Form Of Underwriting Agreement

000,000 SHARES(1)


ABGENIX, INC.


COMMON STOCK


UNDERWRITING AGREEMENT


____ __, 1998


BANCAMERICA ROBERTSON STEPHENS LEHMAN BROTHERS INC.
As Representatives of the several Underwriters c/o BancAmerica Robertson Stephens 555 California Street Suite 2600 San Francisco, California 94104


Ladies/Gentlemen:


Abgenix, Inc., a Delaware corporation (the "Company"), addresses you as the Representatives of each of the persons, firms and corporations listed in Schedule A hereto (herein collectively called the "Underwriters") and each hereby confirms its agreement with the several Underwriters as follows:


1. Description of Shares. The Company proposes to issue and sell 3,000,000 shares of its authorized and unissued Common Stock, 0.0001 par value per share (the "Firm Shares") to the several Underwriters. The Company also proposes to grant to the Underwriters an option to purchase up to 450,000 additional shares of the Company's Common Stock, 0.0001 par value per share (the "Option Shares"), as provided in Section 7 hereof. As used in this Agreement, the term "Shares" shall include the Firm Shares and the Option Shares. All shares of Common Stock, 0.0001 par value per share, of the Company to be outstanding after giving effect to the sales contemplated hereby, including the Shares, are hereinafter referred to as "Common Stock."


2. Representations, Warranties and Agreements of the Company


I. The Company represents and warrants to and agrees with each Underwriter that:


(a) A registration statement on Form S-1 (File No. 333-49415) with respect to the Shares, including a prospectus subject to completion, has been prepared by the Company in conformity with the requirements of the Securities Act of 1933, as amended (the "Act"), and the applicable rules and regulations (the "Rules and Regulations") of the Securities and Exchange Commission (the "Commission") under the Act and has been filed with the Commission; such amendments to such registration statement, such amended prospectuses subject to completion and such abbreviated registration statements pursuant to Rule 462(b) of the Rules and Regulations as may have been required prior to the date hereof have been similarly prepared and filed with the Commission; and the Company will file such additional amendments to such registration statement, such amended prospectuses subject to completion and such abbreviated registration statements as may hereafter be required.


- -------- (1) Plus an option to purchase up to 450,000 additional shares from the
Company to cover over-allotments.


1.


2 Copies of such registration statement and amendments, of each related prospectus subject to completion (the "Preliminary Prospectuses") and of any abbreviated registration statement pursuant to Rule 462(b) of the Rules and Regulations have been delivered to you.


