of the property or assets of the Company or the Subsidiary is subject, (ii) result in any violation of the provisions of the charter or by-laws of the Company or the Subsidiary or (iii) result in any violation of any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or the Subsidiary or any of their properties or assets, except where any such conflict, breach, violation or default described in clause (i) or (iii) would not have, singularly or in the aggregate, a Material Adverse Effect.

(i) Except for the registration of the Stock under the Securities Act and such consents, approvals, authorizations, registrations or qualifications as may be required under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and applicable state or foreign securities laws, the National Association of Securities Dealers, Inc. and the Nasdaq National Market in connection with the purchase and distribution of the Stock by the Underwriters, no consent, approval, authorization or order of, or filing or registration with, any such court or governmental agency or body is required for the execution, delivery and performance of this Agreement by the Company and the consummation of the transactions contemplated hereby.

(j) Ernst & Young LLP, who have expressed their opinions on the audited financial statements included in the Registration Statements and the Prospectus, are independent public accountants as required by the Securities Act and the Rules and Regulations.

(k) The financial statements, together with the related notes and any supporting schedules, included in the Prospectus and in each Registration Statement fairly present the financial position and the results of operations and changes in financial position of the Company and its consolidated subsidiaries, if any, at the respective dates or for the respective periods therein specified. Such statements and related notes and any schedules have been prepared in accordance with accounting principles generally accepted in the United States ("GAAP") applied on a consistent basis except as may be set forth in the Prospectus; provided, however, that statements that are unaudited are subject to year-end adjustments and do not contain footnotes required under GAAP. The financial statements, together with the related notes and any schedules, included in the Prospectus comply in all material respects with the Securities Act and the Rules and Regulations thereunder. No other financial statements or supporting schedules are required by the Securities Act or the Rules and Regulations thereunder to be included in the Prospectus.

(l) Neither the Company nor the Subsidiary has sustained, since the date of the latest audited financial statements included in the Prospectus, any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or

from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus; and, since such date, there has not been any change in the capital stock (other than issuances of options or Common Stock in the ordinary course of business and pursuant to equity incentive plans disclosed in the Prospectus or the issuance of Common Stock upon the exercise of outstanding options and warrants) or long-term debt of the Company or the Subsidiary or any material adverse change, or any development involving a prospective material adverse change, in or affecting the business, general affairs, management, financial position, stockholders' equity or results of operations of the Company and the Subsidiary taken as a whole, otherwise than as set forth or contemplated in the Prospectus.

(m) Except as set forth in the Prospectus, there is no legal or governmental proceeding pending to which the Company or the Subsidiary is a party or of which any property or assets of the Company or the Subsidiary is the subject which, singularly or in the aggregate, if determined adversely to the Company or the Subsidiary, might have a Material Adverse Effect or would prevent or adversely affect the ability of the Company to perform its obligations under this Agreement; and to the best of the Company's knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others.

(n) Neither the Company nor the Subsidiary (i) is in violation of its charter or by-laws, (ii) is in default in any respect, and no event has occurred which, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which it is a party or by which it is bound or to which any of its property or assets is subject or (iii) is in violation in any respect of any law, ordinance, governmental rule, regulation or court decree to which it or its property or assets may be subject except, in each of clauses (i) through (iii), for any violations or defaults which, singularly or in the aggregate, would not have a Material Adverse Effect.

(o) The Company or its collaborators possess or believe they can obtain in the ordinary course when required all licenses, certificates, approvals, clearances, authorizations, permits, consents and orders issued by, and have made all declarations and filings with, or will make in the ordinary course when required, the appropriate local, state, federal or foreign regulatory agencies or bodies in each jurisdiction where the Company's products, as described in the Prospectus, are being tested or are proposed to be sold as of the date hereof (each a "Permit") which are necessary or desirable for the ownership of the Company's properties or the conduct of the Company's business as described in the Prospectus (including those that may be required by the U. S. Food and Drug Administration (the "FDA"), any agency of any foreign government and any other foreign regulatory authority exercising authority comparable to that of the FDA (including any non-governmental entity whose approval or authorization is required under foreign law comparable to that administered by the FDA) and any state, federal or foreign agencies or bodies engaged in the regulation of pharmaceuticals) except where any failures to possess or make the same, singularly or in the aggregate, would not have a Material Adverse Effect. Each issued Permit, if any, is currently in full force and effect, and no proceeding has been instituted or is pending or, to the best of the Company's knowledge, is contemplated or threatened, which in any manner affects or draws into question the validity or effectiveness of any Permit or relates in any way to the revocation or modification thereof, and the Company has no reason to believe that any such Permit will not be renewed.

(p) Neither the Company nor the Subsidiary is or, after giving effect to the offering of the Stock and the application of the proceeds thereof as described in the Prospectus, will become an "investment company" within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(q) Neither the Company nor any of its officers, directors or, to the Company's knowledge, other affiliates has taken or will take, directly or indirectly, any action designed or intended to stabilize or manipulate the price of any security of the Company, or which caused or resulted in, or which might in the future reasonably be expected to cause or result in, stabilization or manipulation of the price of any security of the Company.

(r) The Company and the Subsidiary own or possess the right to use all patents, trademarks, trademark registrations, service marks, service ▇▇▇▇ registrations, trade names, copyrights, licenses, inventions, trade secrets and rights described in the Prospectus as being owned by them for the conduct of their respective businesses as now conducted and as proposed to be conducted or otherwise necessary or used in connection with the commercialization of the existing product candidates of the Company and the Subsidiary and the product candidates described in the Prospectus as being under development (collectively, the "Company Intellectual Property"), and the Company is not aware of any claim to the contrary or any challenge by any other person to the rights of the Company and the Subsidiary with respect to the foregoing. To the best of the Company's knowledge, none of the patents owned or licensed by the Company or the Subsidiary is unenforceable or invalid, and none of the patent applications owned or licensed by the Company or the Subsidiary would be unenforceable or invalid if issued as patents. Neither the Company nor the Subsidiary is obligated to pay a royalty, grant a license or provide other consideration to any third party in connection with the Company Intellectual Property other than as described in the Prospectus. To the best of the Company's knowledge and except as described in the Prospectus, the Company's business as now conducted and as proposed to be conducted does not and will not infringe or conflict with any patents, trademarks, service marks, trade names, copyrights, trade secrets, licenses or other intellectual property or franchise right of any person. Except as described in the Prospectus, no claim has been made against the Company alleging the infringement by the Company of any patent, trademark, service ▇▇▇▇, trade name, copyright, trade secret, license in or other intellectual property right or franchise right of any person.

(s) The studies, tests and preclinical and clinical trials conducted by or on behalf of the Company that are described in the Prospectus were and, if still pending, are being conducted in material compliance with all applicable local, state and federal laws, rules, regulations and guidance, including, but not limited to, the Federal Food, Drug and Cosmetic Act and implementing regulations at 21 C.F.R. Parts 50, 54, 56, 58 and 312. The descriptions of the results of such studies, tests and trials contained in the Prospectus are accurate and complete in all material respects. The Company is not aware of any studies, tests or trials the results of which reasonably call into question the clinical trial results described or referred to in the Prospectus when viewed in the context in which such results are described and the clinical state of development; 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.

(t) The Company and the Subsidiary have good and marketable title in fee simple to, or have valid rights to lease or otherwise use, all items of real or personal property which are material to the business of the Company and the Subsidiary taken as a whole, in each case free and clear of all liens, encumbrances, claims and defects that may result in a Material Adverse Effect.

(u) No labor disturbance by the employees of the Company or the Subsidiary exists or, to the best of the Company's knowledge, is imminent which would be expected to have a Material Adverse Effect. The Company is not aware that any key employee or significant group of employees of the Company or the Subsidiary plans to terminate employment with the Company or the Subsidiary.

(v) No "prohibited transaction" (as defined in Section 406 of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder ("ERISA"), or Section 4975 of the Internal Revenue Code of 1986, as amended from time to time (the "Code")) or "accumulated funding deficiency" (as defined in Section 302 of ERISA) or any of the events set forth in Section 4043(b) of ERISA (other than events with respect to which the 30-day notice requirement under Section 4043 of ERISA has been waived) has occurred with respect to any employee benefit plan which could have a Material Adverse Effect; each employee benefit plan is in compliance in all material respects with applicable law, including ERISA and the Code; the Company has not incurred and does not expect to incur liability under Title IV of ERISA with respect to the termination of, or withdrawal from, any "pension plan"; and each "pension plan" (as defined in ERISA) for which the Company 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 could cause the loss of such qualification.

