SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Expires: February 28, 2011 Estimated average burden hours per response 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* BEHRENS M KATHLEEN (Last) (First) (Middle) 6701 KAISER DRIVE (Street) FREMONT CA 94555 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ABGENIX INC [ ABGX ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 04/01/2006
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.0001 per share	04/01/2006		D		100,115	D	$22.5	0	D
Common Stock, par value $0.0001 per share	04/01/2006		D		31,800	D	$22.5	0	I	By Trust ( 1 )
Common Stock, par value $0.0001 per share	04/01/2006		D		7,151	D	$22.5	0	I	Dy Daughter
Common Stock, par value $0.0001 per share	04/01/2006		D		7,151	D	$22.5	0	I	By Son

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non- Qualified Stock Option (right to buy)	$1.5	04/01/2006		D			120,000	02/18/1998	02/18/2008	Common Stock, par value $0.0001 per share	120,000	( 2 )	0	D
Non- Qualified Stock Option (right to buy)	$3.5937	04/01/2006		D			30,000	06/02/1999	06/02/2009	Common Stock, par value $0.0001 per share	30,000	( 3 )	0	D
Non- Qualified Stock Option (right to buy)	$12.49	04/01/2006		D			10,000	06/04/2002	06/04/2012	Common Stock, par value $0.0001 per share	10,000	( 4 )	0	D
Non- Qualified Stock Option (right to buy)	$10.99	04/01/2006		D			15,000	06/27/2003	06/27/2010	Common Stock, par value $0.0001 per share	15,000	( 5 )	0	D
Non- Qualified Stock Option (right to buy)	$13.36	04/01/2006		D			15,000	06/07/2004	06/07/2011	Common Stock, par value $0.0001 per share	15,000	( 6 )	0	D
Non- Qualified Stock Option (right to buy)	$7.7	04/01/2006		D			20,000	06/13/2005	06/13/2012	Common Stock, par value $0.0001 per share	20,000	( 7 )	0	D

Explanation of Responses:

1. The shares are owned by an administrative trust, of which Dr. Behrens is a trustee and beneficiary.

2. This option was converted into an option to acquire 37,200 shares of Amgen Inc. common stock at an exercise price of $4.84 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

3. This option was converted into an option to acquire 9,300 shares of Amgen Inc. common stock at an exercise price of $11.60 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

4. This option was converted into an option to acquire 3,100 shares of Amgen Inc. common stock at an exercise price of $40.29 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

5. This option was converted into an option to acquire 4,650 shares of Amgen Inc. common stock at an exercise price of $35.46 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

6. This option was converted into an option to acquire 4,650 shares of Amgen Inc. common stock at an exercise price of $43.10 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

7. This option was converted into an option to acquire 6,200 shares of Amgen Inc. common stock at an exercise price of $24.84 per share pursuant to the terms of the Agreement and Plan of Merger, dated as of December 14, 2005, among Abgenix, Inc., Amgen Inc. and Athletics Merger Sub, Inc.

	/s/ George F. Fraley (Attorney-in-Fact)	04/01/2006
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.