EXHIBIT 1.1 TOLERRX, INC. _____Shares(1) of Common Stock UNDERWRITING AGREEMENT ________________, 2003 J.P. Morgan Securities Inc. SG Cowen Securities Corporation Leerink Swann & Company, Inc. As Representatives of the several Underwriters listed in Schedule 1 hereto c/o J.P. Morgan Securities Inc. 277 Park Avenue New York, New York 10172 Ladies and Gentlemen: TolerRx, Inc., a Delaware corporation (the "COMPANY"), proposes to issue and sell to the several Underwriters listed in Schedule 1 hereto (the "UNDERWRITERS"), for whom you are acting as representatives (the "REPRESENTATIVES"), an aggregate of _______ shares of common stock, par value $.001 per share ("COMMON STOCK"), of the Company (the "UNDERWRITTEN SHARES") and, at the option of the Underwriters, up to an additional ________ shares of Common Stock of the Company (the "OPTION SHARES"). The Underwritten Shares and the Option Shares are herein referred to as the "SHARES". The shares of Common Stock of the Company to be outstanding after giving effect to the sale of the Shares are herein referred to as the "STOCK". As part of the offering contemplated by this Agreement, SG Cowen Securities Corporation (the "Designated Underwriter") has agreed to reserve out of the Underwritten Shares purchased by it under this Agreement, up to [___] shares, for sale to the Company's [customers and business partners and friends and family 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 Underwritten Shares 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. The Company hereby confirms its agreement with the several Underwriters concerning the purchase and sale of the Shares, as follows: 1. REGISTRATION STATEMENT. The Company has prepared and filed with the Securities and Exchange Commission (the "COMMISSION") under the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the "SECURITIES ACT"), a registration statement (Reg No. 333-108244) including a prospectus, relating to the Shares. Such - -------- 1 Plus an option to purchase from the Company up to an additional _______ shares to cover over-allotments. registration statement, as amended at the time it becomes effective, including the information, if any, deemed pursuant to Rule 430A under the Securities Act to be part of the registration statement at the time of its effectiveness ("RULE 430A INFORMATION"), is referred to herein as the "REGISTRATION STATEMENT"; and as used herein, the term "PRELIMINARY PROSPECTUS" means each prospectus included in such registration statement (and any amendments thereto) before it becomes effective, any prospectus filed with the Commission pursuant to Rule 424(a) under the Securities Act and the prospectus included in the Registration Statement at the time of its effectiveness that omits Rule 430A Information, and the term "PROSPECTUS" means the prospectus in the form first used to confirm sales of the Shares. If the Company has filed an abbreviated registration statement pursuant to Rule 462(b) under the Securities Act (the "RULE 462 REGISTRATION STATEMENT"), then any reference herein to the term "REGISTRATION STATEMENT" shall be deemed to include such Rule 462 Registration Statement. 2. PURCHASE OF THE SHARES BY THE UNDERWRITERS. (a) The Company agrees, subject to and upon the terms and conditions set forth in this Agreement, to issue and sell the Shares to the several Underwriters as provided in this Agreement, and each Underwriter, on the basis of the representations, warranties and agreements set forth herein and subject to the terms and conditions set forth herein, agrees, severally and not jointly, to purchase from the Company the respective number of Underwritten Shares set forth opposite such Underwriter's name in Schedule 1 hereto at a price per share (the "PURCHASE PRICE") of $________. In addition, the Company agrees, subject to and upon the terms and conditions set forth in this Agreement, to issue and sell the Option Shares to the several Underwriters as provided in this Agreement, and the Underwriters, on the basis of the representations, warranties and agreements set forth herein and subject to the terms and conditions set forth herein, shall have the option to purchase, severally and not jointly, from the Company the Option Shares at the Purchase Price. If any Option Shares are to be purchased, the number of Option Shares to be purchased by each Underwriter shall be the number of Option Shares which bears the same ratio to the aggregate number of Option Shares being purchased as the number of Underwritten Shares set forth opposite the name of such Underwriter in Schedule 1 hereto (or such number increased as set forth in Section 9 hereof) bears to the aggregate number of Underwritten Shares being purchased from the Company by the several Underwriters, subject, however, to such adjustments to eliminate any fractional Shares as the Representatives in their sole discretion shall make. The Underwriters may exercise the option to purchase the Option Shares at any time in whole, or from time to time in part, on or before the thirtieth day following the date of this Agreement, by written notice from the Representatives to the Company. Such notice shall set forth the aggregate number of Option Shares as to which the option is being exercised and the date and time when the Option Shares are to be delivered and paid for which may be the same date and time as the Closing Date (as hereinafter defined) but shall not be earlier than the Closing Date nor later than the tenth full business day (as hereinafter defined) after the date of such notice (unless such time and date are postponed in accordance with the provisions of Section 9 hereof). Any such notice shall be given at least two business days prior to the date and time of delivery specified therein. 2 (b) The Company understands that the Underwriters intend to make a public offering of the Shares as soon after the effectiveness of this Agreement as in the judgment of the Representatives is advisable, and initially to offer the Shares on the terms set forth in the Prospectus. The Company acknowledges and agrees that the Underwriters may offer and sell Shares to or through any affiliate of an Underwriter and that any such affiliate may offer and sell Shares purchased by it to or through any Underwriter. (c) The terms of the initial public offering by the Underwriters of the Shares to be purchased by them shall be as set forth in the Prospectus. The Underwriters may from time to time change the public offering price after the closing of the initial public offering and increase or decrease the concessions and discounts to dealers as they may determine. (d) Payment for the Shares shall be made by wire transfer in immediately available funds to the account specified by the Company to the Representatives in the case of the Underwritten Shares, at the offices of Morgan, Lewis & Bockius LLP, 101 Park Avenue, New York, New York 10178 at 10:00 A.M., New York City time, on _____, 2003, or at such other time or place on the same or such other date, not later than the fifth business day thereafter, as the Representatives and the Company may agree upon in writing or, in the case of the Option Shares, on the date and at the time and place specified by the Representatives in the written notice of the Underwriters' election to purchase such Option Shares. The time and date of such payment for the Underwritten Shares is referred to herein as the "CLOSING DATE" and the time and date for such payment for the Option Shares, if other than the Closing Date, are herein referred to as the "ADDITIONAL CLOSING DATE". Payment for the Shares to be purchased on the Closing Date or the Additional Closing Date, as the case may be, shall be made against delivery to the Representatives for the respective accounts of the several Underwriters of the Shares to be purchased on such date in definitive form registered in such names and in such denominations as the Representatives shall request in writing not later than two full business days prior to the Closing Date or the Additional Closing Date, as the case may be, with any transfer taxes payable in connection with the sale of the Shares duly paid by the Company. The certificates for the Shares will be made available for inspection and packaging by the Representatives at the office of J.P. Morgan Securities Inc. not later than 1:00 P.M., New York City time, on the business day prior to the Closing Date or the Additional Closing Date, as the case may be. 3. REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company represents and warrants to each Underwriter that: (a) PRELIMINARY PROSPECTUS. No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, complied in all material respects with the Securities Act and did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; PROVIDED that the Company makes - ------------------------- 2 Three business days (T+3) or, in the event the offering is priced after 4:30 P.M. Eastern Time, four business days after the date of the Underwriting Agreement. 