SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C. 20549


                                      ----------


                                  AMENDMENT NO. 1

                                         TO

                                      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 "Prior 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 adjustment.  On
November 19, 1999, the Company and the Rights Agent entered into the Amended
Preferred Shares Rights Agreement (the "Amended Rights Agreement") which
supersedes and replaces the Prior Rights Agreement as originally exectued.  The
Amended Rights Agreement is substantially the same as the Prior Rights Agreement
as originally executed, except that all references to Cell Genesys, Inc. are
amended to include Cells Genesys, Inc., its affilates, successors or assigns.

     The following summary of the principal terms of the Amended Rights
Agreement is a general description only and is subject to the detailed terms and
conditions of the Amended Rights Agreement.  A copy of the Amended 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 Amended
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

                                     -3-


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., its affliates, successors
or assigns (collectively, "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 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 beneficial 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

                                     -4-


     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 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, 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.

                                      -5-


AMENDMENT OF RIGHTS AGREEMENT

     The terms of the Rights and the Amended 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 Amended Rights
Agreement may be amended without the consent of the Rights holders in order to
cure any 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

                                      -6-


not approved by the Company's Board of Directors, except pursuant to an offer
conditioned upon the negation, purchase or redemption of the Rights.



Item 2.   EXHIBITS.

          1.   Amended Preferred Shares Rights Agreement, dated as of November
               19, 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.




                                      -7-



                                      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: November 30, 1999
                                   By: /s/ Kurt W. Leutzinger
                                       ----------------------
                                       Kurt W. Leutzinger
                                       Vice President and Chief Financial
                                         Officer







                                   EXHIBIT INDEX


 Exhibit No.                          Exhibit
 -----------                          -------
      1.      Amended Preferred Shares Rights Agreement, dated as of November
              19, 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.



                                      -9-