SECURITIES AND EXCHANGE
COMMISSIONWashington, D.C. 20549 FORM 10-K/A(Amendment No. 1) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D)
OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31, 2000
Commission file number 000-24207  ABGENIX, INC.(Exact Name of Registrant as Specified in Its Charter)  Delaware
  94-3248826(State or Other
  Jurisdiction of Incorporation or
  Organization)
  (IRS Employer
  Identification No.)6701
  Kaiser Drive, Fremont, California
  94555(Address of Principal
  Executive Offices)
  (Zip
  Code)
 (510) 608-6500(Registrants Telephone Number, Including Area Code) Securities registered pursuant to Section 12(b) of the
Act:  None Securities registered pursuant
to Section 12(g) of the Act: Common
Stock, $0.0001 par value
(Title of Class) Preferred
Share Purchase Rights
(Title of Class) Indicate
by check mark whether the registrant: (1) has filed all reports required to be
filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the
preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.  YesxNoo Indicate
by check mark if disclosure of delinquent filers pursuant to Item 405 of
Regulation S-K is not contained herein, and will not be contained, to the best
of the registrants knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to
this  Form 10–K.x The
aggregate market value of the voting stock held by non-affiliates of the
Registrant as of April 30, 2001 was $2,508,659,835. The number of shares of
Common Stock, $0.0001 par value, outstanding on April 30, 2001, was 85,936,370. DOCUMENTS INCORPORATED BY
REFERENCE None.


