SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549



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                                    FORM 8-A

                FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                     PURSUANT TO SECTION 12(b) OR (g) OF THE
                         SECURITIES EXCHANGE ACT OF 1934



                                  ABGENIX, INC.
                      ------------------------------------
             (Exact name of Registrant as specified in its charter)


          DELAWARE                                         94-3248826
- ---------------------------------------        ---------------------------------
(State of incorporation or organization)       (IRS Employer Identification No.)

                              7601 Dumbarton Circle
                            Fremont, California 94555
               (Address of principal executive offices) (Zip Code)

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

Securities to be registered pursuant to Section 12(b) of the Act:

         Title of each class                      Name of each exchange on which
         to be so registered                      each class is to be registered
         -------------------                      ------------------------------

                None                                           None

Securities to be registered pursuant to Section 12(g) of the Act:

                         Preferred Share Purchase Rights
                         -------------------------------
                                (Title of Class)




Item 1.           DESCRIPTION OF SECURITIES TO BE REGISTERED.

          On June 2, 1999, the Board of Directors of Abgenix, Inc. (the
"Company") declared a dividend of one right (a "Right") to purchase one
one-thousandth share of the Company's Series A Participating Preferred Stock
("Series A Preferred") for each outstanding share of Common Stock, $0.0001 par
value ("Common Shares"), of the Company, and on June 14, 1999, the Company and
ChaseMellon Shareholder Services, L.L.C., a New Jersey limited liability
company, as Rights Agent (the "Rights Agent") entered into a Preferred Shares
Rights Agreement (the "Rights Agreement"). The dividend is payable on June 14,
1999 (the "Record Date"), to shareholders of record as of the close of business
on that date. Each Right entitles the registered holder to purchase from the
Company one one-thousandth of a share of Series A Preferred at an exercise price
of $120.00 (the "Purchase Price"), subject to adjust ment.

          The following summary of the principal terms of the Rights Agreement
is a general description only and is subject to the detailed terms and
conditions of the Rights Agreement. A copy of the Rights Agreement is attached
as EXHIBIT 1 to this Registration Statement and is incorporated herein by
reference.

RIGHTS EVIDENCED BY COMMON SHARE CERTIFICATES

          The Rights will not be exercisable until the Distribution Date
(defined below). Certificates for the Rights ("Rights Certificates") will not be
sent to shareholders and the Rights will attach to and trade only together with
the Common Shares. Accordingly, Common Share certificates outstanding on the
Record Date will evidence the Rights related thereto, and Common Share
certificates issued after the Record Date will contain a notation incorporating
the Rights Agreement by reference. Until the Distribution Date (or earlier
redemption or expiration of the Rights), the surrender or transfer of any
certificates for Common Shares, outstanding as of the Record Date, even without
notation or a copy of the Summary of Rights being attached thereto, also will
constitute the transfer of the Rights associated with the Common Shares
represented by such certificate.

DISTRIBUTION DATE

          The Rights will separate from the Common Shares, Rights Certificates
will be issued and the Rights will become exercisable upon the earlier of: (i)
10 days following a public announcement that a person or group of affiliated or
associated persons (an "Acquiring Person") has acquired, or obtained the right
to acquire, beneficial ownership of 15% or more of the outstanding Common
Shares, or (ii) 10 business days (or such later date as may be determined by
action of the Company's Board of Directors) following the commencement of, or
announcement of a tender offer or exchange offer the consummation of which would
result in the beneficial ownership by a person or group of 15% or more of the
outstanding Common Shares; PROVIDED HOWEVER, that Cell Genesys, Inc. ("Cell
Genesys") shall not be deemed an "Acquiring Person" and shall not trigger any
condition described above until such time as Cell Genesys shall beneficially own
more than 25% of the outstanding Common Shares or announces


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a tender offer to acquire more than 25% of the outstanding Common Shares or
until such time as Cell Genesys shall be required to file a report of beneficial
ownership on Schedule 13D with the Securities and Exchange Commission with
respect to its holdings of Common Shares (collectively, the "Limitations"). The
earlier of such dates is referred to as the "Distribution Date."