If the registration statement relating to the Shares has been declared effective under the Act by the Commission, the Company will prepare and promptly file with the Commission the information omitted from the registration statement pursuant to Rule 430A(a) or, if BancAmerica Robertson Stephens, on behalf of the several Underwriters, shall agree to the utilization of Rule 434 of the Rules and Regulations, the information required to be included in any term sheet filed pursuant to Rule 434(b) or (c), as applicable, of the Rules and Regulations pursuant to subparagraph (1), (4) or (7) of Rule 424(b) of the Rules and Regulations or as part of a post-effective amendment to the registration statement (including a final form of prospectus). If the registration statement relating to the Shares has not been declared effective under the Act by the Commission, the Company will prepare and promptly file an amendment to the registration statement, including a final form of prospectus, or, if BancAmerica Robertson Stephens, on behalf of the several Underwriters, shall agree to the utilization of Rule 434 of the Rules and Regulations, the information required to be included in any term sheet filed pursuant to Rule 434(b) or (c), as applicable, of the Rules and Regulations. The term "Registration Statement" as used in this Agreement shall mean such registration statement, including financial statements, schedules and exhibits, in the form in which it became or becomes, as the case may be, effective (including, if the Company omitted information from the registration statement pursuant to Rule 430A(a) or files a term sheet pursuant to Rule 434 of the Rules and Regulations, the information deemed to be a part of the registration statement at the time it became effective pursuant to Rule 430A(b) or Rule 434(d) of the Rules and Regulations) and, in the event of any amendment thereto or the filing of any abbreviated registration statement pursuant to Rule 462(b) of the Rules and Regulations relating thereto after the effective date of such registration statement, shall also mean (from and after the effectiveness of such amendment or the filing of such abbreviated registration statement) such registration statement as so amended, together with any such abbreviated registration statement. The term "Prospectus" as used in this Agreement shall mean the prospectus relating to the Shares as included in such Registration Statement at the time it becomes effective (including, if the Company omitted information from the Registration Statement pursuant to Rule 430A(a) of the Rules and Regulations, the information deemed to be a part of the Registration Statement at the time it became effective pursuant to Rule 430A(b) of the Rules and Regulations); provided, however, that if in reliance on Rule 434 of the Rules and Regulations and with the consent of BancAmerica Robertson Stephens, on behalf of the several Underwriters, the Company shall have provided to the Underwriters a term sheet pursuant to Rule 434(b) or (c), as applicable, prior to the time that a confirmation is sent or given for purposes of Section 2(10)(a) of the Act, the term "Prospectus" shall mean the "prospectus subject to completion" (as defined in Rule 434(g) of the Rules and Regulations) last provided to the Underwriters by the Company and circulated by the Underwriters to all prospective purchasers of the Shares (including the information deemed to be a part of the Registration Statement at the time it became effective pursuant to Rule 434(d) of the Rules and Regulations). Notwithstanding the foregoing, if any revised prospectus shall be provided to the Underwriters by the Company for use in connection with the offering of the Shares that differs from the prospectus referred to in the immediately preceding sentence (whether or not such revised prospectus is required to be filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations), the term "Prospectus" shall refer to such revised prospectus from and after the time it is first provided to the Underwriters for such use. If in reliance on Rule 434 of the Rules and Regulations and with the consent of BancAmerica Robertson Stephens, on behalf of the several Underwriters, the Company shall have provided to the Underwriters a term sheet pursuant to Rule 434(b) or (c), as applicable, prior to the time that a confirmation is sent or given for purposes of Section 2(10)(a) of the Act, the Prospectus and the term sheet, together, will not be materially different from the prospectus in the Registration Statement.


(b) The Commission has not issued any order preventing or suspending the use of any Preliminary Prospectus or instituted proceedings for that purpose, and each such Preliminary Prospectus has conformed in all material respects to the requirements of the Act and the Rules and Regulations and, as of its date, has not included any untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and at the time the Registration Statement became or becomes, as the case may be, effective and at all times subsequent thereto up to and on the Closing Date (hereinafter defined) and on any later date on which Option Shares are to be purchased, (i) the Registration Statement and the Prospectus, and any amendments or supplements thereto, contained and will contain all material information required to be included therein by the Act and the Rules and Regulations and will in all material respects conform to the requirements of the Act and the Rules and Regulations, (ii) the Registration


2. 3 Statement, and any amendments or supplements thereto, did not and will not include any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, and (iii) the Prospectus, and any amendments or supplements thereto, did not and will not include any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that none of the representations and warranties contained in this subparagraph (b) shall apply to information contained in or omitted from the Registration Statement or Prospectus, or any amendment or supplement thereto, in reliance upon, and in conformity with, written information relating to any Underwriter furnished to the Company by such Underwriter specifically for use in the preparation thereof.