EXPLANATORY NOTE This
Amendment No. 1 to the Annual Report on Form 10-K for the fiscal year ended
December 31, 2000 is being filed by Abgenix, Inc., a Delaware corporation (the
Company or Abgenix), in order to provide the information required by Items
10, 11, 12 and 13 of Part III of Form 10-K which the Company had intended to
incorporate by reference to its definitive proxy statement. PART III Item 10.  Directors of
the Registrant Name
  Age
  Position(s)R. Scott Greer
  42
  Chairman and Chief Executive OfficerM. Kathleen
  Behrens, Ph.D.(1)
  48
  DirectorRaju S. Kucherlapati, Ph.D.
  58
  DirectorMark B.
  Logan(1)(2)
  62
  DirectorJoseph E.
  Maroun
  71
  DirectorStephen A.
  Sherwin, M.D.(1)(2)
  52
  Director  (1) Member of the Boards Audit Committee.
(2) Member of the Boards Compensation Committee. R. Scott Greer, has served as our Chairman of the Board since
May 2000, and as our Chief Executive Officer and director since
June 1996. From June 1996 until December 2000, he served as our
President.  He also serves as a director
of CV Therapeutics, Inc.  From
July 1994 to July 1996, Mr. Greer was Senior Vice President of
Corporate Development at Cell Genesys, Inc. 
From April 1991 to July 1994, Mr. Greer was Vice
President of Corporate Development and from April 1991 to
September 1993 was Chief Financial Officer of Cell Genesys.  From 1986 to 1991, Mr. Greer held
various positions at Genetics Institute, Inc., a biotechnology company,
including Director, Corporate Development. 
Mr. Greer received a BA degree in Economics from Whitman College
and an MBA degree from Harvard University. 
Mr. Greer is also a certified public accountant. M. Kathleen Behrens, Ph.D.,has served as one of our directors since
December 1997.  Dr. Behrens
joined Robertson Stephens Investment Management Co. in 1983 and became a
general partner in 1986 and a managing director in 1993.  In 1988, Dr. Behrens joined the venture
capital group of Robertson Stephens Investment Management Co. and has helped in
the founding of two biotechnology companies: Protein Design
Laboratories, Inc. and COR Therapeutics, Inc.  Dr. Behrens is the former president,
chair and director of the National Venture Capital Association.  Dr. Behrens received a Ph.D. degree in
Microbiology from the University of California, Davis, where she performed
genetic research for six years. Raju S. Kucherlapati, Ph.D., has served as one of our directors since
June 1996.  Dr. Kucherlapati
was a founder of Cell Genesys and served as a director of Cell Genesys from
1988 to 1999.  Since July 1989, he
has been the Saul and Lola Kramer Professor and the Chairman of the Department
of Molecular Genetics at the Albert Einstein College of Medicine.  Dr. Kucherlapati also serves as a
director of Valentis Corp. and Millennium Pharmaceuticals, Inc.  Dr. Kucherlapati received a BS degree
in Biology from Andhra University in India and a Ph.D. degree in Genetics from
the University of Illinois, Urbana. Mark B. Logan, has served as one of our directors since
August 1997.  Mr. Logan has
served as Chairman of the Board, of VISX, Incorporated, a medical device
company, since November 1994.  He
also served as Chief Executive Officer of VISX, Incorporated from November 1994
until February 2001 and as President from November 1994 until February
1999.  From January 1992 to
October 1994, he was Chairman of the Board and Chief Executive Officer of
INSMED Pharmaceuticals, Inc., a pharmaceutical company.  Previously, Mr. Logan held several
senior management positions at Bausch & Lomb, Inc., a medical
products company, including Senior Vice President, Healthcare and Consumer
Group, and also served as a member of its board of directors.  Mr. Logan currently serves as a
director of Somnus Medical Technologies, Inc.,  Vivus, Inc. and Align Technology, Inc.  Mr. Logan received a BA degree from Hiram College and a PMD
degree from Harvard Business School. Joseph E. Maroun,has served as one of our directors since
July 1996 and served as a director of Cell Genesys from June 1995 to
June 2000.  Mr. Maroun spent
30 years with Bristol-Myers Squibb, a pharmaceuticals company, serving
until his retirement in 1990, at which time he was President of the
International Group, Senior Vice President of the corporation, and a member of
its Policy Committee.  He also headed
the U.S.-Japan Pharmaceutical Advisory Group. 
Mr. Maroun received a BA degree from the University of
Witwaterrand, Johannesburg.  Stephen A. Sherwin, M.D.,has served as one of our directors since
June 1996, and served as Chairman of the Board from June 1996 to
May 2000.  Since March 1990,
Dr. Sherwin has served as President, Chief Executive Officer and a
director of Cell Genesys.  Since March 1994,
he has served as Chairman of the Board of Cell Genesys.  From 1983 to 1990, Dr. Sherwin held
various positions at Genentech, Inc., a biotechnology company, most
recently as Vice President, Clinical Research. 
Dr. Sherwin currently serves as a Director of the California
Healthcare Institute,  Neurocrine
Biosciences, Inc. and Rigel Pharmaceuticals, Inc.  Dr. Sherwin received a BA degree in
Biology from Yale University and an M.D. degree from Harvard Medical School. Section 16(a) Beneficial
Ownership Reporting Compliance Section
16(a) of the Exchange Act requires the Companys directors and executive officers,
and persons who own more than ten percent of a registered class of the
Companys equity securities, to file initial reports of ownership and reports
of changes in ownership of common stock and other equity securities of the
Company with the Securities and Exchange Commission.  Officers, directors and greater than ten percent beneficial
owners are required by Securities and Exchange Commission regulation to furnish
the Company with copies of all Section 16(a) forms they file. To
the Companys knowledge, based solely on a review of the copies of such reports
furnished to the Company and written representations that no other reports were
required, during the fiscal year ended December 31, 2000, the Companys
officers, directors and greater than ten percent beneficial owners complied
with all applicable Section 16(a) filing requirements. Item 11. Executive Compensation COMPENSATION OF EXECUTIVE
OFFICERS Summary of Compensation The
following table shows for the fiscal years ended 1998, 1999 and 2000, compensation
awarded or paid to, or earned by, the Companys Chief Executive Officer and its
four other most highly compensated executive officers at December 31, 2000,
each of whose aggregate compensation during the last fiscal year exceeded
$100,000 (the Named Executive Officers): Summary
Compensation Table Long-Term CompensationName and Principal Position
  Fiscal
  Year
  Annual Compensation
  Securities
  Underlying
  Options (#)
  All Other
  Compensation
  ($)Salary ($)
  Bonus ($)R. Scott Greer
  2000
  $366,000
  $250,000
  405,000
  Chief Executive Officer
  1999
  283,147
  200,000
  540,000
  1998
  267,120
  
