<PAGE>
                            STOCK PURCHASE AGREEMENT

Abgenix, Inc.
7601 Dumbarton Circle
Fremont, CA 94555

Cell Genesys, Inc.
342 Lakeside Drive
Foster City, CA 94404

Ladies & Gentlemen:

      The undersigned, _________________________________(the "Investor"), hereby
confirms its agreement with you as follows:

1. This Stock Purchase Agreement (the "Agreement") is made as of October ___,
2000 between Abgenix, Inc., a Delaware corporation (the "Company"), Cell
Genesys, Inc., a Delaware corporation ("Current Stockholder") and the Investor.

2. The Company has authorized the sale and issuance of up to _____________
shares (the "Company Shares") of common stock of the Company, $0.0001 par value
per share (the "Common Stock") and the Current Stockholder has authorized the
sale of up to ____________ shares of Common Stock (the "Current Stockholder
Shares"; and together with the Company Shares, the "Shares"), subject to
adjustment by the Company's Board of Directors, to certain investors in a
private placement (the "Offering"). 82 percent of the Shares to be sold in the
Offering will be offered, issued and sold by the Company and 18 percent of the
Shares to be sold in the Offering will be offered and sold by the Current
Stockholder.

3. The Company, the Current Stockholder and the Investor agree that the Investor
will purchase from the Company and the Current Stockholder, and the Company will
issue and sell and the Current Stockholder will sell to the Investor,
___________ and ______________ Shares, respectively, for a purchase price of
$_______ per share, or an aggregate purchase price of $_______________, pursuant
to the Terms and Conditions for Purchase of Shares attached hereto as Annex I
and incorporated herein by reference as if fully set forth herein. Unless
otherwise requested by the Investor, certificates representing the Shares
purchased by the Investor will be registered in the Investor's name and address
as set forth below.

4. The Investor represents that, except as set forth below, (a) it has had no
position, office or other material relationship within the past three years with
the Company, the Current Stockholder or persons known to it to be affiliates of
the Company or the Current Stockholder, (b) neither it, nor any group of which
it is a member or to which it is related, beneficially owns (including the right
to acquire or vote) any securities of the Company and (c) it has no direct or
indirect affiliation or association with any NASD member as of the date hereof.
Exceptions:

________________________________________________________________________________
________________________________________________________________________________
                 (If no exceptions, write "none." If left blank,
                     response will be deemed to be "none.")

      Please confirm that the foregoing correctly sets forth the agreement
between us by signing in the space provided below for that purpose. By executing
this Agreement, you acknowledge that the Company may use the information in
paragraph 4 above and the name and address information below in preparation of
the Registration Statement (as defined in Annex 1).

                  [Remainder of Page Intentionally Left Blank]


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<PAGE>

                  [SIGNATURE PAGE TO STOCK PURCHASE AGREEMENT]

                          By:
                               ----------------------------------

                          Print Name:
                                      ---------------------------

                          Title:
                                 --------------------------------

                          Address:
                                   ------------------------------


                          Tax ID No.:
                                      ---------------------------

                          Contact name:
                                        -------------------------

                          Telephone:

                          Name in which shares should registered (if different):

                          ------------------------------------------------------


AGREED AND ACCEPTED:
-------------------

ABGENIX, INC.

------------------------------
By:
Title:


CELL GENESYS, INC.

------------------------------
By:
Title:


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                                     ANNEX I

                   TERMS AND CONDITIONS FOR PURCHASE OF SHARES

      1. Authorization and Sale of the Shares. Subject to these Terms and
Conditions for Purchase of Shares (these "Terms and Conditions") the Company has
authorized the sale of up to __________ Company Shares, and the Current
Stockholder has committed to sell up to _________ Current Stockholder Shares.
The Company reserves the right to proportionally increase or decrease these
numbers.

      2. Agreement to Sell and Purchase the Shares; Subscription Date.

            2.1 At the Closing (as defined in Section 3), the Company and the
Current Stockholder will sell to the Investor, and the Investor will purchase
from the Company and the Current Stockholder, upon the terms and conditions
hereinafter set forth, the number of Shares set forth in the Stock Purchase
Agreement to which these Terms and Conditions are annexed at the purchase price
set forth therein.

            2.2 The Company and the Current Stockholder may enter into this same
form of Stock Purchase Agreement with certain other investors (the "Other
Investors") and expects to complete sales of Shares to them. (The Investor and
the Other Investors are hereinafter sometimes collectively referred to as the
"Investors," and this Agreement and the Stock Purchase Agreements executed by
the Other Investors are hereinafter sometimes collectively referred to as the
"Agreements.") The Company, on behalf of itself and the Current Stockholder, may
accept executed Agreements from Investors for the purchase of Shares commencing
upon the date on which the Company provides the Investors with the proposed
purchase price per Share and concluding upon the date (the "Subscription Date")
on which (i) the Company and the Current Stockholder have executed Agreements
with Investors for the purchase of at least 1,000,000 Shares, and (ii) the
Company has notified the Investors in writing that it is no longer accepting
Agreements from Investors for the purchase of Shares. Neither the Company nor
the Current Stockholder may enter into any Agreements after the Subscription
Date.

      3. Delivery of the Shares at Closing. The completion of the purchase and
sale of the Shares (the "Closing") shall occur (the "Closing Date") on ________
__, 2000, at the offices of the Company's counsel. At the Closing, the Company
shall deliver to the Investor one or more stock certificates representing the
number of Shares set forth on the signature page hereto, each such certificate
to be registered in the name of the Investor or, if so indicated on the
signature page hereto, in the name of a nominee designated by the Investor.

      The Company's obligation to issue and sell, and the Current Stockholder's
obligation to sell, the Shares to the Investor shall be subject to the following
conditions, any one or more of which may be waived by the Company on behalf of
itself and the Current Stockholder: (a) receipt by the Company of a certified or
official bank check or wire transfer of funds in the full amount of the purchase
price for the Shares being purchased hereunder as set forth on the signature
page hereto; (b) completion of the purchases and sales under the Agreements with
the Other Investors; and (c) the accuracy of the representations and warranties
made by the Investors and the fulfillment of those undertakings of the Investors
to be fulfilled prior to the Closing.

      The Investor's obligation to purchase the Shares shall be subject to the
following conditions, any one or more of which may be waived by the Investor:
(a) Investors shall have executed Agreements for the purchase of at least
1,000,000 Shares, (b) the representations and warranties of the Company and the
Current Stockholder set forth herein shall be true and correct as of the Closing
Date in all material respects and (c) the Investor shall have received such
closing documents as such Investor shall reasonably have requested, including, a
standard opinion of Company Counsel as to the matters set forth in Section 4A.2
and as to exemption from the registration requirements of the Securities Act of
1933, as amended (the "Securities Act"), of the sale of the Shares and a
standard opinion of Current Stockholder's counsel as to the matters set forth in
Sections 4B.2.


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      4A. Representations, Warranties and Covenants of the Company. The Company
hereby represents and warrants to, and covenants with, the Investor, as follows:

            4A.1 Organization. The Company is duly organized and validly
existing in good standing under the laws of the jurisdiction of its
organization. Each of the Company and its Subsidiaries (as defined in Rule 405
under the Securities Act) has full power and authority to own, operate and
occupy its properties and to conduct its business as presently conducted and as
described in the documents (the "Exchange Act Documents") filed by the Company,
as of the date hereof, under the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), and is registered or qualified to do business and in good
standing in each jurisdiction in which it owns or leases property or transacts
business and where the failure to be so qualified would have a material adverse
effect upon the business, financial condition, properties or operations of the
Company and its Subsidiaries, considered as one enterprise, and 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.

            4A.2 Due Authorization and Valid Issuance. The Company has all
requisite power and authority to execute, deliver and perform its obligations
under the Agreements, and the Agreements have been duly authorized and validly
executed and delivered by the Company and constitute legal, valid and binding
agreements of the Company enforceable against the Company in accordance with
their terms, except as rights to indemnity and contribution may be limited by
state or federal securities laws or the public policy underlying such laws,
except as enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws affecting creditors' and contracting
parties' rights generally and except as enforceability may be subject to general
principles of equity (regardless of whether such enforceability is considered in
a proceeding in equity or at law). The Shares being purchased by the Investor
hereunder have been or will be, upon issuance pursuant to the terms hereof, duly
authorized, validly issued, fully-paid and nonassessable.