ISSUANCE OF RIGHTS CERTIFICATES; EXPIRATION OF RIGHTS

          As soon as practicable following the Distribution Date, separate
Rights Certificates will be mailed to holders of record of the Common Shares as
of the close of business on the Distribution Date and such separate Rights
Certificates alone will evidence the Rights from and after the Distribution
Date. All Common Shares issued, after the Distribution Date will be issued with
Rights. The Rights will expire on the earliest of (i) June 2, 2009 (the "Final
Expiration Date"), or (ii) redemption or exchange of the Rights as described
below.

INITIAL EXERCISE OF THE RIGHTS

          Following the Distribution Date, and until one of the further events
described below, holders of the Rights will be entitled to receive, upon
exercise and the payment of the Purchase Price, one one-thousandth share of the
Series A Preferred. In the event that the Company does not have sufficient
Series A Preferred available for all Rights to be exercised, or the Board
decides that such action is necessary and not contrary to the interests of
Rights holders, the Company may instead substitute cash, assets or other
securities for the Series A Preferred for which the Rights would have been
exercisable under this provision or as described below.

RIGHT TO BUY COMPANY COMMON SHARES

          Unless the Rights are earlier redeemed, in the event that an Acquiring
Person becomes the benefi cial owner of 15% or more of the Company's Common
Shares then outstanding, then each holder of a Right which has not theretofore
been exercised (other than Rights beneficially owned by the Acquiring Person,
which will thereafter be void) will thereafter have the right to receive, upon
exercise, Common Shares having a value equal to two times the Purchase Price.
Rights are not exercisable following the occurrence of an event as described
above until such time as the Rights are no longer redeemable by the Company as
set forth below.

RIGHT TO BUY ACQUIRING COMPANY STOCK

          Similarly, unless the Rights are earlier redeemed, in the event that,
after an Acquiring Person becomes the beneficial owner of 15% or more of the
Company's Common Shares then outstanding, (i) the Company is acquired in a
merger or other business combination transaction, or (ii) 50% or more of the
Company's consolidated assets or earning power are sold (other than in
transactions in the ordinary course of business), proper provision must be made
so that each holder of a Right which has not thereto fore been exercised (other
than Rights beneficially owned by the Acquiring Person, which will thereafter


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be void) will thereafter have the right to receive, upon exercise, shares of
common stock of the acquiring company having a value equal to two times the
Purchase Price.

EXCHANGE PROVISION

          At any time after the acquisition by an Acquiring Person of 15% or
more of the Company's outstanding Common Shares and prior to the acquisition by
such Acquiring Person of 50% or more of the Company's outstanding Common Shares,
the Board of Directors of the Company may exchange the Rights (other than Rights
owned by the Acquiring Person), in whole or in part, at an exchange ratio of one
Common Share per Right.

REDEMPTION

         At any time on or prior to the close of business on the earlier of (i)
the Distribution Date, or (ii) the Final Expiration Date, the Company may redeem
the Rights in whole, but not in part, at a price of $0.01 per Right.

ADJUSTMENTS TO PREVENT DILUTION

          The Purchase Price payable, the number of Rights, and the number of
Series A Preferred or Common Shares or other securities or property issuable
upon exercise of the Rights are subject to adjustment from time to time in
connection with the dilutive issuances by the Company as set forth in the Rights
Agreement. With certain exceptions, no adjustment in the Purchase Price will be
required until cumulative adjustments require an adjustment of at least 1% in
such Purchase Price.

CASH PAID INSTEAD OF ISSUING FRACTIONAL SHARES

          No fractional portion less than integral multiples of one Common Share
will be issued upon exercise of a Right and, in lieu thereof, an adjustment in
cash will be made based on the market price of the Common Shares on the last
trading date prior to the date of exercise.