  160,000
  Raymond M. Withy,
  Ph.D.
  2000
  $241,500
  $90,563
  153,000
  President
  1999
  184,547
  100,000
  153,000
  1998
  165,350
  
  40,000
  C. Geoffrey Davis,
  Ph.D.
  2000
  $237,110
  $88,916
  153,000
  $1,011(1)Chief Scientific Officer
  1999
  184,546
  100,000
  153,000
  1,482(1)1998
  165,350
  
  40,000
  Kurt W. Leutzinger
  2000
  $240,750
  $90,281
  153,000
  $5,630(2)Chief Financial Officer
  1999
  187,922
  100,000
  153,000
  4,940(2)1998
  179,830
  
  51,000
  19,623(3)Gisela M. Schwab,
  M.D.(4)
  2000
  $220,000
  $144,788
  
  $121,932(4)Vice President, Clinical
  Development
  1999
  36,667
  100,000
  400,000
    (1)         Consists
of imputed interest income on a loan from us to Dr. Davis.(2)         Consists
of imputed interest income on a loan from us to Mr. Leutzinger.
(3)         Consists
of $18,714 for reimbursement of relocation expenses and $909 for imputed
interest income on a loan from us to Mr. Leutzinger.
(4)         Dr.
Schwab has been our Vice President, Clinical Development since
November 1999.  Her 1999 annualized
salary was $220,000. Other compensation consists of $117,465 for reimbursement
of relocation expenses and $4,467 of imputed interest. Option Grants in Last Fiscal
Year The
following table provides information relating to stock options awarded to each
of the Named Executive Officers during the year ended December 31,
2000.  All these options were awarded
under our 1996 Incentive Stock Plan. Option Grants in Last Fiscal Year

Name
  Individual Grants
  Potential Realizable Value at Assumed Annual Rates of Stock
  Price Appreciation For Option Term(4)Number of
  Securities
  Underlying
  Options
  Granted(1)
  Percent of
  Total Options
  Granted to
  Employees in
  Fiscal Year(2)
  Exercise or
  Base Price
  ($/Share)(3)
  Expiration
  Date5%
  10%R. Scott Greer
  405,000
  7.3%
  $31.8125
  2/02/10
  $8,102,718
  $20,533,877Raymond M. Withy, Ph.D.
  153,000
  2.7%
  31.8125
  2/02/10
  3,061,027
  7,757,243C. Geoffrey Davis, Ph.D.
  153,000
  2.7%
  31.8125
  2/02/10
  3,061,027
  7,757,243Kurt W. Leutzinger
  153,000
  2.7%
  31.8125
  2/02/10
  3,061,027
  7,757,243Gisela M. Schwab, M.D.
  
  
  
  
  
  (1)         All of
the options granted became exercisable as to 1/48th of the option shares on the
date of grant and an additional 1/48th of the option shares become exercisable
on the first day of each calendar month thereafter, with full vesting occurring
four years after the date of grant.  In
each case, vesting is subject to the optionees continued relationship with
us.  These options expire ten years from
the date of grant, or earlier upon termination of employment.

(2)         Based
on an aggregate of 5,585,930 options granted by us in the year ended
December 31, 2000 to our employees, non-employee directors of and
consultants, including the Named Executive Officers.

(3)         Options
were granted at an exercise price equal to the fair market value of our common
stock, as determined by our board of directors on the date of grant.