            4A.3 Non-Contravention. The execution and delivery of the
Agreements, the issuance and sale of the Shares under the Agreements, the
fulfillment of the terms of the Agreements and the consummation of the
transactions contemplated thereby will not (A) conflict with or constitute a
material violation of, or material default (with the passage of time or
otherwise) under, (i) any material bond, debenture, note or other evidence of
indebtedness, lease, contract, indenture, mortgage, deed of trust, loan
agreement, joint venture or other agreement or instrument to which the Company
or any Subsidiary is a party or by which it or any of its Subsidiaries or their
respective properties are bound, (ii) the charter, by-laws or other
organizational documents of the Company or any Subsidiary, or (iii) any law,
administrative regulation, ordinance or order of any court or governmental
agency, arbitration panel or authority applicable to the Company or any
Subsidiary or their respective properties, or (B) result in the creation or
imposition of any material lien, encumbrance, claim, security interest or
restriction upon any of the material properties or material assets of the
Company or any Subsidiary or an acceleration of any material indebtedness
pursuant to any obligation, agreement or condition contained in any material
bond, debenture, note or any other evidence of indebtedness or any material
indenture, mortgage, deed of trust or any other agreement or instrument to which
the Company or any Subsidiary is a party or by which any of them is bound or to
which any of the property or assets of the Company or any Subsidiary is subject.
No consent, approval, authorization or other order of, or registration,
qualification or filing with, any regulatory body, administrative agency, or
other governmental body in the United States or any other person is required for
the execution and delivery of the Agreements and the valid issuance and sale of
the Shares to be sold pursuant to the Agreements by the Company, other than such
as have been made or obtained, and except for any post-closing securities
filings or notifications required to be made under federal or state securities
laws.

            4A.4 Capitalization. The capitalization of the Company as of June
30, 2000 is as set forth in the Exchange Act Documents. The Company has not
issued any capital stock since that date other than pursuant to (i) employee
benefit plans disclosed in the Exchange Act Documents, or (ii) outstanding
warrants or options or other securities disclosed in the Exchange Act Documents.
The Shares to be sold pursuant to the Agreements have been duly authorized, and
when issued and paid for in accordance with the terms of the Agreements will be
duly and validly issued, fully paid and nonassessable. The outstanding shares of
capital stock of the Company have been duly and validly issued and are fully
paid and nonassessable, have been issued in compliance with all federal and
state securities laws, and were not issued in violation of any preemptive rights
or similar rights to subscribe for or purchase securities.


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Except as set forth in or contemplated by the Exchange Act Documents, there are
no outstanding rights (including, without limitation, preemptive rights),
warrants or options to acquire, or instruments convertible into or exchangeable
for, any unissued shares of capital stock or other equity interest in the
Company or any Subsidiary, or any contract, commitment, agreement, understanding
or arrangement of any kind to which the Company is a party or of which the
Company has knowledge and relating to the issuance or sale of any capital stock
of the Company or any Subsidiary, any such convertible or exchangeable
securities or any such rights, warrants or options other than (i) shares of
ImmGenics Pharmaceuticals Inc. ("ImmGenics") that will become exchangeable into
a number of shares of Common Stock of the Company ("Conversion Stock") that
equals approximately US$77 million divided by the average trading price of the
Common Stock of the Company for the five days immediately preceding the
effective date of the registration statement covering the Conversion Stock; and
(ii) the Conversion Stock. Without limiting the foregoing, no preemptive right,
co-sale right, right of first refusal, registration right, or other similar
right exists with respect to the Company Shares or the issuance and sale
thereof, or pursuant to an agreement to which the Company is a party or the
Company's organizational documents, with respect to the Current Stockholder
Shares or the sale thereof other than those with respect to which waivers will
have been obtained prior to, and be in effect at, the Closing. No further
approval or authorization of any stockholder, the Board of Directors of the
Company or others is required for the issuance and sale of the Shares. The
Company owns the entire equity interest in each of its Subsidiaries, free and
clear of any pledge, lien, security interest, encumbrance, claim or equitable
interest, other than as described in the Exchange Act Documents. Except as
disclosed in the Exchange Act Documents, there are no stockholders agreements,
voting agreements or other similar agreements with respect to the Common Stock
to which the Company is a party or, to the knowledge of the Company, between or
among any of the Company's stockholders. For purposes of this Annex I,
"knowledge" means facts that are known to the person or which could have been
known to the person upon reasonable inquiry.

            4A.5 Legal Proceedings. There is no material legal or governmental
proceeding pending or, to the knowledge of the Company, threatened to which the
Company or any Subsidiary is or may be a party or of which the business or
property of the Company or any Subsidiary is subject that is not disclosed in
the Exchange Act Documents.

            4A.6 No Violations. Neither the Company nor any Subsidiary is in
violation of its charter, bylaws, or other organizational documents, or in
material violation of any law, administrative regulation, ordinance or order of
any court or governmental agency, arbitration panel or authority applicable to
the Company or any Subsidiary, which violation, individually or in the
aggregate, would be reasonably likely to have a material adverse effect on the
business or financial condition of the Company and its Subsidiaries, considered
as one enterprise, or is in default (and there exists no condition which, with
the passage of time or otherwise, would constitute a default) in any material
respect in the performance of any bond, debenture, note or any other evidence of
indebtedness in any indenture, mortgage, deed of trust or any other material
agreement or instrument to which the Company or any Subsidiary is a party or by
which the Company or any Subsidiary is bound or by which the properties of the
Company or any Subsidiary are bound, which would be reasonably likely to have a
material adverse effect upon the business or financial condition of the Company
and its Subsidiaries, considered as one enterprise.

            4A.7 Governmental Permits, Etc. With the exception of the matters
which are dealt with separately in Sections 4A.1, 4A.12, 4A.13, and 4A.14, each
of the Company and its Subsidiaries has all necessary franchises, licenses,
certificates and authorizations from any foreign, federal, state or local
government or governmental agency, department, or body that are currently
necessary for the operation of the business of the Company and its Subsidiaries
as currently conducted and as described in the Exchange Act Documents except
where the failure to currently possess could not reasonably be expected to have
a material adverse effect.

            4A.8 Intellectual Property. Except as, and to the extent,
specifically disclosed in the Exchange Act Documents (i) each of the Company and
its Subsidiaries owns or possesses rights to use all material patents, patent
rights, trademarks, copyrights, licenses, inventions, trade secrets, trade names
and know-how (collectively, "Intellectual Property") described or referred to in
the Exchange Act Documents as owned or possessed by it or that are necessary for
the conduct of its business as now conducted or as proposed to be conducted as
described in the Exchange Act Documents except where the failure to currently
own or possess would not have a material adverse effect on the condition
(financial or otherwise), earnings, operations or business of the Company and
its Subsidiaries considered as one enterprise, (ii) neither the Company nor any
of its Subsidiaries has received any notice of, or has any knowledge of,


                                      -5-
<PAGE>

any infringement of asserted rights of a third party with respect to any
Intellectual Property that, individually or in the aggregate, could reasonably
be expected to have a material adverse effect on the financial condition or
business of the Company and its Subsidiaries considered as one enterprise and
(iii) neither the Company nor any of its Subsidiaries has received any notice of
any infringement of rights of a third party with respect to any Intellectual
Property that, individually or in the aggregate, would have a material adverse
effect upon the business or financial condition of the Company and its
Subsidiaries, considered as one enterprise.

            4A.9 Financial Statements. The financial statements of the Company
and the related notes contained in the Exchange Act Documents present fairly, in
accordance with generally accepted accounting principles, the financial position
of the Company and its Subsidiaries as of the dates indicated, and the results
of its operations and cash flows for the periods therein specified. Such
financial statements (including the related notes) have been prepared in
accordance with generally accepted accounting principles applied on a consistent
basis throughout the periods therein specified, except as disclosed in the
Exchange Act Documents. The other financial information contained in the
Exchange Act Documents has been prepared on a basis consistent with the
financial statements of the Company.

            4A.10 No Material Adverse Change. Except as disclosed in the
Exchange Act Documents, since June 30, 2000, there has not been (i) any material
adverse change in the financial condition or earnings of the Company and its
Subsidiaries considered as one enterprise nor has any material adverse event
occurred to the Company or its Subsidiaries, (ii) any material adverse event
affecting the Company, (iii) any obligation, direct or contingent, that is
material to the Company and its Subsidiaries considered as one enterprise,
incurred by the Company, except obligations incurred in the ordinary course of
business, (iv) any dividend or distribution of any kind declared, paid or made
on the capital stock of the Company or any of its Subsidiaries, or (v) any loss
or damage (whether or not insured) to the physical property of the Company or
any of its Subsidiaries which has 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.