(w) There has been no storage, generation, transportation, handling, treatment, disposal, discharge, emission, or other release of any kind of toxic or other wastes or other hazardous substances by, due to, or caused by the Company or the Subsidiary (or, to the best of the Company's knowledge, any other entity for whose acts or omissions the Company or the Subsidiary is or may be liable) upon any of the property now or previously owned or leased by the Company or the Subsidiary, or upon any other property, in violation of any statute or any ordinance, rule, regulation, order, judgment, decree or permit or which would, under any statute or any ordinance, rule (including rule of common law), regulation, order, judgment, decree or permit, give rise to any liability, except for any violation or liability which would not have, singularly or in the aggregate with all such violations and liabilities, a Material Adverse Effect; there has been no disposal, discharge, emission or other release of any kind onto such property or into the environment surrounding such property of any toxic or other wastes or other hazardous substances with respect to which the Company or the Subsidiary have knowledge, except for any such disposal, discharge, emission, or other release of any kind which would not have, singularly or in the aggregate with all such discharges and other releases, a Material Adverse Effect.

(x) The Company and the Subsidiary each (i) have filed all necessary federal, state and foreign income and franchise tax returns, (ii) have paid all federal state, local and foreign taxes due and payable, and (iii) do not have any tax deficiency or claims outstanding or assessed or, to the best of the Company's knowledge, proposed against it which would reasonably be expected to have a Material Adverse Effect.

(y) The Company and the Subsidiary carry, or are covered by, insurance in such amounts and covering such risks as is adequate for the conduct of their respective businesses and the value of their respective properties and as is customary for companies engaged in similar businesses in similar industries.

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

(aa) The minute books of the Company have been made available to the Underwriters and counsel for the Underwriters, and such books (i) contain a complete summary of all meetings and actions of the board of directors (including each board committee) and stockholders of the

Company since the time of its respective incorporation through the date of the latest meeting and action, and (ii) accurately in all material respects reflect all transactions referred to in such minutes.

(bb) There is no franchise, lease, contract, agreement or document required by the Securities Act or by the Rules and Regulations to be described in the Prospectus or to be filed as an exhibit to the Registration Statements which is not described or filed therein as required; and all descriptions of any such franchises, leases, contracts, agreements or documents contained in the Registration Statements are accurate and complete descriptions of such documents in all material respects. Other than as described in the Prospectus, no such franchise, lease, contract or agreement has been suspended or terminated for convenience or default by the Company or any of the other parties thereto, and the Company has not received notice nor does it have any other knowledge of any such pending or threatened suspension or termination, except for such pending or threatened suspensions or terminations that would not reasonably be expected to, singularly or in the aggregate, have a Material Adverse Effect.

(cc) No relationship, direct or indirect, exists between or among the Company on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company on the other hand, which is required to be described in the Prospectus and which is not so described.

(dd) No person or entity has the right to require registration of shares of Common Stock or other securities of the Company concurrent with or as a result of the offering of the Stock, except as described in the Prospectus and except for persons and entities who have expressly waived such right or who have been given timely and proper notice and have failed to exercise such right within the time or times required under the terms and conditions of such right.

(ee) Neither the Company nor the Subsidiary own any "margin securities" as that term is defined in Regulation U of the Board of Governors of the Federal Reserve System (the "Federal Reserve Board"), and none of the proceeds of the sale of the Stock will be used, directly or indirectly, for the purpose of purchasing or carrying any margin security, for the purpose of reducing or retiring any indebtedness which was originally incurred to purchase or carry any margin security or for any other purpose which might cause any of the Securities to be considered a "purpose credit" within the meanings of Regulation T, U or X of the Federal Reserve Board.

(ff) Other than this Agreement, neither the Company nor the Subsidiary is a party to any contract, agreement or understanding with any person that would give rise to a valid claim against the Company or the Underwriters for a brokerage commission, finder's fee or like payment in connection with the offering and sale of the Stock.

(gg) No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(hh) The Stock has been approved for listing subject to notice of issuance on the NASDAQ Stock Market's National Market (the "Nasdaq National Market").

(ii) The Company has taken all necessary actions to ensure that, upon and at all times after the effectiveness of the Registration Statement, it and its directors and officers (in their capacities as such) will be in compliance with all applicable provisions of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act of 2002 and all rules and regulations promulgated thereunder or implementing the provisions thereof (the "▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act") that are then in effect and is actively taking steps to ensure that it and its directors and officers (in their capacities as such) will be in compliance with other applicable provisions of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act not currently in effect upon and at all times after the effectiveness of such provisions.

(jj) The Company has taken all necessary actions to ensure that, upon and at all times after the Nasdaq National Market shall have approved the Stock for inclusion, it will be in compliance with all applicable corporate governance requirements set forth in the Nasdaq Marketplace Rules that are then in effect and is actively taking steps to ensure that it will be in compliance with other applicable corporate governance requirements set forth in the Nasdaq Marketplace Rules not currently in effect upon and all times after the effectiveness of such requirements.

(kk) The Company has taken all necessary actions to ensure that, upon and at all times after the effectiveness of the Registration Statement, it will establish and maintain disclosure controls and procedures (as such term is defined in Rules 13a-15 and 15d-15 under the Exchange Act); such disclosure controls and procedures will be designed to ensure that material information relating to the Company, including any consolidated subsidiaries, is made known to the Company's principal executive officer and its principal financial officer by others within those entities, and such disclosure controls and procedures are effective to perform the functions for which they were established; the Company's auditors and the Audit Committee of the Board of Directors will be timely advised of: (i) any significant deficiencies in the design or operation of internal controls which could adversely affect the Company's ability to record, process, summarize, and report financial data; and (ii) any fraud, whether or not material, that involves management or other employees who have a role in the Company's internal controls; any material weaknesses in internal controls will be identified for the Company's auditors.

(ll) Neither the Company nor the Subsidiary nor, to the best of the Company's knowledge, any employee or agent of the Company or the Subsidiary, has made any contribution or other payment to any official of, or candidate for, any federal, state or foreign office in violation of any law or of the character required to be disclosed in the Prospectus.

(mm) There are no transactions, arrangements or other relationships between and/or among the Company, any of its affiliates (as such term is defined in Rule 405 of the Securities Act) and any unconsolidated entity, including, but not limited to, any structure finance, special purpose or limited purpose entity that could reasonably be expected to materially affect the Company's liquidity or the availability of or requirements for its capital resources required to be described in the Prospectus which have not been described as required.

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

(oo) The Registration Statements, the Prospectus and the Preliminary Prospectus comply, and any further amendments or supplements thereto will comply, with any applicable laws or regulations of foreign jurisdictions in which they are distributed in connection with the Directed Share Program. No authorization, approval, consent, license, order, registration or qualification of or with any government, governmental instrumentality or court, other than such as have been obtained, is necessary under the securities laws or regulations of any foreign jurisdiction in which the Directed Shares are offered outside the United States.

(pp) The Company has not offered, or caused the Underwriters to offer, any Firm Stock to any person pursuant to the Directed Share Program with the specific intent to unlawfully influence (i) a customer or business partner of the Company to alter the customer's or business partner's level or type of business with the Company or (ii) a trade journalist or publication to write or publish favorable information about the Company or its products.

3. PURCHASE SALE AND DELIVERY OF OFFERED SECURITIES. On the basis of the representations, warranties and agreements herein contained, but subject to the terms and conditions herein set forth, the Company agrees to sell to each Underwriter, and each Underwriter agrees,

severally and not jointly, to purchase from the Company that number of shares of Firm Stock (rounded up or down, as determined by ▇▇ ▇▇▇▇▇ in its discretion, in order to avoid fractions) obtained by multiplying shares of Firm Stock by a fraction the numerator of which is the number of shares of Firm Stock set forth opposite the name of such Underwriter in Schedule A hereto and the denominator of which is the total number of shares of Firm Stock.

The purchase price per share to be paid by the Underwriters to the Company for the Stock will be $ per share (the "Purchase Price").