(4)         The 5%
and 10% assumed annual rates of compounded stock price appreciation are
mandated by rules of the Securities and Exchange Commission.  We cannot provide any assurance to any
executive officer or any other holder of our securities that the actual stock
price appreciation over the option term will be at the assumed 5% and 10%
levels or at any other defined level. 
Unless the market price of our common stock appreciates over the option
term, no value will be realized from the option grants made to the executive
officers.  The potential realizable
value is calculated by assuming that the fair value of our common stock on the
date of grant appreciates at the indicated rate for the entire term of the
option and that the option is exercised at the exercise price and sold on the
last day of its term at the appreciated price. 
The potential realizable value computation is net of the applicable
exercise price, but does not take into account applicable federal or state
income tax consequences and other expenses of option exercises or sales of
appreciated stock.

Aggregated Option Exercises in
Last Fiscal Year and Fiscal Year-End Option Values

The
following table sets forth for each of the Named Executive Officers the number
of shares of our common stock acquired and the dollar value realized upon
exercise of options during the year ended December 31, 2000 and the number
and value of securities underlying unexercised options held at
December 31, 2000:

Aggregate
Option Exercises in Last Fiscal Yearand Fiscal Year-End Option Values

Name
  # SharesAcquired onExercise
  ValueRealized(1)
  Number of Securities
  Underlying UnexercisedOptions at Fiscal Year-End
  Value of UnexercisedIn-the-Money Optionsat Fiscal Year-End(2)Exercisable
  Unexercisable
  Exercisable
  UnexercisableR. Scott Greer
  575,000
  $27,377,920
  621,693
  661,577
  $33,351,309
  $28,010,568Raymond M.
  Withy, Ph.D.
  364,918
  15,029,485
  123,160
  218,258
  5,870,995
  8,818,411C. Geoffrey
  Davis, Ph.D.
  275,000
  12,645,250
  122,742
  218,258
  6,021,889
  8,818,411Kurt W.
  Leutzinger
  50,000
  2,976,250
  158,284
  268,716
  7,956,165
  11,764,644Gisela M.
  Schwab, M.D.
  15,000
  801,250
  93,333
  291,667
  4,602,484
  14,382,829(1)         Value
realized reflects the aggregate fair market value of our common stock
underlying the option on the date of exercise minus the aggregate exercise
price of the option.

(2)         Value
of unexercised in-the-money options are based on a value of $59.0625 per share,
the closing price of our common stock on December 31, 2000. Amounts
reflected are based on the value of $59.0625 per share, minus the per share
exercise price, multiplied by the number of shares underlying the option.

Change of Control Agreements

We
have entered into change of control severance agreements with Messrs. Greer,
Davis, Leutzinger and Withy, and Ms. Schwab. 
These agreements provide in pertinent part that if any of the following
events occur within 24 months following a change of control, then the Company,
or the company with which we merge, must pay the affected officer such
officers salary and bonus, at the rate in effect just prior to the change of
control, for one year or, in Mr. Greers case, two years:  (i) a termination of the officers
employment without good cause; (ii) a material reduction in the officers
salary or benefits or a substantial reduction of the officers perquisites,
such as office space, without such officers consent or good business reason;
(iii) a significant reduction in the officers duties, position or
responsibilities without such officers consent; or (iv) a relocation of the
officers employment by more than 35 miles without such officers consent.

These
agreements further provide for gross up payments to the officers in the event
that they are subject to the tax codes excise tax on so-called excess parachute
payments.  For purposes of these
agreements, a change in control includes (1) a person becoming the beneficial
owner of more than 50% of the total voting power represented by the Companys
securities; (2) a merger or consolidation in which Abgenix stockholders
immediately before the transaction own less than 50% of the total voting power
represented by the Companys securities; (3) liquidation or sale of all or
substantially all of the Companys assets; or (4) certain changes in the
composition of the Board such that the incumbent directors before the change
are less than a majority of the Board after the change.

