REGISTRATION RIGHTS AGREEMENT

ABGENIX, INC.



REGISTRATION RIGHTS AGREEMENT



This Agreement is made as of November 18, 1998 by and between Abgenix, Inc., a Delaware corporation (the "Company"), and the persons and entities listed on the Schedule of Holders attached hereto as Schedule 1 (the "Holders").



WHEREAS, pursuant to a Stock Purchase Agreement (the "CG Agreement") of even date herewith between Cell Genesys, Inc., a Delaware corporation ("CG"), and the Holders, CG is selling 1,146,300 shares of the Company's Common Stock (the "Shares") to the Holders for the purchase price of $9,499,961.25; and



WHEREAS, to induce the Holders to enter into the CG Agreement, the Company has agreed to provide the Holders with certain registration rights with respect to the Shares pursuant to the terms and conditions of this Agreement;



NOW, THEREFORE, in consideration of the mutual promises, covenants and conditions set forth in this Agreement, the Company and the Holders agree as follows:



1. Certain Definitions. As used in this Agreement, the following terms shall have the following respective meanings:



Business Day. Each Monday, Tuesday, Wednesday, Thursday and Friday that is not a day on which banking institutions in New York are authorized or obligated by law or executive order to close.



Effectiveness Period. See Section 2(a) hereof.



Exchange Act. The Securities Exchange Act of 1934, as amended, or any similar federal statute and the rules and regulations of the SEC promulgated thereunder.



Initial Shelf Registration. See Section 2(a) hereof.



Losses. See Section 5(a) hereof.



Prospectus. The prospectus included in any Registration Statement (including, without limitation, a prospectus that discloses information previously omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430A promulgated under the Securities Act), as amended or supplemented by any prospectus supplement, including, without limitation, with respect to the terms of the offering of any portion of the Registrable Securities covered by such Registration Statement and all other amendments and supplements to the Prospectus, including post-effective amendments, and all material incorporated by reference or deemed to be incorporated by reference in such Prospectus. Such Prospectus and any amendments or supplements shall comply with the Securities Act.







Register. The terms "register," "registered" and "registration" refer to a registration effected by preparing and filing a registration statement in compliance with the Securities Act, and the declaration or ordering of the effectiveness of such registration statement by the SEC.



Registrable Securities. The Shares or other securities issued or issuable with respect to the Shares as a result of any stock split, stock dividend, recapitalization, exchange, combination, merger, consolidation, distribution or similar event.



Registration Expenses. See Section 4 hereof.



Registration Statement. Any registration statement of the Company which covers any of the Registrable Securities pursuant to the provisions of this Agreement, including the Prospectus, amendments and supplements to such registration statement, including post-effective amendments, all exhibits, and all material incorporated by reference or deemed to be incorporated by reference in such registration statement. Such Registration Statement and any amendments or supplements thereto shall comply with the Securities Act.



Replacement Shelf Registration. See Section 2(b) hereof.



Rule 144. Rule 144 under the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the SEC.



SEC. The Securities and Exchange Commission.



Securities Act. The Securities Act of 1933, as amended, and the rules and regulations promulgated by the SEC thereunder.



Shelf Registration. See Section 2 hereof.



Special Counsel. Proskauer Rose LLP, or such other successor counsel as shall be specified by the Zesiger Capital Group LLC ("ZCG") on behalf of the Holders as special counsel to the Holders, the fees and expenses of which will be paid by the Company pursuant to Section 4 hereof.



Subsequent Shelf Registration. See Section 2(c) hereof.



2. Shelf Registration.



(a) The Company shall prepare and file with the SEC, not later than January 15, 1999, a Registration Statement for an offering to be made on a continuous basis pursuant to Rule 415 of the Securities Act (a "Shelf Registration") covering all of the Registrable Securities (the "Initial Shelf Registration"). The Initial Shelf Registration shall be on Form S-1. The Company shall use its reasonable efforts to cause the Initial Shelf Registration to be declared effective under the Securities Act by the SEC as soon as practicable (but in no event on or prior to January 28, 1999) and to keep the Initial Shelf Registration continuously effective under the Securities Act until November 18, 2000 (the "Effectiveness Period"), or such shorter period ending when (i) all Registrable Securities covered by the Initial Shelf Registration have been sold or shall have ceased to be Registrable Securities, (ii) the







Replacement Shelf Registration, as defined below, covering all of the Registrable Securities has been declared effective under the Securities Act or (iii) a Subsequent Shelf Registration, as defined below, covering all of the Registrable Securities has been declared effective under the Securities Act.