The Company will deliver the Firm Stock to the Representatives for the respective accounts of the several Underwriters in the form of definitive certificates, issued in such names and in such denominations as the Representatives may direct by notice in writing to the Company given at or prior to 12:00 Noon, New York time, on the second full business day preceding the First Closing Date (as defined below) against payment of the aggregate Purchase Price therefor in federal (same day) funds by wire transfer to an account at a bank acceptable to ▇▇ ▇▇▇▇▇, payable to the order of the Company, all at the offices of ▇▇▇▇▇▇ Godward LLP, ▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligations of each Underwriter hereunder. The time and date of the delivery and closing shall be at 10:00 A.M., New York time, on , 2004, in accordance with Rule 15c6-1 of the Exchange Act. The time and date of such payment and delivery are herein referred to as the "First Closing Date". The First Closing Date and the location of delivery of, and the form of payment for, the Firm Stock may be varied by agreement between the Company and ▇▇ ▇▇▇▇▇.

The Company shall make the certificates for the Firm Stock available to the Representatives for examination on behalf of the Underwriters in New York, New York at least twenty-four hours prior to the First Closing Date.

For the purpose of covering any over-allotments in connection with the distribution and sale of the Firm Stock as contemplated by the Prospectus, the Underwriters may purchase all or less than all of the Optional Stock. The price per share to be paid for the Optional Stock shall be the Purchase Price. The Company agrees to sell to the Underwriters the number of shares of Optional Stock specified in the written notice by ▇▇ ▇▇▇▇▇ described below and the Underwriters agree, severally and not jointly, to purchase such shares of Optional Stock. Such shares of Optional Stock shall be purchased from the Company for the account of each Underwriter in the same proportion as the number of shares of Firm Stock set forth opposite such Underwriter's name bears to the total number of shares of Firm Stock (subject to adjustment by ▇▇ ▇▇▇▇▇ to eliminate fractions). The option granted hereby may be exercised as to all or any part of the Optional Stock at any time, and from time to time, not more than thirty (30) days subsequent to the date of this Agreement. No Optional Stock shall be sold and delivered unless the Firm Stock previously has been, or simultaneously is, sold and delivered. The right to purchase the Optional Stock or any portion thereof may be surrendered and terminated at any time upon notice by ▇▇ ▇▇▇▇▇ to the Company.

The option granted hereby may be exercised by written notice being given to the Company by ▇▇ ▇▇▇▇▇ setting forth the number of shares of the Optional Stock to be purchased by the Underwriters and the date and time for delivery of and payment for the Optional Stock. Each date and time for delivery of and payment for the Optional Stock (which may be the First Closing Date, but not earlier) is herein called the "Option Closing Date" and shall in no event be earlier than two (2) business days nor later than five (5) business days after written notice is given. (The Option Closing Date and the First Closing Date are herein called the "Closing Dates".)

The Company will deliver the Optional Stock to the Underwriters in the form of definitive certificates, issued in such names and in such denominations as the Representatives may direct by notice in writing to the Company given at or prior to 12:00 Noon, New York time, on the second full business day preceding the Option Closing Date against payment of the aggregate Purchase Price

therefor in federal (same day) funds by wire transfer to an account at a bank acceptable to ▇▇ ▇▇▇▇▇ payable to the order of the Company all at the offices of ▇▇▇▇▇▇ Godward LLP. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligations of each Underwriter hereunder. The Company shall make the certificates for the Optional Stock available to the Representatives for examination on behalf of the Underwriters in New York, New York not later than 10:00 A.M., New York Time, on the business day preceding the Option Closing Date. The Option Closing Date and the location of delivery of, and the form of payment for, the Optional Stock may be varied by agreement between the Company and ▇▇ ▇▇▇▇▇.

The several Underwriters propose to offer the Stock for sale upon the terms and conditions set forth in the Prospectus.

4. FURTHER AGREEMENTS OF THE COMPANY. The Company agrees with the several Underwriters that:

(a) The Company will prepare the Rule 462(b) Registration Statement, if necessary, in a form approved by the Representatives and file such Rule 462(b) Registration Statement with the Commission on the date hereof; prepare the Prospectus in a form approved by the Representatives and file such Prospectus pursuant to Rule 424(b) under the Securities Act not later than the second business day following the execution and delivery of this Agreement; make no further amendment or any supplement to the Registration Statements or to the Prospectus to which the Representatives shall reasonably object by notice to the Company after a reasonable period to review; advise the Representatives, promptly after it receives notice thereof, of the time when any amendment to either Registration Statement has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed and to furnish the Representatives with copies thereof; advise the Representatives, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or the Prospectus, of the suspension of the qualification of the Stock for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statements or the Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or the Prospectus or suspending any such qualification, use promptly its best efforts to obtain its withdrawal.

(b) If at any time prior to the expiration of nine months after the effective date of the Initial Registration Statement when a prospectus relating to the Stock is required to be delivered any event occurs as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact, or omit to state any material fact necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, or if it is necessary at any time to amend the Prospectus to comply with the Securities Act, the Company will promptly notify the Representatives thereof and upon their request will prepare an amended or supplemented Prospectus which will correct such statement or omission or effect such compliance. The Company will furnish without charge to each Underwriter and to any dealer in securities as many copies as the Representatives may from time to time reasonably request of such amended or supplemented Prospectus; and in case any Underwriter is required to deliver a prospectus relating to the Stock nine months or more after the effective date of the Initial Registration Statement, the Company upon the request of the Representatives and at the expense of such Underwriter will prepare promptly an amended or supplemented Prospectus as may be necessary to permit compliance with the requirements of Section 10(a)(3) of the Securities Act.

(c) To furnish promptly to each of the Representatives and to counsel for the Underwriters a signed copy of each of the Registration Statements as originally filed with the Commission, and

each amendment thereto filed with the Commission, including all consents and exhibits filed therewith.

(d) To deliver promptly to the Representatives in New York City such number of the following documents as the Representatives shall reasonably request: (i) conformed copies of the Registration Statements as originally filed with the Commission and each amendment thereto (in each case excluding exhibits), (ii) each Preliminary Prospectus and (iii) the Prospectus (not later than 10:00 A.M., New York time, of the business day following the execution and delivery of this Agreement) and any amended or supplemented Prospectus (not later than 10:00 A.M., New York City time, on the business day following the date of such amendment or supplement).

(e) To make generally available to its stockholders as soon as practicable, but in any event not later than eighteen months after the effective date of the Registration Statement (as defined in Rule 158(c) under the Securities Act), an earnings statement of the Company and the Subsidiary (which need not be audited) complying with Section 11(a) of the Securities Act and the Rules and Regulations (including, at the option of the Company, Rule 158).

(f) The Company will promptly take from time to time such actions as the Representatives may reasonably request to qualify the Stock for offering and sale under the securities or Blue Sky laws of such jurisdictions as the Representatives may designate and to continue such qualifications in effect for so long as required for the distribution of the Stock; provided that the Company and the Subsidiary shall not be obligated to qualify as foreign corporations in any jurisdiction in which they are not so qualified or to file a general consent to service of process in any jurisdiction.

(g) To the extent that any such reports, financial statements or other communications are not available through the Commission's Electronic Data Gathering and Retrieval System ("▇▇▇▇▇") or any system succeeding or replacing ▇▇▇▇▇, during the period of five years from the date hereof, the Company will deliver to the Representatives and, upon request, to each of the other Underwriters, (i) as soon as they are available, copies of all reports or other communications furnished to stockholders and (ii) as soon as they are available, copies of any reports and financial statements furnished or filed with the Commission pursuant to the Exchange Act or any national securities exchange or automatic quotation system on which the Stock is listed or quoted.

(h) The Company will not directly or indirectly offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of any shares of Common Stock or securities convertible into or exercisable or exchangeable for Common Stock for a period of 180 days from the date of the Prospectus without the prior written consent of ▇▇ ▇▇▇▇▇ other than the Company's sale of the Stock hereunder and the issuance of shares pursuant to (i) employee benefit plans, equity incentive plans or other employee compensation plans existing on the date hereof or described in the Prospectus, (ii) currently outstanding options, warrants or rights or (iii) a strategic partnership, joint venture, collaboration, lending or similar arrangement, or in connection with the acquisition or license by the Company of any business, products or technologies, provided that (A) the Company may not issue shares of Common Stock, or securities convertible into or exercisable or exchangeable for shares of Common Stock (and treating these securities as if converted into or exercised or exchanged for Common Stock), in excess of 5% of the Common Stock outstanding immediately following the sale of the Stock (treating all securities as if converted into or exercised or exchanged for Common Stock) and (B) the transferee shall furnish to the Representatives, prior to any such transfer, a letter, substantially in the form of Exhibit I hereto. The Company will cause each officer, director and stockholder listed in Schedule B to furnish to the Representatives, prior to the First Closing Date, a letter, substantially in the form of Exhibit I hereto.