The
Companys Board of Directors has approved a plan which provides that in the
event of a change in control of Abgenix, the options of each Abgenix employee
whose employment is terminated without cause within 24 months of the change in
control will become exercisable in full. 
For these purposes, a change in control includes: (1) a person becoming
the beneficial owner of 50% or more of our outstanding voting securities; (2)
certain changes in the composition of our Board of Directors occurring within a
two-year period; or (3) a merger or consolidation in which Abgenix stockholders
immediately before the transaction own less than a majority of the outstanding
voting securities of the surviving entity, or its parent, immediately after the
transaction.

Compensation Committee
Interlocks and Insider Participation

None
of the members of our Compensation Committee was, at any time since our formation,
an officer or employee of Abgenix.  None
of our executive officers serves as a member of the board of directors or
compensation committee of any entity that has one or more executive officers
serving as a member of our Board of Directors or Compensation Committee.

Report of the Compensation Committee of The Board of
Directors on Executive Compensation

The
Compensation Committee is responsible for making recommendations to the Board
of Directors concerning salaries and incentive compensation for employees of
and consultants to Abgenix.  The
Compensation Committee also has the authority and power to grant stock options
to our employees and consultants.

The
goal of our compensation policies is to align executive compensation with
business objectives, corporate performance, and to attract and retain
executives who contribute to the long-term success and value of Abgenix.  We endeavor to achieve our compensation
goals through the implementation of policies that are based on the following
principles:

          THE COMPANY PAYS COMPETITIVELY FOR EXPERIENCED, HIGHLY SKILLED
EXECUTIVES:

The
Company operates in a competitive and rapidly changing biopharmaceutical
industry.  Executive base compensation
is targeted to the median salary paid to comparable executives in companies of
similar size and location, and with comparable responsibilities.  The individual executives salary is
adjusted annually based on individual performance, corporate performance, and
the relative compensation of the individual compared to the comparable medians.          THE COMPANY REWARDS EXECUTIVES FOR
SUPERIOR PERFORMANCE:

The
Compensation Committee believes that a substantial portion of each executives
compensation should be in the form of bonuses. 
Executive bonuses are based on a combination of individual performance
and the attainment of corporate goals. 
Individual performance goals are based on specific objectives which must
be met in order for the Company to achieve its corporate goals.  In order to attract and retain executives
who are qualified to excel in the biopharmaceutical industry, the Company
awards higher bonuses based on performance in excess of the corporate goals.          THE COMPANY STRIVES TO ALIGN
LONG-TERM STOCKHOLDER AND EXECUTIVE INTERESTS:

In
order to align the long-term interests of executives with those of
stockholders, the Company grants all employees, and particularly executives,
options to purchase stock.  Options are
granted at the closing price of one share of the Companys common stock on the
date of grant and will provide value only when the price of the common stock
increases above the exercise price. 
Options are subject to vesting provisions designed to encourage
executives to remain employed by the Company. 
Additional options are granted from time to time based on individual
performance and the prior level of grants.Compensation of R. Scott Greer,
Chief Executive Officer and Chairman of the Board

Mr.
Greers salary and stock option grant for fiscal 2000 are consistent with the
criteria described above and with the Compensation Committees evaluation of
his overall leadership and management of Abgenix.  2000 was a year of significant accomplishments for us.  We made significant progress in advancing
our product pipeline, expanding our list of XenoMouse technology
collaborations, entering into product development partnerships, acquiring new,
complementary technologies through acquisitions, and building our financial
strength.  A Phase II trial of one product
candidate was completed, and Phase II trial of another was initiated.  Three product candidates are presently
undergoing clinical trials, in indications including psoriasis,
graft-versus-host disease, cancer and rheumatoid arthritis.  In addition, we completed two equity
offerings in 2000, raising approximately $717.1 million.  Mr. Greer has continued to provide strategic
direction to us and to build our organization. 
Mr. Greers compensation for 2000 is set forth in the Summary
Compensation Table appearing on page 4.