            4A.11 Disclosure. The information contained in the Exchange Act
Documents as of the date hereof and as of the Closing Date, did not and shall
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.

            4A.12 NASDAQ Compliance. The Company's Common Stock is registered
pursuant to Section 12(g) of the Exchange Act and is listed on The Nasdaq Stock
Market, Inc. National Market (the "Nasdaq National Market"), and the Company has
taken no action designed to, or likely to have the effect of, terminating the
registration of the Common Stock under the Exchange Act or de-listing the Common
Stock from the Nasdaq National Market, nor has the Company received any
notification that the Securities and Exchange Commission (the "SEC") or the
National Association of Securities Dealers, Inc. ("NASD") is contemplating
terminating such registration or listing.

            4A.13 Reporting Status. The Company has filed in a timely manner all
documents that the Company was required to file under the Exchange Act during
the 12 months preceding the date of this Agreement other than the failure to
timely file a report on Form 8-K, which was due on or around January 15, 2000
and which was filed on or around January 28, 2000. The following documents
complied in all material respects with the SEC's requirements as of their
respective filing dates, and the information contained therein as of the date
thereof did 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 where they were made not
misleading:

                  (a)   the current report on Form 8-K filed on or around
                        October 19, 2000;
                  (b)   the registration statement on Form S-8 filed on or
                        around September 8, 2000;
                  (c)   the quarterly report on Form 10-Q for the quarterly
                        period ended June 30, 2000 filed on or around August 14,
                        2000;
                  (d)   the proxy statement pursuant to Section 14(a) of the
                        Exchange Act, filed on or around July 17, 2000;


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                  (e)   the quarterly report on Form 10Q for the quarterly
                        period ended March 31, 2000 filed on or around May 15,
                        2000;
                  (f)   the proxy statement pursuant to Section 14(a) of the
                        Exchange Act filed on or around March 31, 2000;
                  (g)   the annual report on Form 10-K for the year ended
                        December 31, 1999 filed on or around March 28, 2000;
                  (h)   the proxy statement pursuant to Section 14(a) of the
                        Exchange Act filed on or around March 21, 2000;
                  (i)   the current report on Form 8-K filed on or around March
                        2 ,2000;
                  (j)   amendment no. 1 to the registration statement on Form
                        S-1 filed on or around February 10, 2000;
                  (k)   the current report on Form 8-K filed on or around
                        January 28, 2000;
                  (l)   the current report on Form 8-K filed on or around
                        January 28, 2000;
                  (m)   the registration statement on Form S-1 filed on or
                        around January 28, 2000;
                  (n)   amendment no. 1 to Form 8-A filed on or around November
                        30, 1999;
                  (o)   the registration statement on Form S-3 filed on or
                        around November 26, 1999;
                  (p)   the current report on Form 8-K filed on or around
                        November 23, 1999;
                  (q)   the quarterly report on Form 10-Q for the quarterly
                        period ended September 30, 1999 filed on or around
                        November 12, 1999;
                  (r)   the registration statement on Form S-8 filed on or
                        around November 10, 1999; and
                  (s)   all other documents, if any, filed by the Company with
                        the SEC since October 19, 2000 pursuant to the reporting
                        requirements of the Exchange Act.

            4A.14 Listing. The Company shall comply with all requirements of the
National Association of Securities Dealers, Inc. with respect to the issuance of
the Company Shares and the listing of the Shares on the Nasdaq National Market.

            4A.15 No Manipulation of Stock. The Company has not taken and will
not, in violation of applicable law, take, any action designed to or that might
reasonably be expected to cause or result in stabilization or manipulation of
the price of the Common Stock to facilitate the sale or resale of the Shares.

            4A.16 Company not an "Investment Company". The Company has been
advised of the rules and requirements under the Investment Company Act of 1940,
as amended (the "Investment Company Act"). The Company is not, and immediately
after receipt of payment for the Company Shares will not be, an "investment
company" or an entity "controlled" by an "investment company" within the meaning
of the Investment Company Act and will conduct its business in a manner so that
it will not become subject to the Investment Company Act.

      4B. Representations and Warranties of the Current Stockholder. The Current
Stockholder represents and warrants to and covenants with, the Investor, as
follows:

            4B.1 Organization. The Current Stockholder is duly organized and
validly existing in good standing under the laws of the jurisdiction of its
organization.

            4B.2 Due Authorization and Valid Issuance. The Current Stockholder
has all requisite power and authority to execute, deliver and perform its
obligations under the Agreements and the Power of Attorney appointing certain
individuals named therein as the Current Stockholder's attorneys-in-fact to the
extent set forth therein relating to the transactions contemplated hereby (the
"Power of Attorney"), and the Agreements and the Power of Attorney have been
duly authorized and validly executed and delivered by the Current Stockholder
and constitute legal, valid and binding agreements of the Current Stockholder
enforceable against the Current Stockholder in accordance with their terms,
except as rights to indemnity and contribution may be limited by state or
federal securities laws or the public policy underlying such laws, except as
enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws affecting creditors' and contracting
parties' rights generally and except as


                                      -7-
<PAGE>

enforceability may be subject to general principles of equity (regardless of
whether such enforceability is considered in a proceeding in equity or at law).

            4B.3 Non-Contravention. The execution and delivery of the Agreements
and the Power of Attorney, the sale of the Current Stockholder Shares under the
Agreements, the fulfillment of the terms of the Agreements and the Power of
Attorney and the consummation of the transactions contemplated thereby will not
(A) conflict with or constitute a material violation of, or material default
(with the passage of time or otherwise) under, (i) any material bond, debenture,
note or other evidence of indebtedness, lease, contract, indenture, mortgage,
deed of trust, loan agreement, joint venture or other agreement or instrument to
which the Current Stockholder or any Subsidiary is a party or by which it or any
of its Subsidiaries or their respective properties are bound, (ii) the charter,
by-laws or other organizational documents of the Current Stockholder or any
Subsidiary, or (iii) any law, administrative regulation, ordinance or order of
any court or governmental agency, arbitration panel or authority applicable to
the Current Stockholder or any Subsidiary or their respective properties, or (B)
result in the creation or imposition of any material lien, encumbrance, claim,
security interest or restriction upon any of the material properties or material
assets of the Current Stockholder or any Subsidiary or an acceleration of any
material indebtedness pursuant to any obligation, agreement or condition
contained in any material bond, debenture, note or any other evidence of
indebtedness or any material indenture, mortgage, deed of trust or any other
agreement or instrument to which the Current Stockholder or any Subsidiary is a
party or by which any of them is bound or to which any of the property or assets
of the Current Stockholder or any Subsidiary is subject. No consent, approval,
authorization or other order of, or registration, qualification or filing with,
any regulatory body, administrative agency, or other governmental body in the
United States or any other person is required for the execution and delivery of
the Agreements or the Power of Attorney and the valid issuance and sale of the
Current Stockholder Shares to be sold pursuant to the Agreements, other than
such as have been made or obtained, and except for any post-closing securities
filings or notifications required to be made under federal or state securities
laws.

            4B.4 Required Consents and Approvals. No preemptive right, co-sale
right, right of first refusal, registration right, or other similar right exists
with respect to the Current Stockholder Shares or the sale thereof, other than
any such rights which have been duly and validly waived. No further approval or
authorization of any stockholder, the Board of Directors of the Current
Stockholder or others is required for the sale of the Current Stockholder
Shares.

            4B.5 No Manipulation of Stock. The Current Stockholder has not taken
and will not, in violation of applicable law, take, any action designed to or
that might reasonably be expected to cause or result in stabilization or
manipulation of the price of the Common Stock to facilitate the sale or resale
of the Shares.

            4B.6 Title to Shares to be Sold. The Current Stockholder is the
lawful owner of the Current Stockholder Shares and upon sale and delivery of,
and payment for, such Current Stockholder Shares as provided herein, the Current
Stockholder will convey good and marketable title to such Current Stockholder
Shares, free and clear of all liens, encumbrances, equities and claims
whatsoever.