(i) The Company will supply the Representatives with copies of all correspondence to and from, and all documents issued to and by, the Commission in connection with the registration of the Stock under the Securities Act.

(j) Prior to each of the Closing Dates the Company will furnish to the Representatives, as soon as they have been prepared, copies of any unaudited interim consolidated financial statements of the Company for any periods subsequent to the periods covered by the financial statements appearing in the Registration Statement and the Prospectus.

(k) Prior to each of the Closing Dates, the Company will not issue any press release or other communication directly or indirectly or hold any press conference with respect to the Company, its condition, financial or otherwise, or earnings, business affairs or business prospects (except for routine oral marketing communications in the ordinary course of business and consistent with the past practices of the Company and of which the Representatives are notified), without the prior written consent of the Representatives, unless in the judgment of the Company and its counsel, and after notification to the Representatives, such press release or communication is required by law.

(l) In connection with the offering of the Stock, until ▇▇ ▇▇▇▇▇ shall have notified the Company of the completion of the resale of the Stock, the Company will not, and will cause its affiliated purchasers (as defined in Regulation M under the Exchange Act) not to, either alone or with one or more other persons, bid for or purchase, for any account in which it or any of its affiliated purchasers has a beneficial interest, any Stock, or attempt to induce any person to purchase any Stock, and not to, and to cause its affiliated purchasers not to, make bids or purchase for the purpose of creating actual, or apparent, active trading in or of raising the price of the Stock.

(m) The Company will not take any action prior to the Option Closing Date which would require the Prospectus to be amended or supplemented pursuant to Section 4(b).

(n) The Company shall at all times comply with all applicable provisions of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act in effect from time to time.

(o) The Company will apply the net proceeds from the sale of the Stock as set forth in the Prospectus under the heading "Use of Proceeds".

(p) In connection with the Directed Share Program, the Company will ensure that the Directed Shares will be restricted to the extent required by the NASD or the NASD rules from sale, transfer, assignment, pledge or hypothecation for a period of three (3) months following the date of the effectiveness of the Registration Statement. The Designated Underwriter will notify the Company as to which Participants will need to be so restricted. The Company will direct the transfer agent to place stop transfer restrictions upon such securities for such period of time.

(q) The Company will pay all fees and disbursements of counsel incurred by the Underwriters in connection with the Directed Share Program and stamp duties, similar taxes or duties or other taxes, if any, incurred by the Underwriters in connection with the Directed Share Program.

(r) The Company will comply with all applicable securities and other applicable securities and other laws, rules and regulations in each foreign jurisdiction in which the Directed Shares are offered in connection with the Directed Share Program.

5. PAYMENT OF EXPENSES. The Company agrees with the Underwriters to pay (a) the costs incident to the authorization, issuance, sale, preparation and delivery of the Stock and any taxes payable in that connection; (b) the costs incident to the registration of the Stock under the Securities Act; (c) the costs incident to the preparation, printing and distribution of the Registration Statement, Preliminary Prospectus, Prospectus and any amendments and exhibits thereto; (d) the costs of printing, reproducing and distributing the "Agreement Among Underwriters" between the Representatives and the Underwriters, the Master Selected Dealers' Agreement, the Underwriters' Questionnaire and this Agreement by mail, telex or other means of communications; (e) the fees and expenses (including

related fees and expenses of counsel for the Underwriters) incurred in connection with filings made with the National Association of Securities Dealers; (f) any applicable listing or other fees; (g) the fees and expenses of qualifying the Stock under the securities laws of the several jurisdictions as provided in Section 4(f) and of preparing, printing and distributing Blue Sky Memoranda and Legal Investment Surveys (including related fees and expenses of counsel to the Underwriters); (h) all fees and expenses of the registrar and transfer agent of the Stock; and (i) all other costs and expenses incident to the performance of the obligations of the Company under this Agreement (including, without limitation, the fees and expenses of the Company's counsel and the Company's independent accountants); provided that, except as otherwise provided in this Section 5 and in Section 9, the Underwriters shall pay their own costs and expenses, including the fees and expenses of their counsel, any transfer taxes on the Stock which they may sell and the expenses of advertising any offering of the Stock made by the Underwriters.

6. CONDITIONS OF UNDERWRITERS' OBLIGATIONS. The respective obligations of the several Underwriters hereunder are subject to the accuracy, when made and on each of the Closing Dates, of the representations and warranties of the Company contained herein, to the accuracy of the statements of the Company made in any certificates pursuant to the provisions hereof, to the performance by the Company of their obligations hereunder, and to each of the following additional terms and conditions:

(a) No stop order suspending the effectiveness of either of the Registration Statements shall have been issued and no proceedings for that purpose shall have been initiated or threatened by the Commission, and any request for additional information on the part of the Commission (to be included in the Registration Statements or the Prospectus or otherwise) shall have been complied with to the reasonable satisfaction of the Representatives. The Rule 462(b) Registration Statement, if any, and the Prospectus shall have been timely filed with the Commission in accordance with Section 4(a).

(b) None of the Underwriters shall have discovered and disclosed to the Company on or prior to the Closing Date that the Registration Statement or the Prospectus or any amendment or supplement thereto contains an untrue statement of a fact which, in the opinion of counsel for the Underwriters, is material or omits to state any fact which, in the opinion of such counsel, is material and is required to be stated therein or is necessary to make the statements therein not misleading.

(c) All corporate proceedings and other legal matters incident to the authorization, form and validity of each of this Agreement, the Stock, the Registration Statement and the Prospectus and all other legal matters relating to this Agreement and the transactions contemplated hereby shall be reasonably satisfactory in all material respects to counsel for the Underwriters, and the Company shall have furnished to such counsel all documents and information that they may reasonably request to enable them to pass upon such matters.

(d) ▇▇▇▇▇▇ Godward LLP shall have furnished to the Representatives such counsel's written opinion, as counsel to the Company, addressed to the Underwriters and dated each Closing Date, in substantially the form attached hereto as Exhibit II.

(e) Paul, Hastings, ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇ LLP shall have furnished to the Representatives such counsel's written opinion, as special patent counsel to the Company, addressed to the Underwriters and dated each Closing Date, in substantially the form attached hereto as Exhibit III.

(f) The Representatives shall have received from ▇▇▇▇▇▇ & ▇▇▇▇▇▇▇ LLP, counsel for the Underwriters, such opinion or opinions, dated each Closing Date, with respect to such matters as the Underwriters may reasonably require, and the Company shall have furnished to such counsel such documents as they may reasonably request for enabling them to pass upon such matters.

(g) At the time of the execution of this Agreement, the Representatives shall have received from Ernst & Young LLP a letter, addressed to the Underwriters and dated such date, in form and substance satisfactory to the Representatives (i) confirming that they are independent certified public accountants with respect to the Company within the meaning of the Securities Act and the Rules and Regulations and (ii) stating the conclusions and findings of such firm with respect to the financial statements and certain financial information contained in the Prospectus.

(h) On each Closing Date, the Representatives shall have received a letter (the "bring-down letter") from Ernst & Young LLP addressed to the Underwriters and dated such Closing Date confirming, as of the date of the bring-down letter (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in the Prospectus as of a date not more than three business days prior to the date of the bring-down letter), the conclusions and findings of such firm with respect to the financial information and other matters covered by its letter delivered to the Representatives concurrently with the execution of this Agreement pursuant to Section 6(g).

(i) The Company shall have furnished to the Representatives a certificate, dated each Closing Date, of its Chief Executive Officer and its Chief Financial Officer stating that (i) such officers have carefully examined the Registration Statements and the Prospectus and, in their opinion, the Registration Statements as of their respective effective dates and the Prospectus, as of its date, 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 to make the statements therein not misleading, (ii) since the effective date of the Initial Registration Statement, no event has occurred which should have been set forth in a supplement or amendment to the Registration Statements or the Prospectus, (iii) to the best of their knowledge after reasonable investigation, as of such Closing Date, the representations and warranties of the Company in this Agreement are true and correct and the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date, and (iv) subsequent to the date of the most recent financial statements included in the Prospectus, there has been no material adverse change in the financial position or results of operation of the Company and the Subsidiary, or any change, or any development including a prospective change, in or affecting the condition (financial or otherwise), results of operations, business or prospects of the Company and the Subsidiary taken as a whole, except as set forth in the Prospectus.

