Mail Stop 0309

							March 30, 2005


William R. Ringo
Chief Executive Officer
Abgenix, Inc.
6701 Kaiser Drive
Fremont, California 94555

Re:	Abgenix, Inc.
	Registration Statement on Form S-3
	File Number 333-123390

Dear Mr. Ringo:

	This is to advise you that we are not conducting a full
review
of the above registration statement.  However, we will be
reviewing
the accounting disclosure in your Form 10-K for the period ended
December 31, 2004.  You will receive our accounting comments under
separate cover.  All comments will need to be fully resolved
before
we take final action on the registration statement.

	Also, we note that your Form 10-K is not yet complete because
your proxy statement, which is going to include the Form 10-K Part
III information, has not yet been filed.  You will need to file
this
information, either in the proxy statement or in an amended Form
10-
K, before we declare your registration statement effective.

	We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have made.

	Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:

* should the Commission or the staff, acting pursuant to delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;

* the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and

* the company may not assert this action as a defense in any
proceeding initiated by the Commission or any person under the
federal securities laws of the United States.

	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

	We will consider a written request for acceleration of the
effective date of the registration statement as a confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.

	Please contact Greg Belliston at (202) 824-5219 or me at
(202)
942-1840 with any questions.

							Sincerely,



							Jeffrey P. Riedler
							Assistant Director

cc:	William H. Hinman, Jr., Esq.
	Simpson Thacher & Bartlett LLP
	3330 Hillview Avenue
	Palo Alto, CA 94304
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William R. Ringo
Abgenix, Inc.
March 30, 2005
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