(c) The Company does not own or control, directly or indirectly, any corporation, association or other entity other than Xenotech, Inc., a Delaware corporation ("Xenotech, Inc.") and Xenotech, L.P. a California limited partnership (Xenotech, L.P.") (collectively, the "subsidiaries"). Each of the Company and its subsidiaries has been duly organized and is validly existing and in good standing under the laws of the jurisdiction of its organization with full power and authority to own, lease and operate its properties and conduct its business as described in the Prospectus; the Company owns all of the outstanding capital stock or other equity interests of its subsidiaries free and clear of any pledge, lien, security interest, encumbrance, claim or equitable interest; each of the Company and its subsidiaries is duly qualified to do business and is in good standing in each jurisdiction in which the ownership or leasing of its properties or the conduct of its business requires such qualification, except where the failure to be so qualified or be in good standing would not have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise; no proceeding has been instituted in any such jurisdiction, revoking, limiting or curtailing, or seeking to revoke, limit or curtail, such power and authority or qualification; each of the Company and its subsidiaries is in possession of and operating in compliance with all authorizations, licenses, certificates, consents, orders and permits from state, federal and other regulatory authorities which are material to the conduct of its business, all of which are valid and in full force and effect; neither the Company nor any of its subsidiaries is in violation of its respective charter or bylaws or in default in the performance or observance of any material obligation, agreement, covenant or condition contained in any material bond, debenture, note or other evidence of indebtedness, or in any material lease, contract, indenture, mortgage, deed of trust, loan agreement, joint venture or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which it or any of its subsidiaries or their respective properties may be bound; and neither the Company nor any of its subsidiaries is in material violation of any law, order, rule, regulation, writ, injunction, judgment or decree of any court, government or governmental agency or body, domestic or foreign, having jurisdiction over the Company or any of its subsidiaries or over their respective properties of which it has knowledge.


(d) The Company has full legal right, power and authority to enter into this Agreement and perform the transactions contemplated hereby. This Agreement has been duly authorized, executed and delivered by the Company and is a valid and binding agreement on the part 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 applicable bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting creditors' rights generally or by general equitable principles; the performance of this Agreement and the consummation of the transactions herein contemplated will not result in a material breach or violation of any of the terms and provisions of, or constitute a default under, (i) any bond, debenture, note or other evidence of indebtedness, or under any lease, contract, indenture, mortgage, deed of trust, loan agreement, joint venture or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which it or any of its subsidiaries or their respective properties may be bound, (ii) the charter or bylaws of the Company or any of its subsidiaries, or (iii) any law, order, rule, regulation, writ, injunction, judgment or decree of any court, government or governmental agency or body, domestic or foreign, having jurisdiction over the Company or any of its subsidiaries or over their respective properties. No consent, approval, authorization or order of or qualification with any court, government or governmental agency or body, domestic or foreign, having jurisdiction over the Company or any of its subsidiaries or over their respective properties is required for the execution and delivery of this Agreement and the consummation by the Company or any of its subsidiaries of the transactions herein contemplated, except such as may be required under the Act or under state or other securities or Blue Sky laws, all of which requirements have been satisfied in all material respects.


3. 4
(e) There is not any pending or, to the best of the Company's knowledge, threatened action, suit, claim or proceeding against the Company, any of its subsidiaries or any of their respective officers or any of their respective properties, assets or rights before any court, government or governmental agency or body, domestic or foreign, having jurisdiction over the Company or any of its subsidiaries or over their respective officers or properties or otherwise which (i) might result in any material adverse change in the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise or might materially and adversely affect their properties, assets or rights, (ii) might prevent consummation of the transactions contemplated hereby or (iii) is required to be disclosed in the Registration Statement or Prospectus and is not so disclosed; and there are no agreements, understandings, arrangements, contracts, leases or documents of the Company or any of its subsidiaries of a character required to be described or referred to in the Registration Statement or Prospectus or to be filed as an exhibit to the Registration Statement by the Act or the Rules and Regulations which have not been accurately described in all material respects in the Registration Statement or Prospectus and filed as exhibits to the Registration Statement.