3 no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in any Preliminary Prospectus. (b) REGISTRATION STATEMENT AND PROSPECTUS. The Registration Statement has been declared effective by the Commission. No order suspending the effectiveness of the Registration Statement has been issued by the Commission and no proceeding for that purpose has been initiated or threatened by the Commission; as of the applicable effective date of the Registration Statement and any amendment thereto, the Registration Statement complied and will comply in all material respects with the Securities Act, and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; and as of the applicable filing date of the Prospectus and any amendment or supplement thereto and as of the Closing Date and as of the Additional Closing Date, as the case may be, the Prospectus will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; PROVIDED that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in the Registration Statement and the Prospectus and any amendment or supplement thereto. (c) FINANCIAL STATEMENTS. The financial statements and the related notes thereto of the Company and its consolidated subsidiaries included in the Registration Statement and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the "EXCHANGE ACT"), as applicable, and present fairly the financial position of the Company and its subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis throughout the periods covered thereby, and the supporting schedules included in the Registration Statement present fairly the information required to be stated therein; the other financial information included in the Registration Statement and the Prospectus has been derived from the accounting records of the Company and its subsidiaries and presents fairly the information shown thereby; and the PRO FORMA financial information and the related notes thereto included in the Registration Statement and the Prospectus has been prepared in accordance with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and the assumptions underlying such PRO FORMA financial information are reasonable and are set forth in the Registration Statement and the Prospectus. Such PRO FORMA adjustments have been properly applied to the historical amounts in the compilation of the information and such information fairly presents, with respect to such entities, the financial position, results of operations and other information purported to be shown therein at the respective dates and for the respective periods specified. (d) NO MATERIAL ADVERSE CHANGE. Since the date of the most recent financial statements of the Company included in the Registration Statement and the Prospectus, (i) there 4 has not been any change in the capital stock (except any changes relating to the granting or exercise of stock options or equity awards pursuant to the Company's 2000 Equity Incentive Plan, as amended (the "EIP") or 2003 Employee Stock Purchase Plan, as amended (the "ESPP") or increase in long-term debt of the Company or any of its subsidiaries, or any dividend or distribution of any kind declared, set aside for payment, paid or made by the Company on any class of capital stock, or any material adverse change, or any development that would reasonably be expected to cause a prospective material adverse change, in or affecting the business, properties, management, financial position, stockholders' equity, results of operations, earnings or prospects of the Company and its subsidiaries taken as a whole; (ii) neither the Company nor any of its subsidiaries has entered into any transaction or agreement that is material to the Company and its subsidiaries taken as a whole or incurred any liability or obligation, direct or contingent, that is material to the Company and its subsidiaries taken as a whole; and (iii) neither the Company nor any of its subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in the Registration Statement and the Prospectus. (e) ORGANIZATION AND GOOD STANDING. The Company and each of its subsidiaries have been duly organized and are validly existing and in good standing under the laws of their respective jurisdictions of organization, are duly qualified to do business and are in good standing 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 be so qualified or have such power or authority would not, individually or in the aggregate, have a material adverse effect on the business, properties, management, financial position, stockholders' equity, results of operations, earnings or prospects of the Company and its subsidiaries taken as a whole (a "MATERIAL ADVERSE EFFECT"). The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the subsidiary listed in Exhibit 21.1 to the Registration Statement. (f) CAPITALIZATION. The Company has an authorized capitalization as set forth in the Prospectus under the heading "Capitalization"; all the outstanding shares of capital stock of the Company have been duly and validly authorized and issued and are fully paid and non-assessable and are not subject to any pre-emptive or similar rights; except as described in or expressly contemplated by the Prospectus, there are no outstanding rights (including, without limitation, pre-emptive rights), warrants or options to acquire, or instruments convertible into or exchangeable for, any shares of capital stock or other equity interest in the Company or any of its subsidiaries, or any contract, commitment, agreement, understanding or arrangement of any kind relating to the issuance of any capital stock of the Company or any such subsidiary, any such convertible or exchangeable securities or any such rights, warrants or options; the capital stock of the Company conforms in all material respects to the description thereof contained in the Registration Statement and the Prospectus; and all the outstanding shares of capital stock or other equity interests of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, 5 free and clear of any lien, charge, encumbrance, security interest, restriction on voting or transfer or any other claim of any third party. (g) DUE AUTHORIZATION. The Company has full right, power and authority to execute and deliver this Agreement and to perform its obligations hereunder; and all action required to be taken for the due and proper authorization, execution and delivery of this Agreement and the consummation of the transactions contemplated thereby has been duly and validly taken. (h) UNDERWRITING AGREEMENT. This Agreement has been duly authorized, executed and delivered by the Company and is a valid and binding agreement of the Company, enforceable in accordance with its terms, except as rights to indemnification hereunder may be limited by applicable law and except as the enforcement hereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles. (i) THE SHARES. The Shares have been duly and validly authorized by the Company and, when issued and delivered and paid for as provided herein, will be duly and validly issued and will be fully paid and nonassessable and will conform to the descriptions thereof in the Prospectus; and the issuance of the Shares is not subject to any preemptive or similar rights. (j) NO VIOLATION OR DEFAULT. Neither the Company nor any of its subsidiaries is (i) in violation of its charter or by-laws or similar organizational documents; (ii) in default, and no event has occurred that, 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 the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject; or (iii) in violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, including, without limitation, the United States Food and Drug Administration (the "FDA") or any comparable foreign, federal, state or local authority performing similar functions, except, in the case of clauses (ii) and (iii) above, for any such default or violation that would not, individually or in the aggregate, have a Material Adverse Effect. (k) NO CONFLICTS. The execution, delivery and performance by the Company of this Agreement, the issuance and sale of the Shares and the consummation of the transactions contemplated by this Agreement 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, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of its subsidiaries pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject; (ii) result in any violation of the provisions of the charter or by-laws or similar organizational documents of the Company or any of its subsidiaries; or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except, in the case of clauses (i) 6 and (iii) above, for any such conflict, breach or violation that would not, individually or in the aggregate, have a Material Adverse Effect. (l) NO CONSENTS REQUIRED. No consent, approval, authorization, order, registration or qualification of or with any court or arbitrator or governmental or regulatory authority is required for the execution, delivery and performance by the Company of this Agreement, the issuance and sale of the Shares and the consummation of the transactions contemplated by this Agreement, except for the registration of the Shares under the Securities Act and such consents, approvals, authorizations, orders and registrations or qualifications as may be required under applicable state securities laws in connection with the purchase and distribution of the Shares by the Underwriters. (m) LEGAL PROCEEDINGS. Except as described in the Prospectus, there are no legal, governmental or regulatory investigations, actions, suits or proceedings pending to which the Company or any of its subsidiaries is or may be a party or to which any property of the Company or any of its subsidiaries is or may be the subject that, individually or in the aggregate, if determined adversely to the Company or any of its subsidiaries, could reasonably be expected to have a Material Adverse Effect or materially and adversely affect the ability of the Company to perform its obligations under this Agreement; no such investigations, actions, suits or proceedings are threatened or, to the best knowledge of the Company, contemplated by any governmental or regulatory authority or threatened by others; and (i) there are no current or pending legal, governmental or regulatory actions, suits or proceedings that are required under the Securities Act to be described in the Prospectus that are not so described and (ii) there are no statutes, regulations or contracts or other documents that are required under the Securities Act to be filed as exhibits to the Registration Statement or described in the Registration Statement or the Prospectus that are not so filed or described. (n) INDEPENDENT ACCOUNTANTS. PricewaterhouseCoopers LLP, who have certified certain financial statements of the Company and its subsidiaries and delivered their report with respect to the consolidated financial statements and schedules included in the Prospectus are independent public accountants with respect