            4B.7 Confirmation. An officer of the Current Stockholder who is
familiar with the Company has reviewed the Exchange Act Documents. The Current
Stockholder, without having made any independent check or verification except as
described herein, (i) has no knowledge of any material fact, condition or
information not disclosed in the Exchange Act Documents which has had or may
reasonably be expected to result in a material adverse change in the condition,
financial or otherwise, or in the earnings, business, operation or prospects,
whether or not arising from transactions in the ordinary course of business of
the Company and its subsidiaries, considered as one entity, and (ii) is not
prompted to sell the Current Stockholder Shares by any information concerning
the Company which is not set forth in the Exchange Act Documents.

      5. Representations, Warranties and Covenants of the Investor.

            5.1 The Investor represents and warrants to, and covenants with, the
Company and the Current Stockholder that: (i) the Investor is an institutional
"accredited investor" as defined in paragraphs (1), (2), (3) or (7) of
subsection (a) of Rule 501 under the Securities Act and the Investor is also
knowledgeable, sophisticated and


                                      -8-
<PAGE>

experienced in making, and is qualified to make decisions with respect to
investments in shares presenting an investment decision like that involved in
the purchase of the Shares, including investments in securities issued by the
Company and investments in comparable companies, and has requested, received,
reviewed and considered all information it deemed relevant in making an informed
decision to purchase the Shares; (ii) the Investor is acquiring the number of
Shares set forth on the signature page hereto in the ordinary course of its
business and for its own account for investment only and with no present
intention of distributing any of such Shares or any arrangement or understanding
with any other persons regarding the distribution of such Shares; (iii) the
Investor will not, directly or indirectly, offer, sell, pledge, transfer or
otherwise dispose of (or solicit any offers to buy, purchase or otherwise
acquire or take a pledge of) any of the Shares except in compliance with the
Securities Act, applicable state securities laws and the respective rules and
regulations promulgated thereunder; (iv) the Investor has answered all questions
on the Investor Questionnaire hereto for use in preparation of the Registration
Statement and the answers thereto are true, correct and complete as of the date
hereof and will be true, correct and complete as of the Closing Date; (v) the
Investor will notify the Company immediately of any change in any of such
information until such time as the Investor has sold all of its Shares or until
the Company is no longer required to keep the Registration Statement effective;
and (vi) the Investor has, in connection with its decision to purchase the
number of Shares set forth on the signature page hereto, relied only upon the
Exchange Act Documents and the representations and warranties of the Company and
the Current Stockholder contained herein. Investor understands that its
acquisition of the Shares has not been registered under the Securities Act or
registered or qualified under any state securities law in reliance on specific
exemptions therefrom, which exemptions may depend upon, among other things, the
bona fide nature of the Investor's investment intent as expressed herein.
Investor has completed or caused to be completed and delivered to the Company
the Investor Questionnaire attached as Exhibit B to the Exchange Act Documents,
which questionnaire is true, correct and complete in all material respects.

            5.2 The Investor acknowledges, represents and agrees that no action
has been or will be taken in any jurisdiction outside the United States by the
Company that would permit an offering of the Shares, or possession or
distribution of offering materials in connection with the issue of the Shares,
in any jurisdiction outside the United States where legal action by the Company
for that purpose is required. Each Investor outside the United States will
comply with all applicable laws and regulations in each foreign jurisdiction in
which it purchases, offers, sells or delivers Shares or has in its possession or
distributes any offering material, in all cases at its own expense.

            5.3 The Investor hereby covenants with the Company not to make any
sale of the Shares without complying with the provisions of this Agreement and
without causing the prospectus delivery requirement under the Securities Act to
be satisfied, and the Investor acknowledges that the certificates evidencing the
Shares will be imprinted with a legend that prohibits their transfer except in
accordance therewith. The Investor acknowledges that there may occasionally be
times when the Company determines that it must suspend the use of the Prospectus
forming a part of the Registration Statement, as set forth in Section 7.2(c).

            5.4 The Investor further represents and warrants to, and covenants
with, the Company and the Current Stockholder that (i) the Investor has full
right, power, authority and capacity to enter into this Agreement and to
consummate the transactions contemplated hereby and has taken all necessary
action to authorize the execution, delivery and performance of this Agreement,
and (ii) this Agreement constitutes a valid and binding obligation of the
Investor enforceable against the Investor in accordance with its terms, except
as enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws affecting creditors' and contracting
parties' rights generally and except as enforceability may be subject to general
principles of equity (regardless of whether such enforceability is considered in
a proceeding in equity or at law) and except as the indemnification agreements
of the Investors herein may be legally unenforceable.

            5.5 Investor will not use any of the restricted Shares acquired
pursuant to this Agreement to cover any short position in the Common Stock of
the Company if doing so would be in violation of applicable securities laws.

            5.6 The Investor understands that nothing in the Exchange Act
Documents, this Agreement or any other materials presented to the Investor in
connection with the purchase and sale of the Shares constitutes legal, tax or
investment advice. The Investor has consulted such legal, tax and investment
advisors as it, in its sole discretion, has deemed necessary or appropriate in
connection with its purchase of Shares.


                                      -9-
<PAGE>

      6. Survival of Representations, Warranties and Agreements. Notwithstanding
any investigation made by any party to this Agreement, all covenants,
agreements, representations and warranties made by the Company, the Current
Stockholder and the Investor herein shall survive the execution of this
Agreement, the delivery to the Investor of the Shares being purchased and the
payment therefor. Without limiting the foregoing, the parties hereto acknowledge
that the representations and warranties contained herein are made solely as of
the date hereof and, other than at the Closing Date, there is no obligation to
update any such representations and warranties.

      7. Registration of the Shares; Compliance with the Securities Act.

            7.1 Registration Procedures and Other Matters. The Company shall:

                   (a) subject to receipt of necessary information from the
Investors after prompt request from the Company to the Investors to provide such
information, use best efforts to prepare and file with the SEC, within 10
business days after the Closing Date, a registration statement on Form S-1 (the
"S-1 Registration Statement") to enable the resale of the Shares by the
Investors from time to time through the automated quotation system of the Nasdaq
National Market or in privately-negotiated transactions;

                   (b) use best efforts to cause the S-1 Registration Statement
to become effective within 30 days after the S-1 Registration Statement is filed
by the Company, such efforts to include, without limiting the generality of the
foregoing, preparing and filing with the SEC in such 30-day period any financial
statements that are required to be filed prior to the effectiveness of such S-1
Registration Statement;

                   (c) subject to receipt of necessary information from the
Investors after prompt request from the Company to the Investors to provide such
information, use best efforts to prepare and file with the SEC, within 10 days
after the Company first becomes eligible to file a registration statement on
Form S-3, a registration statement on Form S-3 (the "S-3 Registration
Statement") to enable the resale of the Shares by the Investors from time to
time through the automated quotation system of the Nasdaq National Market or in
privately-negotiated transactions; and to use best efforts to cause the S-3
Registration Statement to become effective as soon as practicable thereafter,
such efforts to include, without limiting the generality of the foregoing,
preparing and filing with the SEC as promptly as practicable any financial
statements that are required to be filed prior to the effectiveness of such S-3
Registration Statement (the term "Registration Statement" shall mean the S-1
Registration Statement until the S-3 Registration Statement is first declared
effective by the SEC, after which time it shall mean the S-3 Registration
Statement);

                   (d) use best efforts to prepare and file with the SEC such
amendments and supplements to the Registration Statement and the Prospectus used
in connection therewith as may be necessary to keep the Registration Statement
current, effective and free from any material misstatement or omission to state
a material fact for a period not exceeding, with respect to each Investor's
Shares purchased hereunder, the earlier of (i) the second anniversary of the
Closing Date, (ii) the date on which the Investor may sell all Shares then held
by the Investor without restriction by the volume limitations of Rule 144(e) of
the Securities Act, or (iii) such time as all Shares purchased by such Investor
in this Offering have been sold pursuant to a registration statement.

                   (e) furnish to the Investor with respect to the Shares
registered under the Registration Statement such number of copies of the
Registration Statement, Prospectuses and Preliminary Prospectuses in conformity
with the requirements of the Securities Act and such other documents as the
Investor may reasonably request (which shall not include confidential material),
in furtherance of the Investor's proposed public sale or other disposition of
all or any of the Shares by the Investor; provided, however, that the obligation
of the Company to deliver copies of Prospectuses or Preliminary Prospectuses to
the Investor shall be subject to the receipt by the Company of reasonable
assurances from the Investor that the Investor will comply with the applicable
provisions of the Securities Act and of such other securities or blue sky laws
as may be applicable in connection with any use of such Prospectuses or
Preliminary Prospectuses;


                                      -10-
<PAGE>

                   (f) file documents required of the Company for normal blue
sky clearance in states in the United States specified in writing by the
Investor; provided, however, that the Company shall not be required to qualify
to do business or consent to service of process in any jurisdiction in which it
is not now so qualified or has not so consented;

                   (g) bear all reasonable expenses in connection with the
procedures in paragraph (a) through (f) of this Section 7.1 and the registration
of the Shares pursuant to the Registration Statement; and

                   (h) advise the Investor, promptly after it shall receive
notice or obtain knowledge of the issuance of any stop order by the SEC delaying
or suspending the effectiveness of the Registration Statement or of the
initiation or threat of any proceeding for that purpose; and it will promptly
use its best efforts to prevent the issuance of any stop order or to obtain its
withdrawal at the earliest possible moment if such stop order should be issued.