Compliance with Internal
Revenue Code Section 162(m)

Section
162(m) of the Internal Revenue Code
provides that compensation paid to a public companys chief executive officer
and its four other highest paid executive officers in tax years 1994 and
thereafter in excess of $1 million is not deductible unless such compensation
is paid only upon the achievement of objective performance goals where certain
procedural requirements have been satisfied. 
Alternatively, such compensation may be deferred until the executive
officer is no longer a covered person under Section 162(m).  Based on fiscal year 2000 compensation
levels, no such limits on the deductibility of compensation applied to any
officer of Abgenix.

Summary

The Compensation Committee believes
that our compensation policy as practiced to date by the Compensation Committee
and the Board has been successful in attracting and retaining qualified
employees and in tying compensation directly to corporate performance relative
to corporate goals.  Our compensation
policy will evolve over time as we attempt to achieve the many short-term goals
we face while maintaining our focus on building long-term stockholder value
through technological leadership and development and expansion of the market
for our products.

Respectfully
  submitted,/s/
  Stephen A. Sherwin, M.D./s/
  Mark B. LoganTHE FOREGOING COMPENSATION COMMITTEE
REPORT SHALL NOT BE DEEMED TO BE FILED WITH THE SECURITIES AND EXCHANGE
COMMISSION, NOR SHALL SUCH INFORMATION BE INCORPORATED BY REFERENCE INTO ANY
FUTURE FILING UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE SECURITIES
ACT), OR THE EXCHANGE ACT, EXCEPT TO THE EXTENT THE COMPANY SPECIFICALLY
INCORPORATES IT BY REFERENCE INTO SUCH FILING.

Compensation of Directors

Each
non-employee director of the Company receives a yearly retainer of $5,000 and a
per meeting fee of $1,000 (plus $500 for each committee meeting attended by
committee members or for special assignments of the Board of Directors).  The members of the Board of Directors are also
eligible for reimbursement for their expenses incurred in connection with
attendance at Board meetings in accordance with Company policy.

Each
non-employee director of the Company also receives stock option grants under
the 1998 Director Option Plan, as amended (the Directors Plan).  Only non-employee directors of the Company
are eligible to receive options under the Directors Plan.  Options granted under the Directors Plan do
not qualify as incentive stock options under the Internal Revenue Code.

Under
the Directors Plan, each new non-employee director receives a stock option
grant on the date such person first becomes a non-employee director, and each
non-employee director receives an annual stock option grant.  The size of these grants is determined on an
annual basis by resolution of the Board of Directors.  For fiscal year 2001, each annual grant will be an option to
purchase 7500 shares of our common stock. The annual grants are made on the
date of the Companys Annual Meeting of Stockholders to each non-employee
director who has served on the board for at least six months.  The annual and initial grants do not require
action by the Companys stockholders. 
No other options may be granted at any time under the Directors
Plan.  The exercise price of options
granted under the Directors Plan is 100% of the fair market value of our
common stock on the date of grant.

All
options granted on or after June 1999 are fully vested upon grant.  The term of options granted under the
Directors Plan is ten years.  In the
event of a merger of the Company with or into another corporation or a
consolidation, acquisition of assets or other change-in-control transaction
involving the Company, each option either will continue in effect, if the
Company is the surviving entity, or will be assumed or an equivalent option
will be substituted by the successor corporation, if the Company is not the
surviving entity.  If the successor
corporation does not assume an outstanding option or substitute it for an
equivalent option, then the option shall become fully vested and
exercisable.  In addition, following
such assumption or substitution, if the optionees status as a director is
terminated other than upon a voluntary resignation by the optionee, the option
shall become fully vested and exercisable.

During
the last fiscal year, the Company granted options covering 30,000 shares of our
common stock to each non-employee director of the Company, at an exercise price
per share of $48.0625, which was the fair market value of our common stock on
the date of grant based on the closing sales price reported on the Nasdaq
National Market.