to the Company and its subsidiaries, as required by the Securities Act and, to the knowledge of the Company, such accountants are in compliance with the auditor independence requirements of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith (the "SARBANES-OXLEY ACT"). (o) TITLE TO REAL AND PERSONAL PROPERTY. The Company and its subsidiaries own no real property and have good and marketable title to all personal property owned by them which is material to the business of the Company and its subsidiaries, or have valid, subsisting and enforceable rights to lease or otherwise use, all items of real and personal property that are material to the business of the Company and its subsidiaries, in each case free and clear of all liens, encumbrances, claims and defects and imperfections of title except those that (i) do not materially interfere with the use made and proposed to be made of such property by the Company and its subsidiaries or (ii) could not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. (p) INTELLECTUAL PROPERTY. The Company and its subsidiaries own or possess adequate rights to use all material patents, patent applications, trademarks, service marks, trade names, 7 trademark registrations, service mark registrations, copyrights, inventions, licenses and know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) ("INTELLECTUAL PROPERTY Rights") necessary for the conduct of their respective businesses, except to the extent disclosed in the Registration Statement or the Prospectus. Without limiting the generality of the foregoing, there are no limitations with respect to the Company's Intellectual Property Rights not described in the Prospectus that would prevent it from (a) performing its obligations under the Collaboration Agreement, dated December 23, 2002, between Genentech, Inc. and the Company (the "GENENTECH AGREEMENT"), and (b) engaging in activities contemplated by the Genentech Agreement, as described in the Prospectus. Except to the extent disclosed in the Registration Statement or the Prospectus, the conduct of business of the Company and its subsidiaries will not conflict in any material respect with any Intellectual Property Rights of others, and the Company and its subsidiaries have not received any notice of any claim of infringement or conflict with any such rights of others. The Company has taken usual and customary measures for a company of its size and resources and in its line of business to protect the secrecy, confidentiality and value of all of its Intellectual Property Rights in all material respects. (q) NO UNDISCLOSED RELATIONSHIPS. No relationship, direct or indirect, exists between or among the Company or any of its subsidiaries, on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company or any of its subsidiaries, on the other hand, that is required by the Securities Act to be described in the Registration Statement and the Prospectus and that is not so described. (r) INVESTMENT COMPANY ACT. The Company is not and, after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in the Prospectus, will not be required to register as an "investment company" or an entity "controlled" by an "investment company" within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder. (s) TAXES. The Company and its subsidiaries have paid all federal, state, local and foreign taxes and filed all tax returns required to be paid or filed through the date hereof; and except as otherwise disclosed in the Prospectus, there is no tax deficiency that has been, or could reasonably be expected to be, asserted against the Company or any of its subsidiaries or any of their respective properties or assets which would reasonably be expected to have a Material Adverse Effect. (t) LICENSES AND PERMITS. The Company and its subsidiaries possess all licenses, certificates, certifications, permits, consents, approvals and other authorizations issued by, and have made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of their respective properties or the conduct of their respective businesses as described in the Registration Statement and the Prospectus, except where the failure to possess or make the same would not, individually or in the aggregate, have a Material Adverse Effect; and except as described in the Prospectus, neither the Company nor any of its subsidiaries has received notice of any revocation or modification of any such license, certificate, permit, consent, approval or authorization or has any reason to believe that any such license, certificate, certification, permit or authorization will not be renewed in the ordinary course, and no proceeding or administrative 8 action has been instituted or is pending or is contemplated or threatened, which in any manner affects or draws into question the validity or effectiveness thereof. (u) REGULATORY SUBMISSIONS. Neither the Company nor any of its subsidiaries has failed to file with the applicable regulatory authorities (including, without limitation, the FDA or any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) any filing, declaration, listing, registration, report or submission which is required to be filed. All such filings, declarations, listings, registrations, reports or submissions were in compliance in all material respects with applicable laws when filed and no deficiencies have been asserted against the Company by any applicable regulatory authority (including, without limitation, the FDA or any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) with respect to any such filings, declarations, listings, registrations, reports or submissions. (v) NON-CLINICAL AND CLINICAL STUDIES. The non-clinical and clinical studies and tests (including, but without limitation, the animal studies and human clinical trials) conducted by the Company or in which the Company has participated and, to the Company's knowledge, such studies and tests that were conducted for or on behalf of the Company were and, if still pending, are being conducted in all material respects (i) in accordance with the protocols, procedures and controls for such studies and tests of drug or biologic products, as the case may be, and (ii) in accordance with all applicable laws, rules and regulations, including, without limitation, administered by the FDA. The descriptions of the results of such studies and tests contained in the Registration Statement and Prospectus are accurate, complete and fairly present the published data described, and the Company has no knowledge of any other studies or tests, the results of which call into question in any material respect the results described or referred to in the Registration Statement and Prospectus. The Company has not received any notices or correspondence from the FDA, any other U.S. or foreign, federal, state, local or other governmental agency, Institutional Review Board or Ethics Board requiring the termination, suspension or modification of any studies or tests conducted by, or on behalf of, the Company or in which the Company has participated that are described in the Registration Statement and Prospectus or the results of which are referred to in the Registration Statement and Prospectus that would cause the Company to change the descriptions in the Registration Statement or Prospectus. (w) NO LABOR DISPUTES. No labor disturbance by or dispute with employees of the Company or any of its subsidiaries exists or, to the knowledge of the Company, is contemplated or threatened; and the Company is not aware of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that could, individually or in the aggregate, have a Material Adverse Effect. (x) COMPLIANCE WITH ENVIRONMENTAL AND OCCUPATIONAL LAWS. Without limiting the generality of (j) and (t) above, each of the Company and its subsidiaries: (i) is in material compliance with any and all applicable foreign, federal, state and local laws, rules, regulations, treaties, statutes and codes promulgated by any and all governmental authorities relating to the protection of human health and safety, the environment or toxic substances or wastes, pollutants or contaminates ("ENVIRONMENTAL LAWS"); (ii) is in material compliance with any and all applicable foreign, federal, state and local laws, rules, regulations, treaties, statutes and codes 9 promulgated by any and all governmental authorities (including pursuant to the Occupational Health and Safety Act) relating to the protection of human health and safety in the workplace ("OCCUPATIONAL LAWS" and, together with Environmental Laws, "ENVIRONMENTAL AND OCCUPATIONAL LAWS"); (iii) has received all material permits, licenses or other approvals required of it under applicable Environmental and Occupational Laws to conduct its business as currently conducted; and (iv) is in compliance with all terms and conditions of such permit, license or approval, except with respect to all such cases where such noncompliance with the applicable Environmental and Occupational Laws or failure to receive or act in compliance with the required permit, license or other approval would not, individually or in the aggregate, have a Material Adverse Effect. No action, proceeding, revocation proceeding, writ, injunction or claim is pending or, to the Company's knowledge, threatened against the Company relating to Environmental and Occupational Laws or to the Company's activities involving Hazardous Materials. The term "HAZARDOUS MATERIALS" as used in this Agreement means any material or substance that: (A) is prohibited or regulated by any environmental law, rule, regulation, order, treaty, statute or code promulgated by any governmental authority, or any amendment or modification thereto; or (B) has been designated or regulated by any governmental authority as radioactive, toxic, hazardous or otherwise a danger to health, reproduction or the environment. (y) HAZARDOUS MATERIALS. The Company is not or was not engaged in the generation, use, manufacture, transportation or storage of any Hazardous