      Notwithstanding anything to the contrary herein, the Registration
Statement shall cover only the Shares. In no event at any time before the
Registration Statement with respect to the Shares is filed with the SEC shall
the Company file any other registration statement without the prior written
consent of a majority in interest of the Investors.

      The Company understands that the Investor disclaims being an underwriter,
but the Investor being deemed an underwriter by the SEC shall not relieve the
Company of any obligations it has hereunder; provided, however that if the
Company receives notification from the SEC that the Investor is deemed an
underwriter, then the period by which the Company is obligated to submit an
acceleration request to the SEC shall be extended to the earlier of (i) the 90th
day after such SEC notification, or (ii) 120 days after the initial filing of
the Registration Statement with the SEC.

            7.2 Transfer of Shares After Registration; Suspension.

                   (a) The Investor agrees that it will not effect any
disposition of the Shares or its right to purchase the Shares that would
constitute a sale within the meaning of the Securities Act except as
contemplated in the Registration Statement referred to in Section 7.1 and as
described below or as otherwise permitted by law, and that it will promptly
notify the Company of any changes in the information set forth in the
Registration Statement regarding the Investor or its plan of distribution.

                   (b) Except in the event that paragraph (c) below applies, the
Company shall (i) if deemed necessary by the Company, prepare and file from time
to time with the SEC a post-effective amendment to the Registration Statement or
a supplement to the related Prospectus or a supplement or amendment to any
document incorporated therein by reference or file any other required document
so that such Registration Statement 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 not misleading, and so that, as
thereafter delivered to purchasers of the Shares 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; (ii) provide the Investor copies of any documents filed pursuant
to Section 7.2(b)(i); and (iii) inform each Investor that the Company has
complied with its obligations in Section 7.2(b)(i) (or that, if the Company has
filed a post-effective amendment to the Registration Statement which has not yet
been declared effective, the Company will notify the Investor to that effect,
will use best efforts to secure the effectiveness of such post-effective
amendment as promptly as reasonably practicable and will promptly notify the
Investor pursuant to Section 7.2(b)(i) hereof when the amendment has become
effective).

                   (c) Subject to paragraph (d) below, in the event (i) 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; (ii) 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; or
(iii) 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
Shares for sale in any jurisdiction or the initiation or threatening of any
proceeding for such purpose; or (iv) of any event or


                                      -11-
<PAGE>

circumstance which, upon the advice of its counsel, necessitates the making of
any changes in the Registration Statement or Prospectus, or any document
incorporated or deemed to be incorporated therein by reference, so that, in the
case of the Registration Statement, it will not contain any untrue statement of
a material fact or any omission to state a 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 any omission to state 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; then the Company
shall, deliver a certificate in writing to the Investor (the "Suspension
Notice") to the effect of the foregoing and, upon receipt of such Suspension
Notice, the Investor will refrain from selling any Shares pursuant to the
Registration Statement (a "Suspension") until the Investor's receipt of copies
of a supplemented or amended Prospectus prepared and filed by the Company, or
until it is advised in writing by the Company that the current Prospectus may be
used, and has received copies of any additional or supplemental filings that are
incorporated or deemed incorporated by reference in any such Prospectus. In the
event of any Suspension, the Company will use its best efforts to cause the use
of the Prospectus so suspended to be resumed as soon as reasonably practicable
within 20 business days after the delivery of a Suspension Notice to the
Investor. In addition to and without limiting any other remedies (including,
without limitation, at law or at equity) available to the Investor, the Investor
shall be entitled to specific performance in the event that the Company fails to
comply with the provisions of this Section 7.2(c).

                   (d) Notwithstanding the foregoing paragraphs of this Section
7.2, the Investor shall not be prohibited from selling Shares under the
Registration Statement as a result of Suspensions for more than 60 days in the
aggregate during any twelve month period, unless, in the good faith judgment of
the Company's Board of Directors, upon advice of counsel, the sale of Shares
under the Registration Statement in reliance on this paragraph 7.2(d) would be
reasonably likely to cause a violation of the Securities Act or the Exchange
Act.

                   (e) Provided that a Suspension is not then in effect, the
Investor may sell Shares under the Registration Statement, provided that it
arranges for delivery of a current Prospectus to the transferee of such Shares.
Upon receipt of a request therefor, the Company has agreed to provide an
adequate number of current Prospectuses to the Investor and to supply copies to
any other parties requiring such Prospectuses.

                   (f) In the event of a sale of Shares by the Investor pursuant
to the Registration Statement, the Investor must also deliver to the Company's
transfer agent, with a copy to the Company, a Certificate of Subsequent Sale
substantially in the form attached hereto as Exhibit A, so that the Shares may
be properly transferred.

            7.3 Indemnification. For the purpose of this Section 7.3:

            (i) the term "Selling Stockholder" shall include the Investor and
any affiliate of such Investor;

            (ii) the term "Registration Statement" shall include any final
Prospectus, exhibit, supplement or amendment included in or relating to the
Registration Statement referred to in Section 7.1; and

            (iii) the term "untrue statement" shall include any untrue statement
or alleged untrue statement, or any omission or alleged omission to state in the
Registration Statement 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.

                   (a) The Company agrees to indemnify and hold harmless each
Selling Stockholder from and against any losses, claims, damages or liabilities
to which such Selling Stockholder may become subject (under the Securities Act
or otherwise) insofar as such losses, claims, damages or liabilities (or actions
or proceedings in respect thereof) arise out of, or are based upon (i) any
untrue statement of a material fact contained in the Registration Statement or
any omission of a material fact required to be stated therein or necessary to
make the statements therein not misleading, or (ii) any failure by the Company
to fulfill any undertaking included in the Registration Statement, and the
Company will reimburse such Selling Stockholder for any reasonable legal or
other expenses reasonably incurred in investigating, defending or preparing to
defend any such action, proceeding or claim, or preparing to defend any such
action, proceeding or claim, provided, however, that the Company shall not be
liable in any such case to the extent that such loss, claim, damage or liability
arises out of, or is based upon, an untrue statement made in such Registration


                                      -12-
<PAGE>

Statement or an omission of a material fact required to be stated therein or
necessary to make the statements therein not misleading in reliance upon and in
conformity with written information furnished to the Company by or on behalf of
such Selling Stockholder specifically for use in preparation of the Registration
Statement or the failure of such Selling Stockholder to comply with its
covenants and agreements contained in Section 7.2 hereof respecting sale of the
Shares or any statement or omission in any Prospectus that is corrected in any
subsequent Prospectus that was delivered to the Selling Stockholder prior to the
pertinent sale or sales by the Selling Stockholder. The Company shall reimburse
each Selling Stockholder for the amounts provided for herein on 30 days' notice
as such expenses are incurred.

                   (b) The Current Stockholder agrees to indemnify and hold
harmless the Company and each Selling Stockholder from and against any losses,
claims, damages or liabilities to which the Company or such Selling Stockholder
may become subject (under the Securities Act or otherwise) insofar as such
losses, claims, damages or liabilities (or actions or proceedings in respect
thereof) arise out of, or are based upon any untrue statement of a material fact
contained in the Registration Statement or any omission of a material fact
required to be stated therein or necessary to make the statements therein not
misleading to the extent, but only to the extent, that such untrue statement of
a material fact or such omission of a material fact required to be stated
therein or necessary to make the statements therein not misleading was made in
reliance upon and in conformity with written information furnished to the
Company (or a representative thereof) by the Current Stockholder directly or
through a representative of the Current Stockholder specifically for use in the
preparation thereof, and the Current Stockholder will reimburse such Selling
Stockholder for any reasonable legal or other expenses reasonably incurred in
investigating, defending or preparing to defend any such action, proceeding or
claim, or preparing to defend any such action, proceeding or claim, provided,
however, that the Current Stockholder shall not be liable to a Selling
Stockholder in any such case to the extent that such loss, claim, damage or
liability arises out of, or is based upon, an untrue statement or omission in
any Prospectus that is corrected in any subsequent Prospectus that was delivered
to the Selling Stockholder prior to the pertinent sale or sales by the Selling
Stockholder and provided further that the Current Stockholder's obligation to
indemnify the Selling Stockholders shall be limited to the amount received by
the Current Stockholder from the sale of the Current Stockholder Shares
hereunder. Subject to the foregoing limitation on the amount of the Current
Stockholder's indemnity obligation, the Current Stockholder shall reimburse each
Selling Stockholder for the amounts provided for herein on 30 days' notice as
such expenses are incurred.