(j) (i) Neither the Company nor the Subsidiary shall have sustained since the date of the latest audited financial statements included in the Prospectus any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus, and (ii) since such date there shall not have been any change in the capital stock, short-term debt or long-term debt of the Company or the Subsidiary or any change, or any development involving a prospective change, in or affecting the business, general affairs, management, financial position, stockholders' equity or results of operations of the Company and the Subsidiary, otherwise than as set forth or contemplated in the Prospectus, the effect of which, in any such case described in clause (i) or (ii), is, in the judgment of the Representatives, so material and adverse as to make it impracticable or inadvisable to proceed with the sale or delivery of the Stock on the terms and in the manner contemplated in the Prospectus.

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

issuance or sale of the Stock or materially and adversely affect or potentially materially and adversely affect the business or operations of the Company.

(l) If applicable, subsequent to the execution and delivery of this Agreement, (i) no downgrading shall have occurred in the Company's corporate credit rating or the rating accorded the Company's debt securities by any "nationally recognized statistical rating organization," as that term is defined by the Commission for purposes of Rule 436(g)(2) of the Rules and Regulations and (ii) no such organization shall have publicly announced that it has under surveillance or review (other than an announcement with positive implications of a possible upgrading), its rating of any of the Company's debt securities.

(m) Subsequent to the execution and delivery of this Agreement, there shall not have occurred any of the following: (i) trading in securities generally on the New York Stock Exchange or the American Stock Exchange or in the over-the-counter market, or trading in any securities of the Company on any exchange or in the over-the-counter market, shall have been suspended or minimum or maximum prices or maximum range for prices shall have been established on any such exchange or such market by the Commission, by such exchange or by any other regulatory body or governmental authority having jurisdiction, (ii) a banking moratorium shall have been declared by federal or state authorities or a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States, (iii) (A) a declaration of a national emergency or war by the United States, or an outbreak or escalation of hostilities between the United States and any foreign power, (B) an outbreak or escalation of any other insurrection or armed conflict, or act of terrorism involving the United States, or any other national or international crisis, calamity or emergency or (C) any material change in the political conditions, financial markets or economic conditions in the United States which, in the case of (A), (B) or (C) above, in the sole judgment of the Representatives, makes it impracticable or inadvisable to proceed with the sale or the delivery of the Stock on the terms and in the manner contemplated in the Prospectus or (iv) there shall have occurred such a material adverse change in general economic, political or financial conditions (or the effect of international conditions on the financial markets in the United States shall be such) as to make it, in the judgment of the Representatives, impracticable or inadvisable to proceed with the sale or delivery of the Stock on the terms and in the manner contemplated in the Prospectus.

(n) The National Market System shall have approved the Stock for inclusion, subject only to official notice of issuance and evidence of satisfactory distribution.

(o) The Representatives shall have received the written agreements, substantially in the form of Exhibit I hereto, of the officers, directors and stockholders of the Company listed in Schedule B to this Agreement.

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

7. INDEMNIFICATION AND CONTRIBUTION.

(a) The Company shall indemnify and hold harmless each Underwriter, its officers, employees, representatives and agents and each person, if any, who controls any Underwriter within the meaning of the Securities Act (collectively the "Underwriter Indemnified Parties" and, each an "Underwriter Indemnified Party") against any loss, claim, damage or liability, joint or several, or any action in respect thereof, to which that Underwriter Indemnified Party may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Preliminary Prospectus, either of the Registration Statements or the

Prospectus or in any amendment or supplement thereto or (ii) the omission or alleged omission to state in any Preliminary Prospectus, either of the Registration Statements or the Prospectus or in any amendment or supplement thereto a material fact required to be stated therein or necessary to make the statements therein not misleading 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 Stock 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 in the case of any matter covered by 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 act or failure to act undertaken or omitted to be taken by such Underwriter through its gross negligence or willful misconduct) and shall reimburse each Underwriter Indemnified Party promptly upon demand for any legal or other expenses reasonably incurred by that Underwriter Indemnified Party in connection with investigating or preparing to defend or defending against or appearing as a third party witness in connection with any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage, liability or action arises out of or is based upon an untrue statement or alleged untrue statement in or omission or alleged omission from the Preliminary Prospectus, either of the Registration Statements or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for use therein, which information the parties hereto agree is limited to the Underwriter's Information (as defined in Section 16); provided, further however, that the foregoing indemnification agreement with respect to the Preliminary Prospectus shall not inure to the benefit of any Underwriter from which the person asserting any such loss, claim, damage or liability purchased Stock, or any officers, employees, representatives, agents or controlling persons of such Underwriter, if (i) a copy of the Prospectus (as then amended or supplemented) was required by law to be delivered to such person at or prior to the written confirmation of the sale of Stock to such person, (ii) a copy of the Prospectus (as then amended or supplemented) was not sent or given to such person by or on behalf of such Underwriter and such failure was not due to non-compliance by the Company with Section 4(d), and (iii) the Prospectus (as so amended or supplemented) would have cured the defect giving rise to such loss, claim, damage or liability.

The Company shall indemnify and hold harmless the Designated Underwriter and its officers, employees, representatives and agents and each person, if any, who controls any Underwriter within the meaning of the Securities Act (collectively the "Designated Underwriter Indemnified Parties," and each a "Designated Underwriter Indemnified Party") against any loss, claim, damage or liability, joint or several, or any action in respect thereof, to which that Designated Underwriter Indemnified Party may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in any material prepared by or with the consent of the Company for distribution to Participants in connection with the Directed Share Program, (ii) the omission or alleged omission to state in any material prepared by or with the consent of the Company for distribution to Participants in connection with the Directed Share Program a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (iii) the failure of any Participant to pay for and accept delivery of Directed Shares that the Participant agreed to purchase; or (iv) any other loss, claim, damage or liability, or any action in respect of, related to, arising out of, or in connection with the Directed Share Program, other than such losses, claims, damages or liabilities (or expenses relating thereto) that are finally judicially determined to have resulted from the willful misconduct or gross negligence of the Designated Underwriter.

This indemnity agreement is not exclusive and will be in addition to any liability which the Company might otherwise have and shall not limit any rights or remedies which may otherwise be available at law or in equity to each Underwriter Indemnified Party.

(b) Each Underwriter, severally and not jointly, shall indemnify and hold harmless the Company, its officers, employees, representatives and agents, each of its directors and each person, if any, who controls the Company within the meaning of the Securities Act (collectively the "Company Indemnified Parties" and each a "Company Indemnified Party") against any loss, claim, damage or liability, joint or several, or any action in respect thereof, to which the Company Indemnified Parties may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Preliminary Prospectus, either of the Registration Statements or the Prospectus or in any amendment or supplement thereto or (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, but in each case only to the extent that the untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of that Underwriter specifically for use therein, and shall reimburse the Company Indemnified Parties promptly upon demand for any legal or other expenses reasonably incurred by such parties in connection with investigating or preparing to defend or defending against or appearing as third party witness in connection with any such loss, claim, damage, liability or action as such expenses are incurred; provided that the parties hereto hereby agree that such written information provided by the Underwriters consists solely of the Underwriter's Information. This indemnity agreement is not exclusive and will be in addition to any liability which the Underwriters might otherwise have and shall not limit any rights or remedies which may otherwise be available at law or in equity to the Company Indemnified Parties.