NO SHAREHOLDERS' RIGHTS PRIOR TO EXERCISE

          Until a Right is exercised, the holder thereof, as such, will have no
rights as a shareholder of the Company (other than any rights resulting from
such holder's ownership of Common Shares), including, without limitation, the
right to vote or to receive dividends.

AMENDMENT OF RIGHTS AGREEMENT

          The terms of the Rights and the Rights Agreement may be amended in any
respect without the consent of the Rights holders on or prior to the
Distribution Date; thereafter, the terms of the Rights and the Rights Agreement
may be amended without the consent of the Rights holders in order to cure any


                                       -4-


ambiguities or to make changes which do not adversely affect the interests of
Rights holders (other than the Acquiring Person).

RIGHTS AND PREFERENCES OF THE SERIES A PREFERRED

          Each one one thousandth of a share of Series A Preferred has rights
and preferences substantially equivalent to those of one Common Share.

CERTAIN ANTI-TAKEOVER EFFECTS

          The Rights approved by the Board are designed to protect and maximize
the value of the outstanding equity interests in the Company in the event of an
unsolicited attempt by an acquiror to take over the Company in a manner or on
terms not approved by the Board of Directors. Takeover attempts frequently
include coercive tactics to deprive the Company's Board of Directors and its
shareholders of any real opportunity to determine the destiny of the Company.
The Rights have been declared by the Board in order to deter such tactics,
including a gradual accumulation of shares in the open market of 15% or greater
position (or, with respect to Cell Genesys, its failure to meet the Limitations)
to be followed by a merger or a partial or two-tier tender offer that does not
treat all shareholders equally. These tactics unfairly pressure shareholders,
squeeze them out of their investment without giving them any real choice and
deprive them of the full value of their shares.

          The Rights are not intended to prevent a takeover of the Company and
will not do so. Subject to the restrictions described above, the Rights may be
redeemed by the Company at $0.01 per Right at any time prior to the Distribution
Date. Accordingly, the Rights should not interfere with any merger or business
combination approved by the Board of Directors.

          Issuance of the Rights does not in any way weaken the financial
strength of the Company or interfere with its business plans. The issuance of
the Rights themselves has no dilutive effect, will not affect reported earnings
per share, should not be taxable to the Company or to its shareholders, and will
not change the way in which the Company's shares are presently traded. The
Company's Board of Directors believes that the Rights represent a sound and
reasonable means of addressing the complex issues of corporate policy created by
the current takeover environment.

          However, the Rights may have the effect of rendering more difficult or
discouraging an acquisition of the Company deemed undesirable by the Board of
Directors. The Rights may cause substantial dilution to a person or group that
attempts to acquire the Company on terms or in a manner not approved by the
Company's Board of Directors, except pursuant to an offer conditioned upon the
negation, purchase or redemption of the Rights.


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Item 2.           EXHIBITS.

                  1.       Preferred Shares Rights Agreement, dated as of June
                           14, 1999, between Abgenix, Inc. and ChaseMellon
                           Shareholder Services, L.L.C., including the
                           Certificate of Determination, the form of Rights
                           Certificate and the Summary of Rights attached
                           thereto as EXHIBITS A, B and C, respectively.


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                                    SIGNATURE

          Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the Registrant has duly caused this Registration Statement to be
signed on its behalf by the undersigned, thereto duly authorized.


                                                              ABGENIX, INC.

Date:  June 14, 1999

                                  By: /S/ KURT W. LEUTZINGER
                                      ------------------------------------------
                                                 Kurt W. Leutzinger
                                      Vice President and Chief Financial Officer







                                  EXHIBIT INDEX

     EXHIBIT
       NO.                                 EXHIBIT

       1.         Preferred Shares Rights Agreement, dated as of June 14, 1999,
                  between Abgenix, Inc. and ChaseMellon Shareholder Services,
                  L.L.C., including the Certificate of Determination, the form
                  of Rights Certificate and the Summary of Rights attached
                  thereto as EXHIBITS A, B and C, respectively.




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