                   (c) The Investor agrees to indemnify and hold harmless the
Company and the Current Stockholder (and each person, if any, who controls the
Company or the Current Stockholder within the meaning of Section 15 of the
Securities Act, each officer of the Company who signs the Registration Statement
and each director of the Company) from and against any losses, claims, damages
or liabilities to which the Company or the Current Stockholder (or any such
officer, director or controlling person) may become subject (under the
Securities Act or otherwise), insofar as such losses, claims, damages or
liabilities (or actions or proceedings in respect thereof) arise out of, or are
based upon, (i) any failure to comply with the covenants and agreements
contained in Section 7.2 hereof respecting sale of the Shares, or (ii) any
untrue statement of a material fact contained in the Registration Statement or
any omission of a material fact required to be stated therein or necessary to
make the statements therein not misleading if such untrue statement or such
omission of a material fact required to be stated therein or necessary to make
the statements therein not misleading was made in reliance upon and in
conformity with written information furnished by or on behalf of the Investor
specifically for use in preparation of the Registration Statement, and the
Investor will reimburse the Company (or such officer, director or controlling
person) and the Current Stockholder (or such officer, director or controlling
person), as the case may be, for any legal or other expenses reasonably incurred
in investigating, defending or preparing to defend any such action, proceeding
or claim; provided that the Investor's obligation to indemnify the Company shall
be limited to the net amount received by the Investor from the sale of the
Shares.

                   (d) Promptly after receipt by any indemnified person of a
notice of a claim or the beginning of any action in respect of which indemnity
is to be sought against an indemnifying person pursuant to this Section 7.3,
such indemnified person shall notify the indemnifying person in writing of such
claim or of the commencement of such action, but the omission to so notify the
indemnifying party will not relieve it from any liability which it may have to
any indemnified party under this Section 7.3 (except to the extent that such
omission materially and adversely affects the indemnifying party's ability to
defend such action) or from any liability otherwise than under this Section 7.3.
Subject to the provisions hereinafter stated, in case any such action shall be
brought against an


                                      -13-
<PAGE>

indemnified person, the indemnifying person shall be entitled to participate
therein, and, to the extent that it shall elect by written notice delivered to
the indemnified party promptly after receiving the aforesaid notice from such
indemnified party, shall be entitled to assume the defense thereof, with counsel
reasonably satisfactory to such indemnified person. After notice from the
indemnifying person to such indemnified person of its election to assume the
defense thereof, such indemnifying person shall not be liable to such
indemnified person for any legal expenses subsequently incurred by such
indemnified person in connection with the defense thereof, provided, however,
that if there exists or shall exist a conflict of interest that would make it
inappropriate, in the opinion of counsel to the indemnified person, for the same
counsel to represent both the indemnified person and such indemnifying person or
any affiliate or associate thereof, the indemnified person shall be entitled to
retain its own counsel at the expense of such indemnifying person; provided,
however, that no indemnifying person shall be responsible for the fees and
expenses of more than one separate counsel (together with appropriate local
counsel) for all indemnified parties. In no event shall any indemnifying person
be liable in respect of any amounts paid in settlement of any action unless the
indemnifying person shall have approved the terms of such settlement; provided
that such consent shall not be unreasonably withheld. No indemnifying person
shall, without the prior 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
includes an unconditional release of such indemnified person from all liability
on claims that are the subject matter of such proceeding.

                   (e) If the indemnification provided for in this Section 7.3
is unavailable to or insufficient to hold harmless an indemnified party under
subsection (a), (b) or (c) above in respect of any losses, claims, damages or
liabilities (or actions or proceedings in respect thereof) referred to therein,
then each indemnifying party shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims, damages or
liabilities (or actions in respect thereof) in such proportion as is appropriate
to reflect the relative fault of the Company and the Current Stockholder on the
one hand and the Investor, as well as any other Selling Shareholders under such
registration statement, on the other in connection with the statements or
omissions or other matters which resulted in such losses, claims, damages or
liabilities (or actions in respect thereof), as well as any other relevant
equitable considerations. The relative fault shall be determined by reference
to, among other things, in the case of an untrue statement, whether the untrue
statement relates to information supplied by the Company or the Current
Stockholder on the one hand or an Investor or other Selling Shareholder on the
other and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such untrue statement. The Company, the
Current Stockholder and the Investor agree that it would not be just and
equitable if contribution pursuant to this subsection (e) were determined by pro
rata allocation (even if the Investor and other Selling Shareholders were
treated as one entity for such purpose) or by any other method of allocation
which does not take into account the equitable considerations referred to above
in this subsection (e). The amount paid or payable by an indemnified party as a
result of the losses, claims, damages or liabilities (or actions in respect
thereof) referred to above in this subsection (e) shall be deemed to include any
legal or other expenses reasonably incurred by such indemnified party in
connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this subsection (e), (1) the Investor shall
not be required to contribute any amount in excess of the amount by which the
net amount received by the Investor from the sale of the Shares to which such
loss relates exceeds the amount of any damages which such Investor has otherwise
been required to pay by reason of such untrue statement and (2) the Current
Stockholder shall not be required to contribute any amount in excess of the
amount by which the amount received by the Current Stockholder from the sale of
the Current Stockholder Shares in the Offering exceeds the amount of any damages
which such Current Stockholder has otherwise been required to pay Investors by
reason of such untrue statement. 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 Investor's obligations in this subsection to
contribute shall be in proportion to its Investor sale of Shares to which such
loss relates and shall not be joint with any other Selling Shareholders.

                   (f) The parties to this Agreement hereby acknowledge that
they are sophisticated business persons who were represented by counsel during
the negotiations regarding the provisions hereof including, without limitation,
the provisions of this Section 7.3, and are fully informed regarding said
provisions. They further acknowledge that the provisions of this Section 7.3
fairly allocate the risks in light of the ability of the parties to investigate
the Company and its business in order to assure that adequate disclosure is made
in the Registration Statement as required by the Act and the Exchange Act. The
parties are advised that federal or state public policy as


                                      -14-
<PAGE>

interpreted by the courts in certain jurisdictions may be contrary to certain of
the provisions of this Section 7.3, and the parties hereto hereby expressly
waive and relinquish any right or ability to assert such public policy as a
defense to a claim under this Section 7.3 and further agree not to attempt to
assert any such defense.

            7.4 Termination of Conditions and Obligations. The conditions
precedent imposed by Section 5 or this Section 7 upon the transferability of the
Shares shall cease and terminate as to any particular number of the Shares when
such Shares shall have been effectively registered under the Securities Act and
sold or otherwise disposed of in accordance with the intended method of
disposition set forth in the Registration Statement covering such Shares or at
such time as an opinion of counsel satisfactory to the Company shall have been
rendered to the effect that such conditions are not necessary in order to comply
with the Securities Act.

            7.5 Information Available. So long as the Registration Statement is
effective covering the resale of Shares owned by the Investor, the Company will
furnish to the Investor:

                   (a) as soon as reasonably practicable after it is available,
one copy of (i) its Annual Report to Stockholders (which Annual Report shall
contain financial statements audited in accordance with generally accepted
accounting principles by a national firm of certified public accountants), (ii)
its Annual Report on Form 10-K and (iii) its Quarterly Reports on Form 10-Q (the
foregoing, in each case, excluding exhibits);

                   (b) upon the request of the Investor, all exhibits excluded
by the parenthetical to subparagraph (a) of this Section 7.5 as filed with the
SEC (excluding any unredacted version of an exhibit subject to a pending
confidential treatment request or an order granting such a request) and all
other information that is made available to shareholders; and

                   (c) upon the reasonable request of the Investor, an adequate
number of copies of the Prospectuses to supply to any other party requiring such
Prospectuses; and upon the reasonable request of the Investor, the President or
the Chief Financial Officer of the Company (or an appropriate designee thereof)
will meet with the Investor or a representative thereof at the Company's
headquarters to discuss all information relevant for disclosure in the
Registration Statement covering the Shares and will otherwise reasonably
cooperate with any Investor conducting an investigation for the purpose of
reducing or eliminating such Investor's exposure to liability under the
Securities Act, including the reasonable production of information at the
Company's headquarters; provided, that the Company shall not be required to
disclose any confidential information to or meet at its headquarters with any
Investor until and unless the Investor shall have entered into a confidentiality
agreement in form and substance reasonably satisfactory to the Company with the
Company with respect thereto.