(c) Promptly after receipt by an indemnified party under this Section 7 of notice of any claim or the commencement of any action, the indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under this Section 7, notify the indemnifying party in writing of the claim or the commencement of that action; provided, however, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have under this Section 7 except to the extent it has been materially prejudiced by such failure; and, provided, further, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have to an indemnified party otherwise than under this Section 7. If any such claim or action shall be brought against an indemnified party, and it shall notify the indemnifying party thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it wishes, jointly with any other similarly notified indemnifying party, to assume the defense thereof with counsel reasonably satisfactory to the indemnified party. After notice from the indemnifying party to the indemnified party of its election to assume the defense of such claim or action, the indemnifying party shall not be liable to the indemnified party under this Section 7 for any legal or other expenses subsequently incurred by the indemnified party in connection with the defense thereof other than reasonable costs of investigation; provided, however, that any indemnified party shall have the right to employ separate counsel in any such action and to participate in the defense thereof but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the employment thereof has been specifically authorized by the indemnifying party in writing, (ii) such indemnified party shall have been advised by such counsel that there may be one or more legal defenses available to it which are different from or additional to those available to the indemnifying party and in the reasonable judgment of such counsel it is advisable for such indemnified party to employ separate counsel or (iii) the indemnifying party has failed to assume the defense of such action and employ counsel reasonably satisfactory to the indemnified party, in

which case, if such indemnified party notifies the indemnifying party in writing that it elects to employ separate counsel at the expense of the indemnifying party, the indemnifying party shall not have the right to assume the defense of such action on behalf of such indemnified party, it being understood, however, that the indemnifying party shall not, in connection with any one such action or separate but substantially similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expenses of more than one separate firm of attorneys at any time for all such indemnified parties, which firm shall be designated in writing by ▇▇ ▇▇▇▇▇, if the indemnified parties under this Section 7 consist of any Underwriter Indemnified Party, or by the Company if the indemnified parties under this Section 7 consist of any Company Indemnified Parties. Each indemnified party, as a condition of the indemnity agreements contained in Sections 7(a) and 7(b), shall use all reasonable efforts to cooperate with the indemnifying party in the defense of any such action or claim. Subject to the provisions of Section 7(d) below, no indemnifying party shall be liable for any settlement of any such action effected without its written consent (which consent shall not be unreasonably withheld), but if settled with its written consent or if there be a final judgment for the plaintiff in any such action, the indemnifying party agrees to indemnify and hold harmless any indemnified party from and against any loss or liability by reason of such settlement or judgment.

Notwithstanding anything contained herein to the contrary, if indemnity may be sought pursuant to the penultimate paragraph in Section 7(a) hereof in respect of such action or proceeding, then in addition to such separate firm for the indemnified parties, the indemnifying party shall be liable for the reasonable fees and expenses of not more than one separate firm (in addition to any local counsel) for the Designated Underwriter, and all persons, if any, who control the Designated Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, for the defense of any losses, claims, damages and liabilities arising out of the Directed Share Program.

(d) If at any time an indemnified party shall have requested that an indemnifying party reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by this Section 7 effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the request for reimbursement, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

(e) If the indemnification provided for in this Section 7 is unavailable or insufficient to hold harmless an indemnified party under Section 7(a) or 7(b), then each indemnifying party shall, in lieu of indemnifying such indemnified party, contribute to the amount paid or payable by such indemnified party as a result of such loss, claim, damage or liability, or action in respect thereof, (i) in such proportion as shall be 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 Stock or, if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and the Underwriters on the other with respect to the statements or omissions which resulted in such loss, claim, damage or liability, or action 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 with respect to such offering shall be deemed to be in the same proportion as the total net proceeds from the offering of the Stock purchased under this Agreement (before deducting expenses) received by the Company bear to the total underwriting discounts and commissions received by the Underwriters with respect to the Stock purchased under this Agreement, 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, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such untrue statement or omission; provided that the parties hereto agree that the written information furnished to the Company through the Representatives by or on behalf of the Underwriters for use in any Preliminary Prospectus, either of the Registration Statements or the Prospectus consists solely of the Underwriter's Information. The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this Section 7(e) were to be 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 into account the equitable considerations referred to herein. The amount paid or payable by an indemnified party as a result of the loss, claim, damage or liability, or action in respect thereof, referred to above in this Section 7(e) shall be deemed to include, for purposes of this Section 7(e), 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 Section 7(e), no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Stock underwritten by it and distributed to the public were offered to the public less the amount of any damages which such Underwriter has otherwise paid or become liable to pay by reason of any untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

The Underwriters' obligations to contribute as provided in this Section 7(e) are several in proportion to their respective underwriting obligations and not joint.

8. TERMINATION. The obligations of the Underwriters hereunder may be terminated by ▇▇ ▇▇▇▇▇, in its absolute discretion by notice given to and received by the Company prior to delivery of and payment for the Firm Stock if, prior to that time, any of the events described in Sections 6(j), 6(l) or 6(m) have occurred or if the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement.

9. REIMBURSEMENT OF UNDERWRITERS' EXPENSES. If (a) this Agreement shall have been terminated pursuant to Section 8 or 10, (b) the Company shall fail to tender the Stock for delivery to the Underwriters for any reason not permitted under this Agreement, or (c) the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement, the Company shall reimburse the Underwriters for the fees and expenses of their counsel and for such other out-of-pocket expenses as shall have been reasonably incurred by them in connection with this Agreement and the proposed purchase of the Stock, and the Company shall pay the full amount thereof to ▇▇ ▇▇▇▇▇ no later than 15 days from the date of demand. If this Agreement is terminated pursuant to Section 10 by reason of the default of one or more Underwriters, the Company shall not be obligated to reimburse any defaulting Underwriter on account of those expenses.

10. SUBSTITUTION OF UNDERWRITERS. If any Underwriter or Underwriters shall default in its or their obligations to purchase shares of Stock hereunder and the aggregate number of shares which such defaulting Underwriter or Underwriters agreed but failed to purchase does not exceed ten percent (10%) of the total number of shares underwritten, the other Underwriters shall be obligated severally, in proportion to their respective commitments hereunder, to purchase the shares which such defaulting Underwriter or Underwriters agreed but failed to purchase. If any Underwriter or Underwriters shall so default and the aggregate number of shares with respect to which such default or defaults occur is more than ten percent (10%) of the total number of shares underwritten and arrangements satisfactory to the Representatives and the Company for the purchase of such shares by

other persons are not made within forty-eight (48) hours after such default, this Agreement shall terminate.

If the remaining Underwriters or substituted Underwriters are required hereby or agree to take up all or part of the shares of Stock of a defaulting Underwriter or Underwriters as provided in this Section 10, (i) the Company shall have the right to postpone the Closing Dates for a period of not more than five (5) full business days in order that the Company may effect whatever changes may thereby be made necessary in the Registration Statement or the Prospectus, or in any other documents or arrangements, and the Company agrees promptly to file any amendments to the Registration Statement or supplements to the Prospectus which may thereby be made necessary, and (ii) the respective numbers of shares to be purchased by the remaining Underwriters or substituted Underwriters shall be taken as the basis of their underwriting obligation for all purposes of this Agreement. Nothing herein contained shall relieve any defaulting Underwriter of its liability to the Company or the other Underwriters for damages occasioned by its default hereunder. Any termination of this Agreement pursuant to this Section 10 shall be without liability on the part of any non-defaulting Underwriter or the Company, except expenses to be paid or reimbursed pursuant to Sections 5 and 9 and except the provisions of Section 7 shall not terminate and shall remain in effect.

11. SUCCESSORS; PERSONS ENTITLED TO BENEFIT OF AGREEMENT. This Agreement shall inure to the benefit of and be binding upon the several Underwriters, the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person other than the persons mentioned in the preceding sentence any legal or equitable right, remedy or claim under or in respect of this Agreement, or any provisions herein contained, this Agreement and all conditions and provisions hereof being intended to be and being for the sole and exclusive benefit of such persons and for the benefit of no other person; except that the representations, warranties, covenants, agreements and indemnities of the Company contained in this Agreement shall also be for the benefit of the Underwriter Indemnified Parties, and the indemnities of the several Underwriters shall also be for the benefit of the Company Indemnified Parties. It is understood that the Underwriters' responsibility to the Company is solely contractual in nature and the Underwriters do not owe the Company, or any other party, any fiduciary duty as a result of this Agreement.

12. SURVIVAL OF INDEMNITIES, REPRESENTATIONS, WARRANTIES, ETC. The respective indemnities, covenants, agreements, representations, warranties and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by them respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation made by or on behalf of any Underwriter, the Company or any person controlling any of them and shall survive delivery of and payment for the Stock.