(b) As soon as the Company is eligible to use Form S-3 permitting registration of the Company's securities for resale by the Holders, the Company shall prepare and file with the SEC a Registration Statement for a Shelf Registration covering all of the Registrable Securities (the "Replacement Shelf Registration"). The Replacement Shelf Registration shall be on Form S-3 or another appropriate form permitting registration of such Registrable Securities for resale by the Holders. On the date that the Replacement Shelf Registration is declared effective under the Securities Act by the SEC, the Company shall withdraw the Initial Shelf Registration and no further sales of Registrable Securities shall be made pursuant to the Initial Shelf Registration as of such date; provided, however, that in no event shall the Initial Shelf Registration be withdrawn until such time as the Replacement Shelf Registration has been declared effective under the Securities Act by the SEC. After the Replacement Shelf Registration has been declared effective by the SEC, the Company shall use reasonable efforts to keep the Replacement Shelf Registration continuously effective under the Securities Act until the end of the Effectiveness Period or such shorter period ending when (i) all Registrable Securities covered by the Replacement Shelf Registration have been sold or shall have ceased to be Registrable Securities, or (ii) a Subsequent Shelf Registration, as defined below, covering all of the Registrable Securities has been declared effective under the Securities Act.



(c) If the Initial Shelf Registration, Replacement Shelf Registration or any Subsequent Shelf Registration, as defined below, ceases to be effective for any reason at any time during the Effectiveness Period (other than because all Registerable Securities registered thereunder shall have been sold or shall have ceased to be Registerable Securities), the Company shall use its best efforts to obtain the prompt withdrawal of any order suspending the effectiveness thereof, and in any event shall within 45 days of such cessation of effectiveness amend the Shelf Registration in a manner reasonably expected to obtain the withdrawal of the order suspending the effectiveness thereof, or file an additional "shelf" Registration Statement pursuant to Rule 415 of the Securities Act covering all of the Registrable Securities (a "Subsequent Shelf Registration"). If a Subsequent Shelf Registration is filed, the Company shall use its best efforts to cause the Subsequent Shelf Registration to be declared effective under the Securities Act by the SEC as soon as practicable after such filing and shall use reasonable efforts to keep such Registration Statement continuously effective until the end of the Effectiveness Period.



(d) The Company shall supplement and amend the Shelf Registration if required by the rules, regulations or instructions applicable to the registration form used by the Company for such Shelf Registration, if required by the Securities Act, or if reasonably requested by any Holder or by any underwriter of the Registrable Securities.



3. Registration Procedures. In connection with the Company's registration obligations under Section 2 hereof, the Company shall effect such registrations to permit the sale of the Registrable Securities in accordance with the intended method or methods of disposition thereof and pursuant thereto the Company shall as expeditiously as possible:



(a) Prepare and file with the SEC a Registration Statement or Registration Statements on any appropriate form under the Securities Act available for the sale of the Registrable Securities by







the Holders in accordance with the intended method or methods of distribution thereof, and cause each such Registration Statement to become effective and remain effective as provided herein; provided, that before filing any such Registration Statement or Prospectus or any amendments or supplements thereto (other than documents that would be incorporated or deemed to be incorporated therein by reference and that the Company is required by applicable securities laws or stock exchange requirements to file) the Company shall furnish to the Special Counsel and the managing underwriters of such offering, if any, copies of all such documents proposed to be filed, which documents will be subject to the review of the Special Counsel and such underwriters.



(b) Prepare and file with the SEC such amendments and post-effective amendments to each Registration Statement as may be necessary to keep such Registration Statement continuously effective for the applicable period specified in Section 2; cause the related Prospectus to be timely supplemented by any required Prospectus supplement, and as so supplemented to be filed pursuant to Rule 424 (or any similar provisions then in force) under the Securities Act; and comply with the provisions of the Securities Act with respect to the disposition of all securities covered by such Registration Statement during the applicable period in accordance with the intended methods of disposition by the Holders set forth in such Registration Statement as so amended or such Prospectus as so supplemented.



(c) Notify the Holders, the Special Counsel and the managing underwriters, if any, promptly, and (if requested by any such person) confirm such notice in writing, (i) when a Prospectus or any Prospectus supplement or post-effective amendment has been filed, and, with respect to a Registration Statement or any post-effective amendment, when the same has become effective, (ii) of any request by the SEC or any other federal or state governmental authority during the period of effectiveness of the Registration Statement for amendments or supplements to a Registration Statement or related Prospectus or for additional information, (iii) of the issuance by the SEC or any other federal or state governmental authority of any stop order suspending the effectiveness of a Registration Statement or the initiation of any proceedings for that purpose, (iv) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from qualification of any of the Registrable Securities for sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose, (v) of the happening of any event which makes any statement made in such Registration Statement or related Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue in any material respect or which requires the making of any changes in the Registration Statement or Prospectus so that, in the case of the Registration Statement, it will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and that in the case of the Prospectus, it will not contain any untrue statement of a material fact or omit to state any material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, and (vi) of the Company's reasonable determination that a post-effective amendment to a Registration Statement would be appropriate.