      8. Notices. All notices, requests, consents and other communications
hereunder shall be in writing, shall be mailed (A) if within domestic United
States by first-class registered or certified airmail, or nationally recognized
overnight express courier, postage prepaid, or by facsimile, or (B) if delivered
from outside the United States, by International Federal Express or facsimile,
and shall be deemed given (i) if delivered by first-class registered or
certified mail domestic, three business days after so mailed, (ii) if delivered
by nationally recognized overnight carrier, one business day after so mailed,
(iii) if delivered by International Federal Express, two business days after so
mailed, (iv) if delivered by facsimile, upon electronic confirmation of receipt
and shall be delivered as addressed as follows:

            (a)   if to the Company, to:

                        Abgenix, Inc.
                        7601 Dumbarton Circle
                        Fremont, CA 94555
                        Attn: Chief Executive Officer


                                      -15-
<PAGE>

                   with a copy to:

                        O'Melveny & Myers LLP
                        Embarcadero Center West
                        275 Battery Street
                        San Francisco, CA 94111
                        Attn: Peter T. Healy, Esq.

            (b)   if to the Current Stockholder:

                        Cell Genesys, Inc.
                        342 Lakeside Drive
                        Foster City, CA 9404
                        Attn: Chief Executive Officer

                   with a copy to:

                        Wilson Sonsini Goodrich & Rosati
                        650 Page Mill Road
                        Palo Alto, CA 94304
                        Attn: Herbert P. Fockler, Esq.

            (b) if to the Investor, at its address on the signature page hereto,
or at such other address or addresses as may have been furnished to the Company
in writing.

      9. Changes. This Agreement may not be modified or amended except pursuant
to an instrument in writing signed by the Company, the Current Stockholder and
the Investor.

      10. Headings. The headings of the various sections of this Agreement have
been inserted for convenience of reference only and shall not be deemed to be
part of this Agreement.

      11. Severability. In case any provision contained in this Agreement should
be invalid, illegal or unenforceable in any respect, the validity, legality and
enforceability of the remaining provisions contained herein shall not in any way
be affected or impaired thereby.

      12. Governing Law. This Agreement shall be governed by, and construed in
accordance with, the internal laws of the State of Delaware, without giving
effect to the principles of conflicts of law.

      13. Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall constitute an original, but all of which, when
taken together, shall constitute but one instrument, and shall become effective
when one or more counterparts have been signed by each party hereto and
delivered to the other parties.

      14. Rule 144. The Company covenants that it will file the reports required
to be filed by it under the Securities Act and the Exchange Act and the rules
and regulations adopted by the SEC thereunder (or, if the Company is not
required to file such reports, it will, upon the request of any Investor holding
Shares purchased hereunder made after the first anniversary of the Closing Date,
make publicly available such information as necessary to permit sales pursuant
to Rule 144 under the Securities Act), and it will take such further action as
any such Investor may reasonably request, all to the extent required from time
to time to enable such Investor to sell Shares purchased hereunder without
registration under the Securities Act within the limitation of the exemptions
provided by (a) Rule 144 under the Securities Act, as such Rule may be amended
from time to time, or (b) any similar rule or regulation hereafter adopted by
the SEC. Upon the request of the Investor, the Company will deliver to such
holder a written statement as to whether it has complied with such information
and requirements.


                                      -16-
<PAGE>

      15. Confidential Information. The Investor represents to the Company that,
at all times during the Company's offering of the Shares, the Investor has
maintained in confidence all non-public information regarding the Company
received by the Investor from the Company or its agents, and covenants that it
will continue so maintain in confidence such information until such information
becomes generally publicly available other than through a violation of this
provision by the Investor or its agents.


                                      -17-
<PAGE>

                                  ABGENIX, INC.

                             INVESTOR QUESTIONNAIRE

                (ALL INFORMATION WILL BE TREATED CONFIDENTIALLY)

To: Abgenix, Inc.
    7601 Dumbarton Circle
    Fremont, CA 94555

      This Investor Questionnaire ("Questionnaire") must be completed by each
potential investor in connection with the offer and sale of the shares of the
common stock, par value $0.0001 per share, of Abgenix, Inc. (the "Securities").
The Securities are being offered and sold by Abgenix, Inc. (the "Corporation")
and Cell Genesys, Inc. (the "Current Stockholder") without registration under
the Securities Act of 1933, as amended (the "Act"), and the securities laws of
certain states, in reliance on the exemptions contained in Section 4(2) of the
Act and on Regulation D promulgated thereunder and in reliance on similar
exemptions under applicable state laws. The Corporation and the Current
Stockholder must determine that a potential investor meets certain suitability
requirements before offering or selling Securities to such investor. The purpose
of this Questionnaire is to assure the Corporation and the Current Stockholder
that each investor will meet the applicable suitability requirements. The
information supplied by you will be used in determining whether you meet such
criteria, and reliance upon the private offering exemption from registration is
based in part on the information herein supplied.

      This Questionnaire does not constitute an offer to sell or a solicitation
of an offer to buy any security. Your answers will be kept strictly
confidential. However, by signing this Questionnaire you will be authorizing the
Corporation and the Current Stockholder to provide a completed copy of this
Questionnaire to such parties as the Corporation or the Current Stockholder
deems appropriate in order to ensure that the offer and sale of the Securities
will not result in a violation of the Act or the securities laws of any state
and that you otherwise satisfy the suitability standards applicable to
purchasers of the Securities. All potential investors must answer all applicable
questions and complete, date and sign this Questionnaire. Please print or type
your responses and attach additional sheets of paper if necessary to complete
your answers to any item.

A. BACKGROUND INFORMATION

Name:
     ---------------------------------------------------------------------------

Business Address:
                 ---------------------------------------------------------------
                               (Number and Street)

--------------------------------------------------------------------------------
(City)                            (State)                             (Zip Code)

Telephone Number: (___)
                        --------------------------------------------------------

Residence Address:
                  --------------------------------------------------------------
                               (Number and Street)

--------------------------------------------------------------------------------
(City)                            (State)                             (Zip Code)


                                      -18-
<PAGE>

Telephone Number: (___)
                        --------------------------------------------------------

If an individual:
  Age:              Citizenship:                    Where registered to vote:
      ---------                 ------------                                 ---

If a corporation, partnership, limited liability company, trust or other entity:
   Type of entity:
                     -----------------------------------------------------------
  State of formation:                                      Date of formation:
                     -----------------------                                 ---

Social Security or Taxpayer Identification No.
                                              ----------------------------------

Send all correspondence to (check one): ____ Residence Address
                                        ____ Business Address

B. STATUS AS ACCREDITED INVESTOR

      The undersigned is an institutional "accredited investor" as such term is
defined in Regulation D under the Act, as at the time of the sale of the
Securities the undersigned falls within one or more of the following categories
(Please initial one or more, as applicable):

      ____ (1) a bank as defined in Section 3(a)(2) of the Act, or a savings and
loan association or other institution as defined in Section 3(a)(5)(A) of the
Act whether acting in its individual or fiduciary capacity; a broker or dealer
registered pursuant to Section 15 of the Securities Exchange Act of 1934; an
insurance company as defined in Section 2(13) of the Act; an investment company
registered under the Investment Corporation Act of 1940 or a business
development company as defined in Section 2(a)(48) of that Act; a Small Business
Investment Corporation licensed by the U.S. Small Business Administration under
Section 301(c) or (d) of the Small Business Investment Act of 1958; a plan
established and maintained by a state, its political subdivisions, or any agency
or instrumentality of a state or its political subdivisions for the benefit of
its employees, if such plan has total assets in excess of $5,000,000; an
employee benefit plan within the meaning of the Employee Retirement Income
Security Act of 1974 if the investment decision is made by a plan fiduciary, as
defined in Section 3(21) of such Act, which is either a bank, savings and loan
association, insurance company, or registered investment adviser, or if the
employee benefit plan has total assets in excess of $5,000,000 or, if a
self-directed plan, with the investment decisions made solely by persons that
are accredited investors;

      ____  (2)    a private business development company as defined in
Section 202(a)(22) of the Investment Adviser Act of 1940;

      ____ (3) an organization described in Section 501(c)(3) of the Internal
Revenue Code of 1986, as amended, corporation, Massachusetts or similar business
trust, or partnership, not formed for the specific purpose of acquiring the
Securities offered, with total assets in excess of $5,000,000;

      ____ (4) a trust, with total assets in excess of $5,000,000, not formed
for the specific purpose of acquiring the Securities offered, whose purchase is
directed by a sophisticated person as described in Rule 506(b)(2)(ii) of
Regulation D; and

      ____ (5) an entity in which all of the equity owners are accredited
investors (as defined above).

C. REPRESENTATIONS

      The undersigned hereby represents and warrants to the Corporation and the
Current Stockholder as follows:

1.    Any purchase of the Securities would be solely for the account of the
      undersigned and not for the account of any other person or with a view to
      any resale, fractionalization, division, or distribution thereof.