(f) All outstanding shares of capital stock of the Company have been duly authorized, validly issued and are fully paid and nonassessable, have been issued in compliance with all federal and state securities laws, were not issued in violation of or subject to any preemptive rights or other rights to subscribe for or purchase securities, and the authorized and outstanding capital stock of the Company is as set forth in the Prospectus under the caption "Capitalization" as of the date stated therein and conforms in all material respects to the statements relating thereto contained in the Registration Statement and the Prospectus (and such statements correctly state the substance of the instruments defining the capitalization of the Company); the Firm Shares and the Option Shares have been duly authorized for issuance and sale to the Underwriters and, when issued and delivered by the Company against payment therefor in accordance with the terms of this Agreement, will be duly and validly issued, fully paid and nonassessable, and will be issued, sold and transferred to the Underwriters free and clear of any pledge, lien, security interest, encumbrance, claim or equitable interest; and no preemptive right, co-sale right, registration right, right of first refusal or other similar right of stockholders exists with respect to any of the Firm Shares or Option Shares or the issuance and sale thereof other than those that have been expressly waived prior to the date hereof and those that will automatically expire upon and will not apply to the consummation of the transactions contemplated by this Agreement. No further approval or authorization of any stockholder, the Board of Directors of the Company or others is required for the issuance, sale or transfer of the Shares except as may be required under the Act or under state or other securities or Blue Sky laws. All issued and outstanding shares of capital stock of Xenotech, Inc. have been duly authorized and validly issued and are fully paid and nonassessable, and were not issued in violation of or subject to any preemptive right, or other rights to subscribe for or purchase shares and are owned by the Company free and clear of any pledge, lien, security interest, encumbrance, claim or equitable interest. All issued and outstanding limited partnership interests of Xenotech, L.P. have been duly authorized and validly issued and are fully paid and nonassessable, and were not issued in violation of or subject to any preemptive right, or other similar right, and the limited partnership interests owned by the Company are free and clear of any pledge, lien, security interest, encumbrance, claim or equitable interest. Except as disclosed in the Prospectus and the financial statements of the Company, and the related notes thereto, included in the Prospectus, neither the Company nor its subsidiaries has outstanding any options to purchase, or any preemptive rights or other rights to subscribe for or to purchase, any securities, interests or obligations convertible into, or any contracts or commitments to issue or sell, shares of its capital stock or any such options, rights, convertible securities or obligations. The description of the Company's each of the stock option, stock bonus and other equity incentive plans or arrangements, and the options or other rights granted, exercised or exercisable thereunder, set forth in the Prospectus accurately and fairly presents the information required to be shown with respect to such plans, arrangements, options and rights.


(g) Ernst & Young LLP, which has examined the consolidated financial statements of the Company and Xenotech, L.P., together with the related schedules and notes, as of December 31, 1996 and 1997 and for each of the years in the three (3) years ended December 31, 1997 filed with the Commission as a part of the Registration Statement, which are included in the Prospectus, are independent accountants within the meaning of the Act and the Rules and Regulations; the audited consolidated financial statements of the Company and Xenotech, L.P., together with the related schedules and notes, and the unaudited consolidated financial information, forming part of the Registration Statement and Prospectus, fairly present the financial position and the results of operations of the Company and its subsidiaries and Xenotech, L.P., at the respective dates and for the respective periods to which they apply; and all audited consolidated financial statements of the Company and Xenotech, L.P., together


4. 5 with the related schedules and notes, and the unaudited consolidated financial information, filed with the Commission as part of the Registration Statement, have been prepared in accordance with generally accepted accounting principles consistently applied throughout the periods involved except as may be otherwise stated therein. The selected and summary financial and statistical data included in the Registration Statement present fairly the information shown therein and have been compiled on a basis consistent with the audited financial statements presented therein. No other financial statements or schedules are required to be included in the Registration Statement.


(h) Subsequent to the respective dates as of which information is given in the Registration Statement and Prospectus, there has not been (i) any material adverse change in the condition (financial or otherwise), earnings, operations, rights, business or business prospects of the Company and its subsidiaries considered as one enterprise, (ii) any transaction that is material to the Company and its subsidiaries considered as one enterprise, except transactions entered into in the ordinary course of business, (iii) any obligation, direct or contingent, that is material to the Company and its subsidiaries considered as one enterprise, incurred by the Company or its subsidiaries, except obligations incurred in the ordinary course of business, (iv) any change in the capital stock or outstanding indebtedness of the Company or any of its subsidiaries that is material to the Company and its subsidiaries considered as one enterprise, (v) any dividend or distribution of any kind declared, paid or made on the capital stock of the Company or any of its subsidiaries, or (vi) any loss or damage (whether or not insured) to the property of the Company or any of its subsidiaries which has been sustained or will have been sustained which has a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise.