Materials on any of the Company's properties or former properties, except where such use, manufacture, transportation or storage is or was in material compliance with Environmental Laws. No Hazardous Materials have been treated or disposed of by the Company on any of the Company's properties or on properties formerly owned or leased by the Company during the time of such ownership or lease, except in compliance with Environmental Laws. To the Company's knowledge, no spills, discharges, releases, deposits, emplacements, leaks or disposal of any Hazardous Materials have occurred on or under, or have emanated from, any of the Company's properties or former properties for which the cost of remediation would have a Material Adverse Effect. (z) NO ENVIRONMENTAL COSTS. There are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, individually or in the aggregate, have a Material Adverse Effect. (aa) COMPLIANCE WITH ERISA. Each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended ("ERISA"), that is maintained, administered or contributed to by the Company or any of its affiliates for employees or former employees of the Company and its affiliates has been maintained in compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of 1986, as amended (the "CODE"); no prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, has occurred with respect to any such plan excluding transactions effected pursuant to a statutory or administrative exemption which could reasonably be expected to have a Material Adverse Effect; and for each such plan that is subject to the funding rules of Section 412 of the Code or Section 302 of ERISA, no "accumulated funding deficiency" as 10 defined in Section 412 of the Code has been incurred, whether or not waived, and the fair market value of the assets of each such plan (excluding for these purposes accrued but unpaid contributions) exceeds the present value of all benefits accrued under such plan determined using reasonable actuarial assumptions. (bb) ACCOUNTING CONTROLS. The Company and its subsidiaries maintain systems of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management's general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management's general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. (cc) INSURANCE. The Company and its subsidiaries have insurance covering their respective properties, operations, personnel and businesses, including business interruption insurance, which insurance is in amounts and insures against such losses and risks as are adequate to protect the Company and its subsidiaries and their respective businesses; and neither the Company nor any of its subsidiaries has (i) received notice from any insurer or agent of such insurer that capital improvements or other expenditures are required or necessary to be made in order to continue such insurance or (ii) any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage at reasonable cost from similar insurers as may be necessary to continue its business. (dd) NO UNLAWFUL PAYMENTS. Neither the Company nor any of its subsidiaries nor, to the best knowledge of the Company, any director, officer, agent, employee or other person associated with or acting on behalf of the Company or any of its subsidiaries has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; (iii) violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977; or (iv) made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment. (ee) NO RESTRICTIONS ON SUBSIDIARIES. No subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such subsidiary's capital stock, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary's properties or assets to the Company or any other subsidiary of the Company. (ff) NO BROKER'S FEES. Neither the Company nor any of its subsidiaries is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against the Company or any of its subsidiaries or any Underwriter for a brokerage commission, finder's fee or like payment in connection with the offering and sale of the Shares. 11 (gg) NO REGISTRATION RIGHTS. No person has the right to require the Company or any of its subsidiaries to register any securities for sale under the Securities Act by reason of the filing of the Registration Statement with the Commission or the issuance and sale of the Shares other than as described in the Registration Statement and as have been waived in writing in connection with the offering contemplated hereby. (hh) NO STABILIZATION. The Company has not taken, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares. (ii) FORWARD-LOOKING STATEMENTS. No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Registration Statement and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith. (jj) STATISTICAL AND MARKET DATA. Nothing has come to the attention of the Company that has caused the Company to believe that the statistical and market-related data included in the Registration Statement and the Prospectus is not based on or derived from sources that are reliable and accurate in all material respects. (kk) NASDAQ NATIONAL MARKET. The Shares to be sold by the Company have been approved for quotation by the National Association of Securities Dealers Automated Quotations National Market (the "NASDAQ NATIONAL MARKET"). (ll) THE GENENTECH AGREEMENT. The execution, delivery and performance by the Company of the Genentech Agreement was duly authorized and approved by all requisite corporate and other action on the part of the Company, and the consummation of this offering will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, such agreement. (mm) The Registration Statement, 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. (nn) The Company has not offered, or caused the Underwriters to offer, any Underwritten Shares 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. 12 4. FURTHER AGREEMENTS OF THE COMPANY. The Company covenants and agrees with each Underwriter that: (a) EFFECTIVENESS OF THE REGISTRATION STATEMENT. The Company has filed the final Prospectus with the Commission within the time periods specified by Rule 424(b) and Rule 430A under the Securities Act and the Company will furnish copies of the Prospectus to the Underwriters as soon as practicable after the Registration Statement becomes effective in such quantities as the Representatives may reasonably request. (b) DELIVERY OF COPIES. The Company will deliver, without charge, (i) to the Representatives four signed copies of the Registration Statement as originally filed and each amendment thereto, in each case including all exhibits and consents filed therewith; and (ii) to each Underwriter (A) a conformed copy of the Registration Statement as originally filed and each amendment thereto (without exhibits) and (B) during the Prospectus Delivery Period, as many copies of the Prospectus (including all amendments and supplements thereto) as the Representatives may reasonably request. As used herein, the term "Prospectus Delivery Period" means such period of time after the first date of the public offering of the Shares as in the opinion of counsel for the Underwriters a prospectus relating to the Shares is required by law to be delivered in connection with sales of the Shares by any Underwriter or dealer. (c) AMENDMENTS OR SUPPLEMENTS. Before filing any amendment or supplement to the Registration Statement or the Prospectus, the Company will furnish to the Representatives and counsel for the Underwriters a copy of the proposed amendment or supplement for review and will not file any such proposed amendment or supplement to which the Representatives reasonably object. (d) NOTICE TO THE REPRESENTATIVES. The Company will advise the Representatives promptly, and confirm such advice in writing, (i) when any amendment to the Registration Statement has been filed or becomes effective; (ii) when any supplement to the Prospectus or any amendment to the Prospectus has been filed; (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or the receipt of any comments from the Commission relating to the Registration Statement or any other request by the Commission for any additional information; (iv) of the issuance by the Commission of any order suspending the effectiveness of the Registration Statement or preventing or suspending the use of any Preliminary Prospectus or the Prospectus or the initiation or threatening of any proceeding for that purpose; (v) of the occurrence of any event within the Prospectus Delivery Period 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 a material fact necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading; and (vi) of the receipt by the Company of any notice with respect to any suspension of the qualification of the Shares for offer and sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and the Company will use its best efforts to prevent the issuance of any such order suspending the effectiveness of the Registration Statement, preventing or suspending the use of any Preliminary Prospectus or the Prospectus or suspending any such qualification of the Shares and, if any such order is issued, the Company will use best efforts to obtain as soon as possible the withdrawal thereof. (e) ONGOING COMPLIANCE OF THE PROSPECTUS. If during the Prospectus Delivery Period (i) any event shall occur or condition shall exist as a result of which the Prospectus as then 13 amended or supplemented would include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading or (ii) it is necessary to amend or supplement the Prospectus to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Prospectus as may be necessary so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, be misleading or so that the Prospectus will comply with law. (f) BLUE SKY COMPLIANCE. The Company will qualify the Shares for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Representatives shall reasonably request and will continue such qualifications in effect so long as required for distribution of the Shares; PROVIDED