(d) Use every reasonable effort to obtain the withdrawal of any order suspending the effectiveness of a Registration Statement, or the lifting of any suspension of the qualification (or exemption from qualification) of any of the Registrable Securities for sale in any jurisdiction, at the earliest possible moment.







(e) Subject to the last paragraph of this Section 3, if reasonably requested by the managing underwriters, if any, or the Holders (i) promptly incorporate in a Prospectus supplement or post-effective amendment such information as the managing underwriters, if any, or the Holders agrees should be included therein as required by applicable law, (ii) make all required filings of such Prospectus supplement or such post-effective amendment as soon as practicable after the Company has received notification of the matters to be incorporated in such Prospectus supplement or post-effective amendment, and (iii) supplement or make amendments to any Registration Statement consistent with clause (i) or (ii) above; provided, that the Company shall not be required to take any actions under this Section 3(e) that are not, in the opinion of counsel for the Company, necessary or advisable to comply with applicable law.



(f) Furnish to the Holders, the Special Counsel and each managing underwriter, if any, without charge, at least one conformed copy of the Registration Statement or Registration Statements and any post-effective amendment thereto, including financial statements but excluding schedules, all documents incorporated or deemed to be incorporated therein by reference and all exhibits (unless requested in writing by the Holders, Special Counsel or managing underwriter, if any).



(g) Promptly deliver to the Holders, the Special Counsel and the underwriters, if any, without charge, as many copies of the Prospectus or Prospectuses relating to such Registrable Securities (including each preliminary prospectus) and any amendment or supplement thereto as such persons may reasonably request; and the Company hereby consents to the use of such Prospectus or each amendment or supplement thereto by the Holders and the underwriters, if any, in connection with the offering and sale of the Registrable Securities covered by such Prospectus or any amendment or supplement thereto.



(h) Prior to any public offering of Registrable Securities, to register or qualify or cooperate with the Holders, the underwriters, if any, and the Special Counsel in connection with the registration or qualification (or exemption from such registration or qualification) of such Registrable Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions within the United States as the Holders or underwriter, if any, reasonably requests in writing; keep each such registration or qualification (or exemption therefrom) effective during the period such Registration Statement is required to be kept effective and do any and all other acts or things necessary or advisable to enable the disposition in such jurisdictions of the Registrable Securities covered by the applicable Registration Statement; provided, that the Company will not be required to (i) qualify generally to do business in any jurisdiction where it is not then so qualified or (ii) take any action that would subject it to general service of process in suits or to taxation in any such jurisdiction where it is not then so subject.



(i) Cause the Registrable Securities covered by the applicable Registration Statement to be registered with or approved by such other governmental agencies or authorities within the United States, except as may be required solely as a consequence of the nature of a Holder in which case the Company will cooperate in all reasonable respects with the filing of such Registration Statement and the granting of such approvals, as may be necessary to enable the Holders or the underwriters, if any, to consummate the disposition of such Registrable Securities.



(j) Upon the occurrence of any event contemplated by Section 3(c)(v) or 3(c)(vi) above, prepare a supplement or post-effective amendment to each Registration Statement or a supplement to the related Prospectus or any document incorporated therein by reference or file any other







required document so that, as thereafter delivered to the purchasers of the Registrable Securities being sold thereunder, such Prospectus will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading.



(k) Enter into such agreements (including, in the event of an underwritten offering, an underwriting agreement in form, scope and substance as is customary in underwritten offerings) and take all such other actions in connection therewith (including, in the event of an underwritten offering, those reasonably requested by the managing underwriters, if any, or the Holders) in order to expedite or facilitate the disposition of such Registrable Securities and in such connection, whether or not an underwriting agreement is entered into and if the registration is an underwritten registration, (i) make such representations and warranties, subject to the Company's ability to do so, to the Holders and the underwriters, if any, with respect to the business of the Company and its subsidiaries, the Registration Statement, Prospectus and documents incorporated by reference or deemed incorporated by reference, if any, in each case, in form, substance and scope as are customarily made by issuers to underwriters in underwritten offerings and confirm the same if and when requested; (ii) use its reasonable efforts to obtain opinions of counsel to the Company and updates thereof (which counsel and opinions (in form, scope and substance) shall be reasonably satisfactory to the managing underwriters, if any, Special Counsel and the Holders) addressed to the Holders and each of the underwriters, if any, covering the matters customarily covered in opinions requested in underwritten offerings; (iii) use its reasonable efforts to obtain "cold comfort" letters and updates thereof from the independent certified public accountants of the Company (and, if necessary, any other certified public accountants of any subsidiary of the Company or any business acquired or to be acquired by the Company for which financial statements and financial data i ...