13. NOTICES. All statements, requests, notices and agreements hereunder shall be in writing, and:

(a) if to the Underwriters, shall be delivered or sent by mail to:

▇▇ ▇▇▇▇▇ & Co., LLC
▇▇▇▇ ▇▇▇▇▇▇ ▇▇ ▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇
Attention: Equity Capital Markets Department

with copies to:

▇▇ ▇▇▇▇▇ & Co., LLC
▇▇▇▇ ▇▇▇▇▇▇ ▇▇ ▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇
Attention: Legal and Compliance Department

(b) if to the Company shall be delivered or sent by mail, telex or facsimile transmission to Metabasis Therapeutics, Inc., ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇ ▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇ ▇▇▇▇▇, Attention: Chief Executive Officer (Fax: (▇▇▇) ▇▇▇-▇▇▇▇).

14. DEFINITION OF CERTAIN TERMS. For purposes of this Agreement, (a) "business day" means any day on which the New York Stock Exchange, Inc. is open for trading and (b) "subsidiary" has the meaning set forth in Rule 405 of the Rules and Regulations.

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

16. UNDERWRITERS' INFORMATION. The parties hereto acknowledge and agree that, for all purposes of this Agreement, the Underwriters' Information consists solely of the following information in the Prospectus: (i) the statements on the front cover page concerning the terms of the offering by the Underwriters; and (ii) the statements concerning the Underwriters contained in the third paragraph (concerning the terms of the offering) and the tenth paragraph (concerning short sales and stabilizing transactions) and the table of Underwriters participating in the offering under the heading "Underwriting."

17. AUTHORITY OF THE REPRESENTATIVES. In connection with this Agreement, you will act for and on behalf of the several Underwriters, and any action taken under this Agreement by the Representatives will be binding on all the Underwriters.

18. PARTIAL UNENFORCEABILITY. The invalidity or unenforceability of any Section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other Section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

19. GENERAL. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. In this Agreement, the masculine, feminine and neuter genders and the singular and the plural include one another. The section headings in this Agreement are for the convenience of the parties only and will not affect the construction or interpretation of this Agreement. This Agreement may be amended or modified, and the observance of any term of this Agreement may be waived, only by a writing signed by the Company and the Representatives.

20. COUNTERPARTS. This Agreement may be signed in any number of counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

If the foregoing is in accordance with your understanding of the agreement between the Company and the several Underwriters, kindly indicate your acceptance in the space provided for that purpose below.

		Very truly yours,
		METABASIS THERAPEUTICS, INC.
		By:	Name: Title:
Accepted as of the date first above written:
▇▇ ▇▇▇▇▇ & CO., LLC DEUTSCHE BANK SECURITIES INC. ▇▇▇▇▇▇ ▇▇▇▇▇▇ PARTNERS LLC ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, INCORPORATED Acting on their own behalf and as Representatives of the several Underwriters referred to in the foregoing Agreement.
By:	▇▇ ▇▇▇▇▇ & CO., LLC
By:	Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇, ▇▇. Title: Head of Equity Capital Markets

SCHEDULE A

Name		Number of Firm Shares to be Purchased		Number of Optional Shares to be Purchased
▇▇ ▇▇▇▇▇ & Co., LLC

Deutsche Bank Securities Inc.

▇▇▇▇▇▇ ▇▇▇▇▇▇ Partners LLC

▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, Incorporated

[Other Underwriters]

Total

SCHEDULE B

List of Stockholders Subject to Section 4(h)

Executive Officers and Directors:
    ▇▇▇▇ ▇. ▇▇▇▇▇▇▇, Ph.D.
    ▇▇▇▇ ▇. ▇▇▇▇▇, Ph.D.
    ▇▇▇▇ ▇. ▇▇▇▇, C.P.A.
    ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, Ph.D., M.B.A.
    ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
    ▇▇▇▇ ▇. ▇▇▇▇▇, Ph.▇.
    ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇, Ph.D.
    ▇▇▇▇▇ ▇. ▇▇▇▇
    ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇, Ph.D.

5% Stockholders:
    Funds affiliated with MPM Capital L.P.
    Funds affiliated with InterWest Management Partners VII, LLC
    Sicor Inc.
    Funds affiliated with Sprout Capital IX, L.P.
    Funds affiliated with Maverick Capital, Ltd.

Other Stockholders:
Other stockholders holding, together with the stockholders above, 99.5% of the fully-
diluted shares of Common Stock outstanding on the date hereof

Exhibit I

Form of Lock-Up Agreement

January 26, 2004

▇▇ ▇▇▇▇▇ Securities Corporation
Deutsche Bank Securities Inc. ▇▇▇▇▇▇ ▇▇▇▇▇▇ Partners LLC
▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, Incorporated
As representatives of the
several Underwriters
c/o ▇▇ ▇▇▇▇▇ Securities Corporation
▇▇▇▇ ▇▇▇▇▇▇ ▇▇ ▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Re:: Metabasis Therapeutics, Inc. Shares of Common Stock

Dear Sirs:

In order to induce ▇▇ ▇▇▇▇▇ Securities Corporation ("▇▇ ▇▇▇▇▇") and Deutsche Bank Securities Inc., ▇▇▇▇▇▇ ▇▇▇▇▇▇ Partners LLC and ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, Incorporated to enter into a certain underwriting agreement (the "Underwriting Agreement") with Metabasis Therapeutics, Inc., a Delaware corporation (the "Company"), with respect to the public offering of shares of the Company's Common Stock, par value $0.001 per share ("Common Stock"), the undersigned hereby agrees that for a period of 180 days following the date of the final prospectus filed by the Company with the Securities and Exchange Commission in connection with such public offering, the undersigned will not, without the prior written consent of ▇▇ ▇▇▇▇▇, directly or indirectly, (i) offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of, any shares of Common Stock (including, without limitation, Common Stock which may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations promulgated under the Securities Act of 1933, as the same may be amended or supplemented from time to time (such shares, the "Beneficially Owned Shares")) or securities convertible into or exercisable or exchangeable in Common Stock, (ii) enter into any swap, hedge or similar agreement or arrangement that transfers in whole or in part, the economic risk of ownership of the Beneficially Owned Shares or securities convertible into or exercisable or exchangeable in Common Stock or (iii) engage in any short selling of the Common Stock. The foregoing sentence shall not apply to transactions relating to shares of Common Stock acquired in open market transactions by the undersigned after completion of such public offering.

Anything contained herein to the contrary notwithstanding, any person to whom shares of Common Stock or Beneficially Owned Shares are transferred from the undersigned shall be bound by the terms of this Agreement. In addition, anything contained herein to the contrary notwithstanding, the undersigned may transfer the undersigned's shares of Common Stock (i) as a bona fide gift or gifts, (ii) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned, (iii) if the undersigned is a corporation, to any wholly-owned subsidiary of such corporation, (iv) if the undersigned is a limited liability company, to a member or affiliated limited liability company or (v) if the undersigned is a partnership, to a partner or affiliated partnership; provided that in any such case, (A) it shall be a condition to the transfer that the donee or transferee execute an agreement stating that the donee or transferee is receiving and holding such capital stock subject to the provisions of this Lock-Up Agreement and there shall be no further transfer of such capital stock except in accordance with this agreement, (B) any such transfer shall not involve a disposition for value, (C) no filing by any party (donor, donee, transferor or transferee) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), shall be required or shall be voluntarily made in connection with such transfer (other than a filing on a Form 5, Schedule 13D or Schedule 13G made after the expiration of the 180-day period referred to above), (D) each party

(donor, donee, transferor or transferee) shall not be required by law (including without limitation the disclosure requirements of the Securities Act of 1933, as amended, and the Exchange Act) to make, and shall agree to not voluntarily make, any public announcement of the transfer or disposition, and (E) the undersigned notifies ▇▇ ▇▇▇▇▇ at least two business days prior to the proposed transfer or disposition. For purposes of this Lock-Up Agreement, "immediate family" shall mean any relationship by blood, marriage or adoption, not more remote than first cousin.

It is understood that, if the Company notifies you that it does not intend to proceed with the public offering, if the Underwriting Agreement does not become effective, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Common Stock to be sold in the public offering, the undersigned will be released from its obligations under this Lock-Up Agreement.

The undersigned acknowledges that Lock-Up Agreements in form and substance similar to this Lock-Up Agreement have been or will be delivered to you by other parties in connection with the proposed public offering, and that ▇▇ ▇▇▇▇▇, on behalf of the several Underwriters, may consent to any sale, transfer, disposition or other action otherwise prohibited under any such other Lock-Up Agreement without any obligation or liability to the undersigned.

