Via Facsimile and U.S. Mail
 Mail Stop 6010


August 12, 2005


Mr. Peter Chambre
Chief Executive Officer
Cambridge Antibody Technology Group PLC
Milstein Building - Franta Park
Cambridge CB1 6GH
UNITED KINGDOM


Re:	Cambridge Antibody Technology Group PLC
	Form 20-F for the Fiscal Year Ended September 30, 2004
	Filed December 16, 2004
	File No. 000-31116


Dear Mr. Chambre:

	We have limited our review of your filing to those issues we
have addressed in our comments.  Where indicated, we think you
should
revise your document in response to these comments.  If you
disagree,
we will consider your explanation as to why our comment is
inapplicable or a revision is unnecessary.  Please be as detailed
as
necessary in your explanation.

	Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or on any other
aspect
of our review.  Feel free to call us at the telephone numbers
listed
at the end of this letter.

Item 5 - Operating and Financial Review and Prospects, page 42

1. Please refer to the Division of Corporation Finance "Current
Issues and Rulemaking Projects Quarterly Update" under section
VIII -
Industry Specific Issues - Accounting and Disclosure by Companies
Engaged in Research and Development Activities.  You can find it
at
the following website address:
(http://www.sec.gov/divisions/corpfin/cfcrq032001.htm#secviii).

Please disclose the following information for each of your major
research and development projects.

a. The costs incurred during each period presented and to date on
the
project;
b. The nature, timing and estimated costs of the efforts necessary
to
complete the project;
c. The anticipated completion dates;
d. The risks and uncertainties associated with completing
development
on schedule, and the consequences to operations, financial
position
and liquidity if the project is not completed timely; and finally,
e. The period in which material net cash inflows from significant
projects are expected to commence.

Regarding a., if you do not maintain any research and development
costs by project, disclose that fact and explain why management
does
not maintain and evaluate research and development costs by
project.
Provide other quantitative or qualitative disclosure that
indicates
the amount of the company`s resources being used on the project.

Regarding b. and c., disclose the amount or range of estimated
costs
and timing to complete the phase in process and each future phase.
To
the extent that information is not estimable, disclose those facts
and circumstances indicating the uncertainties that preclude you
from
making a reasonable estimate.

Financial Statements, page F-1

Report of Independent Registered Public Accountants, page F-1

2. Please provide a report, revised by your auditors, that
specifically refers to "the standards of the Public Company
Accounting Oversight Board (United States)", as required by
paragraph
3 of PCAOB Auditing Standard No. 1.

      As appropriate, please amend your filing and respond to
these
comments within 10 business days or tell us when you will provide
us
with a response.  If you disagree with any comment that calls for
disclosure, please provide us a letter prior to filing your
amendment
and we will consider your explanation as to why our comments are
inapplicable or a revision is unnecessary.  You may wish to
provide
us with marked copies of the amendment to expedite our review.
Your
letter should key your responses to our comments.  Detailed
letters
greatly facilitate our review.  Please file your letter on EDGAR
under the form type label CORRESP.  Please understand that we may
have additional comments after reviewing your amendment and
responses
to our comments.


	We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filing to be certain that the
filings include all information required under the Securities
Exchange Act of 1934 and that they have provided all information
investors require for an informed investment 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.

	In connection with responding to our comments, please
provide,
in your letter, a statement from the company acknowledging that

* the company is responsible for the adequacy and accuracy of the
disclosure in the filings;

* staff comments or changes to disclosure in response to staff
comments do not foreclose the Commission from taking any action
with
respect to the filing; and

* the company may not assert staff comments 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 our review of your filing or in
response to our comments on your filing.

      You may contact Keira Ino, Staff Accountant, at (202) 551-
3659
or Oscar Young, Senior Staff Accountant, at (202) 551-3622 if you
have questions regarding comments on the financial statements and
related matters.  Please contact me at (202) 551-3679 with any
other
questions.


Sincerely,



Jim B. Rosenberg
Senior Assistant Chief
Accountant
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Peter Chambre
Cambridge Antibody Technology Group PLC
August 12, 2005
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