(i) Except as set forth in the Registration Statement and Prospectus, (i) each of the Company and its subsidiaries has good and marketable title to all properties and assets described in the Registration Statement and Prospectus as owned by it, free and clear of any pledge, lien, security interest, encumbrance, claim or equitable interest, other than such as would not have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise, (ii) the agreements to which the Company or any of its subsidiaries is a party described in the Registration Statement and Prospectus are valid agreements, enforceable by the Company and its subsidiaries (as applicable), except as the enforcement thereof may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting creditors' rights generally or by general equitable principles and, to the best of the Company's knowledge, the other contracting party or parties thereto are not in material breach or material default under any of such agreements, and (iii) each of the Company and its subsidiaries has valid and enforceable leases for all properties described in the Registration Statement and Prospectus as leased by it, except as the enforcement thereof may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting creditors' rights generally or by general equitable principles. Except as set forth in the Registration Statement and Prospectus, the Company owns or leases all such properties as are necessary to its operations as now conducted or as proposed to be conducted.


(j) The Company and its subsidiaries have timely filed all necessary federal, state and foreign income and franchise tax returns and have paid all taxes shown thereon as due, and there is no tax deficiency that has been or, to the best of the Company's knowledge, might be asserted against the Company or any of its subsidiaries that might have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise; and all tax liabilities are adequately provided for on the books of the Company and its subsidiaries.


(k) The Company and its subsidiaries maintain insurance with insurers of recognized financial responsibility of the types and in the amounts generally deemed adequate for their respective businesses and consistent with insurance coverage maintained by similar companies in similar businesses, including, but not limited to, insurance covering real and personal property owned or leased by the Company or its subsidiaries against theft, damage, destruction, acts of vandalism and all other risks customarily insured against, all of which insurance is in full force and effect; neither the Company nor any such subsidiary has been refused any insurance coverage sought or applied for; and neither the Company nor any such subsidiary has 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 from similar insurers as may be necessary to continue its business at a cost that would not materially and adversely affect


5. 6 the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise.


(l) No labor disturbance by the employees of the Company or any of its subsidiaries exists or is imminent; and the Company is not aware of any existing or imminent labor disturbance by the employees of any of its principal suppliers that might be expected to result in a material adverse change in the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise. No collective bargaining agreement exists with any of the Company's employees and, to the best of the Company's knowledge, no such agreement is imminent.


(m) Each of the Company and its subsidiaries owns or possesses adequate rights to use all patents, patent rights, inventions, trade secrets, know-how, trademarks, service marks, trade names and copyrights which are necessary to conduct its businesses as described in the Registration Statement and Prospectus; no patents, patent rights, trade secrets, trademarks, service marks, trade names or copyrights that would have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise have expired or terminated, and no patents, patent rights, trade secrets, trademarks, service marks, trade names or copyrights that would have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise will expire or terminate prior to five (5) years from the Closing Date (as hereinafter defined); the Company has not received any notice of, and has no knowledge of facts which could form the basis of a claim of, any infringement of or conflict with asserted rights of the Company by others with respect to any patent, patent rights, inventions, trade secrets, know-how, trademarks, service marks, trade names or copyrights; and the Company has not received any notice of, and has no knowledge of, any infringement of or conflict with asserted rights of others with respect to any patent, patent rights, inventions, trade secrets, know-how, trademarks, service marks, trade names or copyrights which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, might have a material adverse effect on the condition (financial or otherwise), earnings, operations, business or business prospects of the Company and its subsidiaries considered as one enterprise.


(n) The Common Stock has been approved for quotation on The Nasdaq National Market, subject to official notice of issuance.


(o) The Company has been advised concerning the Investment ...