that the Company shall not be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction where it would not otherwise be required to so qualify, (ii) file any general consent to service of process in any such jurisdiction or (iii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject. (g) EARNING STATEMENT. The Company will make generally available to its security holders and the Representatives as soon as practicable an earning statement that satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 of the Commission promulgated thereunder covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the "effective date" (as defined in Rule 158) of the Registration Statement. (h) CLEAR MARKET. For a period of 180 days after the date of the initial public offering of the Shares, the Company will not (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any shares of Stock or any securities convertible into or exercisable or exchangeable for Stock or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Stock or such other securities, in cash or otherwise, without the prior written consent of the Representatives, other than (a) the Shares to be sold hereunder, (b) any shares of Stock of the Company issued upon the exercise of options granted under existing employee stock option plans, (c) any shares of Stock or options or other equity grants under the EIP or ESPP (including the registration of such shares on a Form S-8) and (d) any transfers that are permitted under the "lock-up" agreements delivered to the Underwriters pursuant to Section 5(m) hereof. (i) USE OF PROCEEDS. The Company will apply the net proceeds from the sale of the Shares as described in the Prospectus under the heading "Use of proceeds". 14 (j) NO STABILIZATION. The Company will not take, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares. (k) REPORTS. For a period of five years from the date hereof, the Company will furnish to the Representatives, as soon as they are available, copies of all reports or other communications (financial or other) furnished to holders of the Shares, and copies of any reports and financial statements furnished to or filed with the Commission or any national securities exchange or automatic quotation system, provided that such reports, communications or financial statements are not available to the Representatives on the website of the Commission. (l) FILINGS. The Company will file with the Commission such reports as may be required by Rule 463 under the Securities Act. (m) SARBANES-OXLEY CONTROLS AND PROCEDURES. For a period of 180 days after the Closing Date, the Company and its subsidiaries will maintain such controls and other procedures, including, without limitation, those required by Sections 302 and 906 of the Sarbanes-Oxley Act and the applicable regulations thereunder, that are reasonably designed to ensure that material information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified and required in the Commission's rules and forms, including, without limitation, controls and procedures reasonably designed to ensure that material information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the Company's management, including its Chief Executive Officer and its Principal Financial Officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure to ensure that material information relating to Company, including its subsidiaries, is made known to them by others within those entities. (n) SARBANES-OXLEY COMPLIANCE. For a period of 180 days after the Closing Date, the Company and its subsidiaries will comply and will use its best efforts to cause the Company's directors and officers in their capacities as such to comply, in all material respects, with all applicable provisions of the Sarbanes-Oxley Act. (o) In connection with the Directed Share Program, the Company will use reasonable efforts to ensure that the Directed Shares will be restricted to the extent required by the National Association of Securities Dealers, Inc. (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 to the extent such Directed Shares are not already under restrictions that comply with such NASD requirements or such NASD rules. 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. (p) The Company will comply with all 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. 15 5. CONDITIONS OF UNDERWRITERS' OBLIGATIONS. The obligation of each Underwriter to purchase the Underwritten Shares on the Closing Date or the Option Shares on the Additional Closing Date, as the case may be, as provided herein is subject to the performance by the Company of its covenants and other obligations hereunder and to the following additional conditions: (a) REGISTRATION COMPLIANCE; NO STOP ORDER. The Registration Statement (or if a post-effective amendment thereto is required to be filed under the Securities Act, such post-effective amendment) shall have become effective, and the Representatives shall have received notice thereof, not later than 5:00 P.M., New York City time, on the date hereof; no order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose shall be pending before or threatened by the Commission; the Prospectus shall have been timely filed with the Commission under the Securities Act and in accordance with Section 4(a) hereof; and all requests by the Commission for additional information shall have been complied with to the reasonable satisfaction of the Representatives. (b) REPRESENTATIONS AND WARRANTIES. The representations and warranties of the Company contained herein shall be true and correct on the date hereof and on and as of the Closing Date or the Additional Closing Date, as the case may be; and the statements of the Company and its officers made in any certificates delivered pursuant to this Agreement shall be true and correct on and as of the Closing Date or the Additional Closing Date, as the case may be. (c) NO NASD OBJECTION. The NASD shall have raised no unresolved objection to the fairness and reasonableness of the underwriting terms and arrangements. (d) NO MATERIAL ADVERSE CHANGE. Subsequent to the execution and delivery of this Agreement, no event or condition of a type described in Section 3(d) hereof shall have occurred or shall exist, which event or condition is not described in the Prospectus (as amended prior to the date of this Agreement) and the effect of which in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Shares on the Closing Date or the Additional Closing Date, as the case may be, on the terms and in the manner contemplated by this Agreement and the Prospectus. (e) OFFICER'S CERTIFICATE. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, a certificate of the chief financial officer or chief accounting officer of the Company and one additional senior executive officer of the Company who is reasonably satisfactory to the Representatives (i) confirming that such officers have carefully reviewed the Registration Statement and the Prospectus and, to the best knowledge of such officers, the representation set forth in Section 3(b) hereof is true and correct, (ii) confirming that the other representations and warranties of the Company in this Agreement are true and correct and that the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date and (iii) to the effect set forth in paragraphs (a) and (d) above. (f) COMFORT LETTERS. On the date of this Agreement and on the Closing Date or the Additional Closing Date, as the case may be, PricewaterhouseCoopers LLP shall have furnished 16 to the Representatives, at the request of the Company, letters, dated the respective dates of delivery thereof and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, containing statements and information of the type customarily included in accountants' "comfort letters" to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus; PROVIDED, that the letter delivered on the Closing Date or the Additional Closing Date, as the case may be, shall use a "cut-off" date no more than three business days prior to such Closing Date or such Additional Closing Date, as the case may be. (g) OPINION OF COUNSEL FOR THE COMPANY. Bingham McCutchen LLP, counsel for the Company, shall have furnished to the Representatives, at the request of the Company, their written opinion, dated the Closing Date or the Additional Closing Date, as the case may be, and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, in the form attached as ANNEX A hereto. (h) OPINION OF PATENT COUNSEL FOR THE COMPANY. Carella, Byrne, Bain, Gilfillian, Cecchi, Stewart & Olstein, patent counsel for the Company, shall have furnished to the Representatives, at the request of the Company, their written opinion, dated the Closing Date or the Additional Closing Date, as the case may be, and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, in the form attached as ANNEX B hereto. (i) OPINION OF COUNSEL FOR THE UNDERWRITERS. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, an opinion of Morgan, Lewis & Bockius LLP, counsel for the Underwriters, with respect to such matters as the Representatives may reasonably request. (j) NO LEGAL IMPEDIMENT TO ISSUANCE. No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any federal, state or foreign governmental or regulatory authority that would, as of the Closing Date or the Additional Closing Date, as the case may be, prevent the issuance or sale of the Shares; and no injunction or order of any federal, state or foreign court shall have been issued that would, as of the Closing Date or the Additional Closing Date, as the case may be, prevent the issuance or sale of the Shares. (k) GOOD STANDING. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, satisfactory evidence of the good standing of the Company and its subsidiaries in their respective jurisdictions of organization and their good standing as foreign entities in such other jurisdictions as the Company is required to be registered and the Representatives may reasonably request, in each case in writing or any standard form of telecommunication from the appropriate governmental authorities of such jurisdictions. (l) EXCHANGE LISTING. The Shares to be delivered on the Closing Date or Additional Closing Date, as the case may be, shall have been approved for listing on the Nasdaq National Market, subject to official notice of issuance. 