COMPARISON
OF CUMULATIVE TOTAL RETURN ON INVESTMENT*

The stock price performance depicted in the following
graph is not necessarily indicative of future price performance. The
information contained in the stock performance graph shall not be deemed to be
"filed" with the Securities and Exchange Commission, nor shall such
information be incorporated by reference into any future filing under the
Securities Act or the Exchange Act, except to the extent the company
specifically incorporates it by reference into such filing.

The
following graph shows a comparison of total stockholder return for holders of
our common stock from July 2, 1998, the date our common stock first traded on
the Nasdaq National Market, through December 31, 2000 compared with the Nasdaq
Composite Index and the Pharmaceutical Index. This graph is presented pursuant
to the Securities and Exchange Commission rules. We believe that while total
stockholder return can be an important indicator of corporate performance, the
prices of biopharmaceutical stocks like that of Abgenix are subject to a number
of market-related factors other than company performance, such as competitive
announcements, drug discovery and commercialization, mergers and acquisitions
in the industry, the general state of the economy, and the performance of other
biopharmaceutical stocks.







*  
$100 invested on 7/2/98 in stock or on 6/30/98 in the indicesincluding
reinvestment of dividends. Fiscal year ending December 31.



Item 12. Security Ownership of Certain Beneficial Owners and
Management

The
following table sets forth certain information regarding the ownership of the
Companys common stock as of March 31, 2001 by: (i) all those known by the
Company to be beneficial owners of more than five percent of its common stock;
(ii) each nominee for director; (iii) each of the executive officers named in
the Summary Compensation Table (provided above); and (iv) all executive
officers and directors of the Company as a group.

Name and Address of Beneficial Owner (1)
  Amount and Nature
  of Beneficial
  Ownership (2)
  Percent ofClass (3)Cell Genesys, Inc. (4)   342 Lakeside DriveFoster
  City, CA 94404
  8,954,136
  10.44%FMR Corp. (5)   82 Devonshire StreetBoston, MA
  02109
  8,821,044
  10.28Janus Capital
  Corporation (6)100 Fillmore StreetDenver,
  CO 80206-4923
  7,793,510
  9.08R. Scott Greer (7)
  877,400
  1.01M. Kathleen Behrens, Ph.D. (8)
  296,717
  *Raju S. Kucherlapati, Ph.D. (9)
  322,741
  *Mark B. Logan (10)
  120,933
  *Joseph E.
  Maroun (11)
  833,792
  *Stephen A.
  Sherwin, M.D. (12)
  348,490
  *Raymond M.
  Withy, Ph.D. (13)
  261,724
  *C. Geoffrey
  Davis, Ph.D. (14)
  223,575
  *Kurt W.
  Leutzinger (15)
  273,445
  *Gisela M. Schwab (16)
  146,741
  *All directors
  and executive officers as a group (16 persons) (17)
  3,934,097
  4.45%

*           Represents
beneficial ownership of less than one percent of the Company common stock.

(1)         Unless
otherwise indicated in these footnotes, the mailing address for each individual
is c/o Abgenix, Inc., 6701 Kaiser Drive, Fremont, California 94555.

(2)         This
table is based upon information supplied by officers, directors and principal
stockholders and Schedule 13Gs filed with the Securities and Exchange
Commission.  Unless otherwise indicated
in the footnotes to this table and subject to community property laws where
applicable, each of the stockholders named in this table has sole voting and
investment power with respect to the shares indicated as beneficially owned.

(3)         Applicable
percentages are based on 85,795,184 shares outstanding on March 31, 2001.

(4)         Based
on a Schedule 13G dated February 13, 2001.