                                      -19-
<PAGE>

2.    The information contained herein is complete and accurate and may be
      relied upon by the Corporation and the Current Stockholder, and the
      undersigned will notify the Corporation and the Current Stockholder
      immediately of any material change in any of such information occurring
      prior to the closing, if any, with respect to the purchase of Securities
      by the undersigned or any co-purchaser.

3.    There are no suits, pending litigation, or claims against the undersigned
      that could materially affect the net worth of the undersigned as reported
      in this Questionnaire.

4.    The undersigned acknowledges that there may occasionally be times when the
      Corporation determines that it must suspend the use of the Prospectus
      forming a part of the Registration Statement (as such terms are defined in
      the Stock Purchase Agreement to which this Questionnaire is attached), as
      set forth in Section 7.2(c) of the Stock Purchase Agreement. The
      undersigned is aware that, in such event, the Securities will not be
      subject to ready liquidation, and that any Securities purchased by the
      undersigned would have to be held during such suspension. The overall
      commitment of the undersigned to investments which are not readily
      marketable is not excessive in view of the undersigned's net worth and
      financial circumstances, and any purchase of the Securities will not cause
      such commitment to become excessive. The undersigned is able to bear the
      economic risk of an investment in the Securities.

5.    The undersigned has carefully considered the potential risks relating to
      the Corporation and a purchase of the Securities, and fully understands
      that the Securities are speculative investments which involve a high
      degree of risk of loss of the undersigned's entire investment. Among
      others, the undersigned has carefully considered each of the risks
      identified under the caption "Additional Factors That Might Affect Future
      Results" in the report dated June 30, 2000 filed by the Corporation on
      Form 10-Q with the U.S. Securities and Exchange Commission.

            IN WITNESS WHEREOF, the undersigned has executed this Questionnaire
      this _____ day of October, 2000, and declares under oath that it is
      truthful and correct.


                                  Print Name


                                  By:
                                      -----------------------------------
                                        Signature

                                  Title:
                                         --------------------------------
                                        (required for any purchaser that is a
                                        corporation, partnership, trust or other
                                        entity)


                                      -20-
<PAGE>

                              [Company Letterhead]

                                 _________, 2000

      Re: Abgenix, Inc.; Registration Statement

Dear Selling Shareholder:

      Enclosed please find five (5) copies of a prospectus dated ______________,
____ (the "Prospectus") for your use in reselling your shares of common stock,
$0.0001 par value (the "Shares"), of Abgenix, Inc. (the "Company"), under the
Company's Registration Statement (Registration No. 333- ) (the "Registration
Statement"), which has been declared effective by the Securities and Exchange
Commission. As a selling shareholder under the Registration Statement, you have
an obligation to deliver a copy of the Prospectus to each purchaser of your
Shares, either directly or through the broker-dealer who executes the sale of
your Shares.

      The Company is obligated to notify you in the event that it suspends
trading under the Registration Statement in accordance with the terms of the
Stock Purchase Agreement between the Company, Cell Genesys, Inc. and you. During
the period that the Registration Statement remains effective and trading
thereunder has not been suspended, you will be permitted to sell your Shares
which are included in the Prospectus under the Registration Statement. Upon a
sale of any Shares under the Registration Statement, you or your broker will be
required to deliver to the Transfer Agent, ChaseMellon Shareholder Services,
L.L.C. (1) your restricted stock certificate(s) representing the Shares, (2)
instructions for transfer of the Shares sold, and (3) a representation letter
from your broker, or from you if you are selling in a privately negotiated
transaction, or from such other appropriate party, in the form of Exhibit A
attached hereto (the "Representation Letter"). The Representation Letter
confirms that the Shares have been sold pursuant to the Registration Statement
and in a manner described under the caption "Plan of Distribution" in the
Prospectus and that such sale was made in accordance with all applicable
securities laws, including the prospectus delivery requirements.

      Please note that you are under no obligation to sell your Shares during
the registration period. However, if you do decide to sell, you must comply with
the requirements described in this letter or otherwise applicable to such sale.
Your failure to do so may result in liability under the Securities Act of 1933,
as amended, and the Securities Exchange Act of 1934, as amended. Please remember
that all sales of your Shares must be carried out in the manner set forth under
the caption "Plan of Distribution" in the Prospectus if you sell under the
Registration Statement. The Company may require an opinion of counsel reasonably
satisfactory to the Company if you choose another method of sale. You should
consult with your own legal advisor(s) on an ongoing basis to ensure your
compliance with the relevant securities laws and regulations.

      In order to maintain the accuracy of the Prospectus, you must notify the
undersigned upon the sale, gift, or other transfer of any Shares by you,
including the number of Shares being transferred, and in the event of any other
change in the information regarding you which is contained in the Prospectus.
For example, you must notify the undersigned if you enter into any arrangement
with a broker-dealer for the sale of shares through a block trade, special
offering, exchange distribution or secondary distribution or a purchase by a
broker-dealer. Depending on the circumstances, such transactions may require the
filing of a supplement to the prospectus in order to update the information set
forth under the caption "Plan of Distribution" in the Prospectus.


                                      -21-
<PAGE>

      Should you need any additional copies of the Prospectus, or if you have
any questions concerning the foregoing, please write to me at Abgenix, Inc.,
7601 Dumbarton Circle, Fremont, CA 94555. Thank you.

                                                Sincerely,

                                                Chief Financial Officer


                                      -22-
<PAGE>

                                                                       Exhibit A

                         CERTIFICATE OF SUBSEQUENT SALE

ChaseMellon Shareholder Services, L.L.C.
235 Montgomery Street, 23rd Floor
San Francisco, CA  94101
Tel: (415) 743-1444
Attention: Asa Drew

            RE:   Sale of Shares of Common Stock of Abgenix, Inc. (the
                  "Company") pursuant to the Company's Prospectus dated
                  _____________, ____ (the "Prospectus")

Dear Sir/Madam:

      The undersigned hereby certifies, in connection with the sale of shares of
Common Stock of the Company included in the table of Selling Shareholders in the
Prospectus, that the undersigned has sold the shares pursuant to the Prospectus
and in a manner described under the caption "Plan of Distribution" in the
Prospectus and that such sale complies with all securities laws applicable to
the undersigned, including, without limitation, the Prospectus delivery
requirements of the Securities Act of 1933, as amended.

Selling Shareholder (the beneficial owner):

Record Holder (e.g., if held in name of nominee):
                                                  ------------------------------

Restricted Stock Certificate No.(s):
                                     -------------------------------------------

Number of Shares Sold:
                       ---------------------------------------------------------

Date of Sale:
              ------------------------------------------------------------------

      In the event that you receive a stock certificate(s) representing more
shares of Common Stock than have been sold by the undersigned, then you should
return to the undersigned a newly issued certificate for such excess shares in
the name of the Record Holder and BEARING A RESTRICTIVE LEGEND. Further, you
should place a stop transfer on your records with regard to such certificate.

                                                Very truly yours,

Dated:                                          By:
       -----------------------------                ----------------------------

                                                Print Name:
                                                            --------------------

                                                Title:
                                                       -------------------------

cc: Abgenix, Inc.
    7601 Dumbarton Circle
    Fremont, CA 94555
    Attn: Chief Financial Officer


                                      -23-