17 (m) LOCK-UP AGREEMENTS. The "lock-up" agreements, each substantially in the form of EXHIBIT A hereto, between you and certain shareholders, officers and directors of the Company relating to sales and certain other dispositions of shares of Stock or certain other securities, delivered to you on or before the date hereof, shall be full force and effect on the Closing Date or Additional Closing Date, as the case may be. (n) ADDITIONAL DOCUMENTS. On or prior to the Closing Date or the Additional Closing Date, as the case may be, the Company shall have furnished to the Representatives such further certificates and documents as the Representatives may reasonably request. All opinions, letters, certificates and evidence 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. 6. INDEMNIFICATION AND CONTRIBUTION. (a) INDEMNIFICATION OF THE UNDERWRITERS. The Company and each of its subsidiaries, jointly and severally, agree to indemnify and hold harmless each Underwriter, its affiliates, directors, officers, employees, representatives, agents and each person, if any, who controls such Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, reasonable legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, or are caused by, any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus (or any amendment or supplement thereto) or any Preliminary Prospectus, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, except insofar as such losses, claims, damages or liabilities arise out of, or are based upon, or are caused by, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 6(c) below; provided, that with respect to any such untrue statement in or omission from any preliminary prospectus, the indemnity agreement contained in this paragraph (a) shall not insure to the benefit of any Underwriter, its affiliates, directors, officers, employees, representatives, agents or any person, if any, who controls such Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act to the extent that the sale to the person asserting any such loss, claim, damage or liability was an initial resale by such Underwriter and any such loss, claim, damage or liability of or with respect to such Underwriter results from the fact that both (i) to the extent required by applicable law, a copy of the Prospectus was not sent or given to such person at or prior to the written confirmation of the sale of such Shares to such person and (ii) the untrue statement in or omission from such preliminary prospectus was corrected in the Prospectus unless, in either case, such failure to deliver the Prospectus was a result of non-compliance by the Company with the provisions of Section 4 hereof. 18 (b) Indemnification of the Designated Underwriter. The Company and each of its subsidiaries, jointly and severally, agree to indemnify and hold harmless the Designated Underwriter, its affiliates, directors, officers, employees, representatives, agents and each person, if any, who controls such Designated Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, reasonable legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, or are caused by, (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 of 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 for which the Participant made a binding agreement 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. (c) INDEMNIFICATION OF THE COMPANY. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, its directors, its officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as the indemnity set forth in paragraph (a) above, but only with respect to any losses, claims, damages or liabilities (including without limitation, reasonable legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred) that arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to such Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in the Registration Statement and the Prospectus (or any amendment or supplement thereto) or any Preliminary Prospectus, it being understood and agreed upon that the only such information furnished by any Underwriter consists of the following information in the Prospectus furnished on behalf of each Underwriter: the selling concession and discount figures appearing in the sixth paragraph under the caption "Underwriting", the information contained in the seventh paragraph under the section "Underwriting" and the information contained in the eighth paragraph under the section "Underwriting". (d) NOTICE AND PROCEDURES. If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against any person in respect of which indemnification may be sought pursuant to either paragraph (a) or (b) above, such person (the "INDEMNIFIED Person") shall promptly notify the person against whom such indemnification may be sought (the "INDEMNIFYING PERSON") in writing; PROVIDED that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have under this Section 6 except to the extent that it has been materially prejudiced (through the forfeiture 19 of substantive rights or defenses) by such failure; and PROVIDED, FURTHER, that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have to an Indemnified Person otherwise than under this Section 6. If any such proceeding shall be brought or asserted against an Indemnified Person and it shall have notified the Indemnifying Person thereof, the Indemnifying Person shall retain counsel reasonably satisfactory to the Indemnified Person to represent the Indemnified Person, any others entitled to indemnification pursuant to this Section 6 that the Indemnifying Person may designate in such proceeding and the Indemnifying Person, to the extent relevant, and shall pay the fees and expenses of such counsel related to such proceeding, as incurred. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary; (ii) the Indemnifying Person has failed within a reasonable time to retain counsel reasonably satisfactory to the Indemnified Person; (iii) the Indemnified Person shall have reasonably concluded that there may be legal defenses available to it that are different from or in addition to those available to the Indemnifying Person and counsel then representing the Indemnifying Person refuses or chooses not to assert such defenses; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the Indemnifying Person and the Indemnified Person and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood and agreed that (A) the Indemnifying Person shall not, in connection with any proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such fees and expenses shall be paid or reimbursed as they are incurred and (B) to the extent that any Indemnified Person retains separate counsel for reasons set forth in clause (iii) in the prior sentence, the Indemnifying Person shall be responsible only for the reasonable fees and expenses of separate counsel relating to pursuing the defenses that were not asserted. Any such separate firm for any Underwriter, its affiliates, directors and officers and any control persons of such Underwriter shall be designated in writing by J.P. Morgan Securities Inc. and any such separate firm for the Company, its directors, its officers who signed the Registration Statement and any control persons of the Company shall be designated in writing by the Company. The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify each Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested that an Indemnifying Person reimburse the Indemnified Person for fees and expenses of counsel as contemplated by this paragraph, the Indemnifying Person shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by the Indemnifying Person of such request and (ii) the Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement. No Indemnifying Person shall, without the written consent of the Indemnified Person, effect any settlement of any pending or threatened proceeding in respect of which any Indemnified Person is or could have been a party and indemnification could have been sought hereunder by such Indemnified Person, unless such settlement (x) includes an unconditional release of such Indemnified Person, in form and substance reasonably satisfactory to such Indemnified Person, from all liability on claims that are the subject matter of such proceeding and (y) does not 20 include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any Indemnified Person. Notwithstanding anything contained herein to the contrary, if indemnity may be sought pursuant to Section 6(b) hereof in respect of such action or proceeding, then in addition to such separate firm for the Indemnified Person, the Indemnifying Person 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 for the defense of any losses, claims, damages and liabilities arising out of the Directed Share Program, 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. (e) CONTRIBUTION. If the indemnification provided for in paragraphs (a) and (b) above is unavailable to an Indemnified Person or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each Indemnifying Person under such paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall contribute to the amount paid or payable by such Indemnified Person as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriters, on the other hand, from the offering of the Shares or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) but also the relative fault of the Company, on the one hand, and the Underwriters, on the other hand, in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, 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 hand, shall be deemed to be in the same respective proportions as the net proceeds (before deducting expenses) received by the Company from the sale of the Shares and the total underwriting discounts and commissions received by the Underwriters in connection therewith, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate offering price of the Shares. The relative fault of the Company, on the one hand, and the Underwriters, on the other hand, 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 or by the Underwriters, and the parties' relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. (f) LIMITATION ON LIABILITY. The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 6 were determined by PRO RATA allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in paragraph (d) above. The amount paid or payable by an Indemnified Person as a result of the losses, claims, damages and liabilities referred to in paragraph (d) above shall be deemed to include, subject to the limitations set forth above, any legal or other expenses incurred by such Indemnified Person in connection with any such action or claim. Notwithstanding the provisions of this Section 6, in no event shall an Underwriter be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or 21 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 pursuant to this Section 6 are several in proportion to their respective purchase obligations hereunder and not joint. (g) NON-EXCLUSIVE REMEDIES. The remedies provided for in this Section 6 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any Indemnified Person at law or in equity. 