(5)         In a
filing on Schedule 13G, dated February 13, 2001, Fidelity Management &
Research Company (Fidelity), a wholly-owned subsidiary of FMR Corp. and a
registered investment adviser, reported that it is the beneficial owner of
8,577,562 shares as a result of acting as investment adviser to various
registered investment companies (each a Fund or the Funds).  According to the disclosure contained in
Fidelitys Schedule 13G, (a) each of Edward C. Johnson 3d (Chairman of FMR
Corp.), FMR Corp. (through its control of Fidelity) and each of the Funds, has
sole power to dispose of the 8,577,562 shares owned by the Funds, (b) neither
FMR Corp. nor Edward C. Johnson 3d has the sole power to vote or direct the
voting of the shares owned directly by the Funds, which power resides with the
Funds Boards of Trustees, (c) Fidelity Management Trust Company, a
wholly-owned subsidiary of FMR Corp. and a bank, is the beneficial owner of
213,100 shares as a result of its service as investment manager to certain
institutional accounts, (d)  Edward C.
Johnson 3d and FMR Corp., through its control of Fidelity Management Trust
Company, each has sole dispositive power over 213,100 shares and sole power to
vote or to direct the voting of 182,630 shares owned by such institutional
accounts, and (e) Fidelity International Limited is the beneficial owner of
30,382 shares.

(6)         Based
on a Schedule 13G, dated February 16, 2001.

(7)         Includes
661,866 shares issuable upon exercise of options exercisable within 60 days of
March 31, 2001.

(8)         Includes
162,500 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(9)         Includes
292,741 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(10)       Includes
120,933 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(11)       Includes
5,602 shares owned by Mr. Marouns wife and 603,782 shares owned by the Maroun
Family Limited Partnership.  Mr. Maroun
disclaims beneficial ownership of such shares. 
Also includes 224,408 shares issuable upon exercise of options
exercisable within 60 days of March 31, 2001.

(12)       Includes
348,490 shares issuable upon exercisable of options within 60 days of March 31,
2001.  Does not include 8,954,136 shares
beneficially owned by Cell Genesys, Inc. (the CG Shares).  Dr. Sherwin is an officer, director and
beneficial stockholder of Cell Genesys, Inc. 
As such, he may be deemed to have voting and dispositive power over the
CG Shares.  However, Dr. Sherwin
disclaims beneficial ownership of the CG Shares for purposes of Section 13 of
the Exchange Act and this Amendment No. 1 to Form 10-K.

(13)       Includes
178,160 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(14)       Includes
173,575 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(15)       Includes
143,462 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(16)       Includes
141,875 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

(17)       Includes
2,675,507 shares issuable upon exercise of options exercisable within
60 days of March 31, 2001.

Item 13. Certain Relationships and Related Transactions

Certain Transactions

On
February 27, 1998, Mr. Leutzinger and Abgenix entered into a relocation loan
agreement pursuant to which Abgenix loaned $100,000 to Mr. Leutzinger in
exchange for a promissory note from Mr. Leutzinger secured by a deed of
trust.  No interest accrues on the
promissory note until June 30, 2003.  As
of December 31, 2000, the outstanding principal balance of the promissory note
was $100,000.

On
May 5, 2000, Dr. Schwab and Abgenix entered into a relocation loan agreement
pursuant to which Abgenix loaned $100,000 to Dr. Schwab in exchange for a
promissory note from Dr. Schwab secured by a deed of trust.  No interest accrues on the promissory note
until May 2005.  As of December 31,
2000, the outstanding principal balance of the promissory note was $100,000.

We
have entered into indemnity agreements with certain officers and directors
which provide, among other things, that we will indemnify such officer or
director, under the circumstances and to the extent provided for therein, for
expenses, damages, judgments, fines and settlements he or she may be required
to pay in actions or proceedings which he or she is or may be made a party by
reason of his or her position as a director, officer or other agent of Abgenix,
and otherwise to the full extent permitted under Delaware law and our Bylaws.

SIGNATURES

Pursuant
to the requirements of Section 13 or 15(d) of the Securities Exchange Act of
1934, the registrant has duly caused this amendment to be signed on its behalf
by the undersigned, thereunto duly authorized.

May
  15, 2001
  ABGENIX,
  INC.(Registrant)By:
  /s/ R. Scott GreerR. Scott GreerChief Executive Officer(On behalf of the registrant and asprincipal executive officer)