In addition, the undersigned hereby waives, from the date hereof until the expiration of the 180 day period following the date of the Company's final Prospectus, any and all rights, if any, to request or demand registration pursuant to the Securities Act of any shares of Common Stock that are registered in the name of the undersigned or that are Beneficially Owned Shares. In order to enable the aforesaid covenants to be enforced, the undersigned hereby consents to the placing of legends and/or stop-transfer orders with the transfer agent of the Common Stock with respect to any shares of Common Stock or Beneficially Owned Shares.

		[Signatory]
		By:		Name: Title:

Exhibit II

Form of Opinion of Counsel to the Company

1.: The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Delaware, and, to our knowledge, is duly qualified to do business and is in good standing as a foreign corporation in each jurisdiction in which its ownership or lease of property or the conduct of its business requires such qualification, except to the extent the failure to so qualify or be in good standing would not reasonably be expected to have a material adverse effect on the general affairs, management, consolidated financial position, stockholders' equity, results of operations, business or prospects of the Company (a "Material Adverse Effect"), and has all corporate power and authority necessary to own or hold its properties and conduct its business as described in the Registration Statement and the Prospectus.
2.: The Company has an authorized capitalization as set forth in the Prospectus. All of the issued shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and non-assessable, and conform in all material respects to the description thereof contained in the Prospectus.
3.: The Shares have been duly and validly authorized and, when issued and delivered against payment therefor in accordance with the terms of the Underwriting Agreement, will be duly and validly issued, fully paid and non-assessable.
4.: To our knowledge, there are no preemptive or other rights to subscribe for or to purchase, nor any restriction upon the voting or transfer of, the Shares pursuant to the Company's charter or by-laws or any agreement or other instrument filed as an exhibit to the Registration Statement, other than preemptive or other rights to subscribe for or to purchase the Shares, voting or transfer restrictions on the Shares and other claims created by, or resulting from the actions of, the Underwriters.
5.: To our knowledge, there are no legal or governmental proceedings pending to which the Company is a party or of which any property or assets of the Company is the subject that are required to be described in the Registration Statement or the Prospectus and are not so described.
6.: The Registration Statement was declared effective under the Securities Act, any required filing of the Prospectus pursuant to Rule 424(b) of the Rules and Regulations has been made in the manner and within the time period required by Rule 424(b) of the Rules and Regulations and, to our knowledge, (i) no stop order suspending the effectiveness of the Registration Statement has been issued and (ii) no proceeding for that purpose is pending or threatened.
7.: The Registration Statement and the Prospectus (except for the financial statements and schedules and other financial and statistical data included therein, as to which we express no opinion) comply as to form in all material respects with the requirements of the Securities Act and the Rules and Regulations.
8.: The statements contained in the Prospectus under the caption "Description of Capital Stock," insofar as they purport to constitute a summary of the terms of the Common Stock, and under the caption "Material U.S. Federal Income Tax Consequences to Non-U.S. Holders," insofar as they purport to summarize certain provisions of the statutes or regulations referred to therein, are accurate in all material respects and present fairly the information required to be shown.
9.: To our knowledge, there are no contracts or other documents which are required to be described in the Prospectus or filed as exhibits to the Registration Statement by the Securities Act or by the Rules and Regulations which have not been described or filed as exhibits to the Registration Statement or incorporated therein by reference as permitted by the Rules and Regulations.
10.: The Underwriting Agreement has been duly authorized, executed and delivered by the Company.

11.: To our knowledge, the execution and delivery of the Underwriting Agreement by the Company and the issue and sale of the Shares by the Company pursuant to the Underwriting Agreement will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument filed as an exhibit to the Registration Statement (except where such conflict, breach, violation or default would not reasonably be expected to have a Material Adverse Effect), nor will such actions result in any violation of the provisions of the charter or by-laws of the Company or any statute or any order, rule or regulation known to us of any court or governmental agency or body to be applicable to the Company or any of its properties or assets (except where such violation would not reasonably be expected to have a Material Adverse Effect); and, except for the registration of the Shares under the Securities Act and such consents, approvals, authorizations, registrations or qualifications as may be required under the Exchange Act and applicable state or foreign securities laws in connection with the purchase and distribution of the Shares by the Underwriters, no consent, approval, authorization or order of, or filing or registration with, any such court or governmental agency or body is required for the execution and delivery of the Underwriting Agreement by the Company and the issue and sale of the Shares by the Company pursuant to the Underwriting Agreement, except for such consents, approvals, authorizations, orders, filings or registrations as have been obtained or made.
12.: To our knowledge and except as set forth in the Prospectus, there are no contracts, agreements or understandings filed as an exhibit to the Registration Statement between the Company and any person granting such person the right (other than rights which have been waived or satisfied) to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to the Registration Statement or in any securities being currently registered pursuant to any other registration statement filed by the Company under the Securities Act.
13.: The Company is not and, after giving effect to the offering and sale of the Shares and the application of the net proceeds therefrom as set forth in the Prospectus, will not be subject to registration as an "investment company" within the meaning of such term under the Investment Company Act and the rules and regulations of the Commission promulgated thereunder.

* * *

In the course of the preparation of the Registration Statement and Prospectus, we have participated in conferences with officers and other representatives of the Company, representatives of the independent public accountants of the Company and representatives of the Underwriters and their legal counsel at which the contents of the Registration Statement and the Prospectus were discussed and, although we have not independently verified and are not passing upon and do not assume responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement or the Prospectus (except as and to the extent stated in paragraph 8 above), on the basis of the foregoing nothing has come to our attention that causes us to believe that (A) the Registration Statement (except for the financial statements and schedules and other financial and statistical data included therein, as to which we express no belief), at the time the Registration Statement became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, or (B) the Prospectus (except for the financial statements and schedules and other financial and statistical data included therein, as to which we express no belief), as of the date of the Prospectus, or as of the date hereof, 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, in light of the circumstances under which they were made, not misleading.

Exhibit III

Form of Opinion of Intellectual Property Counsel to the Company

1.: As to the statements in the Prospectus under the captions "Risk Factors—Risks Related to our Intellectual Property" and "Business—Intellectual Property," in each case, insofar as such statements relate to United States patents and United States Patent Applications and constitute matters of United States patent laws or legal conclusions with respect thereto, such statements fairly summarize the matters referred to therein, in each case, in all material respects.
2.: As to those United States patents and United States patent applications that we have prosecuted on behalf of the Company, the Company is listed in the records of the United States Patent and Trademark Office as the owner of record of such of the Company's patents and patent applications. Schedule A is a list of the United States patents and United States patent applications that we have prosecuted on behalf of the Company. To our knowledge, there is no pending or threatened suit, proceeding or claim challenging the validity or scope of any of the Company's patents or patent applications. To our knowledge, the Company is the owner of all patent rights described as owned in the Prospectus. To our knowledge, the Company has taken such steps as are required, including the payment of all necessary maintenance fees, to maintain the enforceability of the issued United States patents listed on Schedule B, and to maintain the pendency of the foreign patents and foreign patent applications listed on Schedule C.

In connection with the preparation of the Registration Statement and the Prospectus, we have participated in conferences with directors, officers, and/or other representatives of the Company and counsel for the Underwriters at which the contents of the Registration Statement and Prospectus were discussed and, although we have not independently verified and are not passing upon and do not assume responsibility, explicitly or implicitly, for the accuracy, completeness or fairness of the statements contained in the Registration Statement or Prospectus (except as to the extent stated, but only to the extent expressly stated, in paragraph 1 set forth above), on the basis of the foregoing, solely with respect to those portions of the Prospectus related to the Company's patents and patent applications, no facts have come to our attention which caused us to believe that the Registration Statement at the time such Registration Statement became effective contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, or that the Prospectus at the date of such Prospectus or at the date hereof 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, in light of the circumstances under which they were made, not misleading.

QuickLinks

Exhibit 1.1

UNDERWRITING AGREEMENT
SCHEDULE A
SCHEDULE B List of Stockholders Subject to Section 4(h)
Exhibit I Form of Lock-Up Agreement
Exhibit II Form of Opinion of Counsel to the Company
Exhibit III Form of Opinion of Intellectual Property Counsel to the Company

Shares METABASIS THERAPEUTICS, INC. Common Stock UNDERWRITING AGREEMENT

Document Metadata

Document Metadata

Table of Contents