7. EFFECTIVENESS OF AGREEMENT. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto. 8. TERMINATION. This Agreement may be terminated in the absolute discretion of the Representatives, by notice to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date or, in the case of the Option Shares, prior to the Additional Closing Date (i) trading generally shall have been suspended or materially limited on or by any of the New York Stock Exchange, the American Stock Exchange, the NASD, the Chicago Board Options Exchange, the Chicago Mercantile Exchange or the Chicago Board of Trade; (ii) trading of any securities issued or guaranteed by the Company shall have been suspended on any exchange or in any over-the-counter market; (iii) a general moratorium on commercial banking activities shall have been declared by federal or New York State authorities; (iv) there shall have occurred any outbreak or escalation of hostilities or any change in financial markets or any calamity or crisis, either within or outside the United States, that, in the judgment of the Representatives, which in each case is material and adverse and makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Shares on the Closing Date or the Additional Closing Date, as the case may be, on the terms and in the manner contemplated by this Agreement and the Prospectus; or (v) there shall be any failure or refusal on the part of the Company to comply with the terms or to fulfill any of the conditions of this Agreement or the Company shall for any reason be unable to perform its obligations under this Agreement, in each case which the Underwriters have not waived. 9. DEFAULTING UNDERWRITER. (a) If, on the Closing Date or the Additional Closing Date, as the case may be, any Underwriter defaults on its obligation to purchase the Shares that it has agreed to purchase hereunder on such date, the non-defaulting Underwriters may in their discretion arrange for the purchase of such Shares by other persons satisfactory to the Company on the terms contained in this Agreement. If, within 36 hours after any such default by any Underwriter, the non-defaulting Underwriters do not arrange for the purchase of such Shares, then the Company shall be entitled to a further period of 36 hours within which to procure other persons satisfactory to the non-defaulting Underwriters to purchase such Shares on such terms. If other persons become obligated or agree to purchase the Shares of a defaulting Underwriter, either the non-defaulting Underwriters or the Company may postpone the Closing Date or the Additional Closing Date, as the case may be, for up to five full business days in order to effect any changes that in the reasonable opinion of counsel for the Company or counsel for the Underwriters may be necessary in the Registration Statement and the Prospectus or in any other document or arrangement, and the Company agrees to promptly prepare any amendment or supplement to the Registration Statement and the Prospectus that effects any such changes. As 22 used in this Agreement, the term "Underwriter" includes, for all purposes of this Agreement unless the context otherwise requires, any person not listed in Schedule 1 hereto that, pursuant to this Section 9, purchases Shares that a defaulting Underwriter agreed but failed to purchase. (b) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate number of Shares that remain unpurchased on the Closing Date or the Additional Closing Date, as the case may be, does not exceed one-tenth of the aggregate number of Shares to be purchased on such date, then the Company shall have the right to require each non-defaulting Underwriter to purchase the number of Shares that such Underwriter agreed to purchase hereunder on such date plus such Underwriter's pro rata share (based on the number of Shares that such Underwriter agreed to purchase on such date) of the Shares of such defaulting Underwriter or Underwriters for which such arrangements have not been made. (c) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate number of Shares that remain unpurchased on the Closing Date or the Additional Closing Date, as the case may be, exceeds one-tenth of the aggregate amount of Shares to be purchased on such date, or if the Company shall not exercise the right described in paragraph (b) above, then this Agreement or, with respect to any Additional Closing Date, the obligation of the Underwriters to purchase Shares on the Additional Closing Date, as the case may be, shall terminate without liability on the part of the non-defaulting Underwriters. Any termination of this Agreement pursuant to this Section 9 shall be without liability on the part of the Company, except that the Company will continue to be liable for the payment of expenses as set forth in Section 10 hereof and except that the provisions of Section 6 hereof shall not terminate and shall remain in effect. (d) Nothing contained herein shall relieve a defaulting Underwriter of any liability it may have to the Company or any non-defaulting Underwriter for damages caused by its default. 10. PAYMENT OF EXPENSES. (a) Whether or not the transactions contemplated by this Agreement are consummated or this Agreement is terminated, the Company will pay or cause to be paid all reasonable costs and expenses incident to the performance of its obligations hereunder, including without limitation, (i) the costs incident to the authorization, issuance, sale, preparation and delivery of the Shares; (ii) the costs incident to the preparation, printing and filing under the Securities Act of the Registration Statement, the Preliminary Prospectus and the Prospectus (including all exhibits, amendments and supplements thereto) and the distribution thereof; (iii) the fees and expenses of the Company's counsel and independent accountants; (iv) the fees and expenses incurred in connection with the registration or qualification and determination of eligibility for investment of the Shares under the laws of such jurisdictions as the Representatives may reasonably designate and the preparation, printing and distribution of a Blue Sky Memorandum (including the related reasonable fees and expenses of counsel for the Underwriters not to exceed $10,000, subject however, to the limitations set forth in this Section 10); (v) the cost of preparing stock certificates; (vi) the costs and charges of any transfer agent and any registrar; (vii) all costs and expenses related to the transfer and delivery of the Shares to the Underwriters, including any transfer or other taxes payable thereon; (viii) all expenses and 23 application fees incurred in connection with any filing with, and clearance of the offering by, the NASD (whether incurred by the Underwriters or not); (ix) the costs and expenses incurred by the Company relating to investor presentations on any "road show" undertaken in connection with the marketing of the offering of the Shares, including, without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations, travel and lodging expenses of the representatives and officers of the Company and any such consultants, and the cost of any aircraft chartered in connection with the road show, with the prior approval of the Company; and (x) all expenses and application fees related to the listing of the Shares on the Nasdaq National Market. Notwithstanding the foregoing provisions of this Section 10(a), the Company shall not be responsible for the payment of any fees and expenses of counsel for the Underwriters in the event that (i) the transactions contemplated by this Agreement were not consummated because the condition in Section 5(c) was not satisfied or (ii) this Agreement is terminated pursuant to Section 9(c) of this Agreement. (b) If (i) this Agreement is terminated pursuant to Section 8, (ii) the Company for any reason fails to tender the Shares for delivery to the Underwriters or (iii) the Underwriters decline to purchase the Shares for any reason permitted under this Agreement, the Company agrees to reimburse the Underwriters for all out-of-pocket costs and expenses (including the fees and expenses of their counsel) reasonably incurred by the Underwriters in connection with this Agreement and the offering contemplated hereby. Notwithstanding anything expressed or implied in the foregoing provisions of this Section 10(b), this Section 10(b) shall not apply in the event that this Agreement is terminated pursuant to Section 9(c) or in the event that the Underwriters are in material breach of their obligations under this Agreement. 11. PERSONS ENTITLED TO BENEFIT OF AGREEMENT. This Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective successors and the officers and directors and any controlling persons referred to in Section 6 hereof. Nothing in this Agreement is intended or shall be construed to give any other person any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein. No purchaser of Shares from any Underwriter shall be deemed to be a successor merely by reason of such purchase. 12. SURVIVAL. The respective indemnities, rights of contribution, representations, warranties and agreements of the Company and its subsidiaries and the Underwriters contained in this Agreement or made by or on behalf of the Company or the Underwriters pursuant to this Agreement or any certificate delivered pursuant hereto shall survive the delivery of and payment for the Shares and shall remain in full force and effect, regardless of any termination of this Agreement or any investigation made by or on behalf of the Company or the Underwriters. 13. CERTAIN DEFINED TERMS. For purposes of this Agreement, (a) except where otherwise expressly provided, the term "affiliate" has the meaning set forth in Rule 405 under the Securities Act; (b) the term "business day" means any day other than a day on which banks are permitted or required to be closed in New York City; and (c) the term "subsidiary" has the meaning set forth in Rule 405 under the Securities Act. 24 14. MISCELLANEOUS. (a) AUTHORITY OF THE REPRESENTATIVES. Any action by the Underwriters hereunder may be taken by the Representatives on behalf of the Underwriters, and any such action taken by the Representatives shall be binding upon the Underwriters. (b) NOTICES. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted and confirmed by any standard form of telecommunication. Notices to the Underwriters shall be given to the Representatives c/o [J.P. Morgan Securities Inc., 277 Park Avenue, New York, New York 10172 (fax: (212) 622-8358)]; Attention: Henry K. Wilson. Notices to the Company shall be given to it at TolerRx, Inc., 300 Technology Square, Cambridge, Massachusetts 02139 (fax: ______); Attention: __________. (c) GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the laws of the State of New York. (d) COUNTERPARTS. This Agreement may be signed in counterparts (which may include counterparts delivered by any standard form of telecommunication), each of which shall be an original and all of which together shall constitute one and the same instrument. (e) AMENDMENTS OR WAIVERS. No amendment or waiver of any provision of this Agreement, nor any consent or approval to any departure therefrom, shall in any event be effective unless the same shall be in writing and signed by the parties hereto. (f) HEADINGS. The headings herein are included for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement. (g) 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. (h) CONSENT TO JURISDICTION. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby ("RELATED PROCEEDINGS") may be instituted in the federal courts of the United States of America located in the City and County of New York or the courts of the State of New York, in each case located in the City and County of New York (collectively, the "SPECIFIED COURTS"), and each party irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any such court (a "RELATED JUDGMENT"), as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party's address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum. 25 If the foregoing is in accordance with your understanding, please indicate your acceptance of this Agreement by signing in the space provided below. Very truly yours, TOLERRX, INC. By ----------------------------- Name: Title: Accepted: __________, 2003 J.P. MORGAN SECURITIES INC. For itself and on behalf of the several Underwriters listed in Schedule 1 hereto. By ------------------------------------------ Authorized Signatory SG COWEN SECURITIES CORPORATION For itself and on behalf of the several Underwriters listed in Schedule 1 hereto. By ------------------------------------------ Authorized Signatory LEERINK, SWANN & COMPANY, INC. For itself and on behalf of the several Underwriters listed in Schedule 1 hereto. By ------------------------------------------ Authorized Signatory 26 Schedule 1 UNDERWRITER NUMBER OF SHARES - ----------- ---------------- J.P. Morgan Securities Inc.................................... SG Cowen Securities Corporation............................... Leerink Swann & Company, Inc.................................. [Other underwriters] ---------------- Total Exhibit A FORM OF LOCK-UP AGREEMENT __________, 2003 J.P. MORGAN SECURITIES INC. As Representative of the several Underwriters listed in Schedule I to the Underwriting Agreement referred to below c/o J.P. Morgan Securities Inc. 277 Park Avenue New York, NY 10172 Re: TolerRx, Inc.---Public Offering Ladies and Gentlemen: The undersigned understands that you, as Representative of the several Underwriters, propose to enter into an Underwriting Agreement (the "UNDERWRITING AGREEMENT") with TolerRx, Inc., a Delaware corporation (the "COMPANY"), providing for the public offering (the "PUBLIC OFFERING") by the several Underwriters named in Schedule I to the Underwriting Agreement (the "UNDERWRITERS"), of shares (the "SECURITIES") of common stock, par value $0.001 per share (the "COMMON STOCK"), of the Company. Capitalized terms used herein and not otherwise defined shall have the meanings set forth in the Underwriting Agreement. In consideration of the Underwriters' agreement to purchase and make the Public Offering of the Securities, and for other good and valuable consideration receipt of which is hereby acknowledged, the undersigned hereby agrees that, without the prior written consent of J.P. Morgan Securities Inc. on behalf of the Underwriters, the undersigned will not, during the period ending 180 days after the date of the prospectus relating to the Public Offering (the "PROSPECTUS"), (1) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for 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 of the Securities and Exchange Commission) EXCEPT, for securities which may be issued upon exercise of a stock option or warrant, and EXCEPT for the participation by employees of the Company in the Company's 2003 Employee Stock Purchase Plan (provided in each case that the holder of such equity of the Company has entered into an agreement on substantially the terms set forth herein), or (2) enter into any swap or other agreement that transfers, in whole or in part, any of the A-1 economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. In addition, the undersigned agrees that, without the prior written consent of J.P. Morgan Securities Inc. on behalf of the Underwriters, it will not, during the period ending 180 days after the date of the Prospectus, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. The foregoing paragraph shall not apply to transactions relating to shares of Common Stock or other securities acquired in open market transactions after completion of the Public Offering. Notwithstanding the foregoing, if the undersigned is an individual, he or she may transfer any shares of Common Stock or securities convertible into or exchangeable or exercisable for the Company's Common Stock either during his or her lifetime or on death by will or intestacy to his or her family member, to a trust the beneficiaries of which are exclusively the undersigned and/or his or her family members, to any partnership substantially all of the partners of which are the undersigned and/or his or her family members, or for other estate planning purposes; provided, however, that prior to any such transfer each transferee shall execute an agreement, satisfactory to J.P. Morgan Securities Inc. on behalf of the Underwriters, pursuant to which each transferee shall agree to receive and hold such shares of Common Stock, or securities convertible into or exchangeable or exercisable for the Common Stock, subject to the provisions hereof, and there shall be no further transfer except in accordance with the provisions hereof. For the purposes of this paragraph, "family member" shall mean spouse or equivalent domestic partner, lineal descendant, spouses of such descendants, father, mother, brother or sister of the transferor. The undersigned hereby waives any rights of the undersigned to sell shares of Common Stock or any other security issued by the Company pursuant to the Prospectus, and acknowledges and agrees that during the period ending 180 days after the date of the Prospectus the undersigned has no right to require the Company to register under the Securities Act of 1933, as amended, such Common Stock or other securities issued by the Company and beneficially owned by the undersigned. In furtherance of the foregoing, the Company, and any duly appointed transfer agent for the registration or transfer of the securities described herein, are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this Letter Agreement. The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Letter Agreement. All authority herein conferred or agreed to be conferred and any obligations of the undersigned shall be binding upon the successors, assigns, heirs or personal representatives of the undersigned. The undersigned understands that, 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 thereunder, the undersigned shall be released from all obligations under this Letter Agreement. The undersigned understands that the Underwriters are entering into the Underwriting Agreement and proceeding with the Public Offering in reliance upon this Letter Agreement. A-2 This lock-up agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to the conflict of laws principles thereof. Very truly yours, Name of Stockholder: -------------------------------- Signature of Stockholder: -------------------------------- A-3