Re Alliance

Cambridge Antibody Tech Group PLC
10 October 2001


01/CAT/18

Embargoed until 07.00 BST 02.00 EST Wednesday 10 October 2001
For Further Information Contact:

Cambridge Antibody Technology

Tel: [phone]                         Square Mile BSMG Worldwide
                                                  (Europe)

David Chiswell, Chief Executive Officer           Tel: [phone]

John Aston, Finance Director                      Kevin Smith

Rowena Gardner, Head of Corporate Communications  Graham Herring

Merck and Co., Inc.                               BMC Communications/The Trout
                                                  Group (USA)
Tel: [phone]
                                                  Tel: [phone]

Janet Skidmore, Director Merck Research
Laboratories Public Affairs                       Brad Miles, ext 17 (media)

                                                  Brandon Lewis, ext.15
                                                  (investors)





  CAMBRIDGE ANTIBODY TECHNOLOGY ANNOUNCES PRODUCT DEVELOPMENT ALLIANCE WITH
                              MERCK & CO., INC.

    Collaborative programme to develop novel drugs for the prevention and
                 treatment of HIV-mediated infectious disease

Melbourn, UK... Cambridge Antibody Technology (LSE: CAT; NASDAQ: CATG)
announces today that it has entered into a collaboration and license agreement
with Merck & Co., Inc. (NYSE: MRK) for the research and development of
products specific for a key target involved in disease mediated by HIV.

Under the terms of the five-year agreement, Merck will provide proprietary
technology and experience in HIV biology and CAT will provide its proprietary
human phage antibody libraries. Merck receives exclusive rights to
prophylactic and therapeutic products developed in collaboration with CAT
against the specified viral target. CAT will receive an upfront technology
access fee from Merck, clinical development milestones and royalties on the
sale of products based on both human monoclonal antibodies and on non-antibody
products validated using the CAT technology.

Dr. David Chiswell, CEO at CAT, commented 'This new alliance with Merck, a
global leader in microbial vaccine research, presents CAT with an exciting
opportunity to share in the future success of antiviral drug development. CAT
is committed to addressing unmet medical need through the discovery,
development and commercialisation of novel antibody-based drugs. As CAT's
first product development initiative in infectious disease, this alliance with
Merck broadens the potential impact of CAT's proprietary technologies by
examining both antibody and non-antibody approaches to the prevention and
treatment of HIV infection and disease. CAT is extremely pleased to be Merck's
first partner for research and development of human monoclonal antibodies,
particularly in a disease area as challenging as AIDS, and looks forward to
sharing in the future rewards of this alliance'.

                                    -ENDS-

                              Notes to Editors:

Cambridge Antibody Technology (CAT)

CAT is a UK biotechnology company using its proprietary technologies in human
monoclonal antibodies for drug discovery and drug development. Based near
Cambridge, England, CAT currently employs around 250 people.

CAT is listed on the London Stock Exchange and on NASDAQ since June 2001. CAT
raised £41m in its IPO in March 1997 and £93m in a secondary offering in March
2000.

CAT has an advanced platform technology for rapidly isolating human monoclonal
antibodies using phage display systems. CAT has an extensive phage antibody
library, currently incorporating more than 100 billion distinct antibodies.
This library forms the basis for the company's strategy to develop a portfolio
of antibody-based drugs and to utilise antibodies as tools for target
validation. Five human therapeutic antibodies developed by CAT are at various
stages of clinical trials.

CAT has alliances with a large number of biotechnology and pharmaceutical
companies to discover

develop and commercialise human monoclonal antibody-based products. CAT has
also licensed its

proprietary human antibody phage display libraries to several companies for
target validation and drug discovery. CAT's partners include: Eli Lilly,
Pfizer, BASF Pharma (Abbott), Genetics Institute, Wyeth-Ayerst, Human Genome
Sciences, Pharmacia, Oxford GlycoSciences, Genzyme, Immunex, Zyomyx, Elan and
Xerion.



Merck & Co., Inc.

Merck & Co., Inc. is a leading research-driven pharmaceutical products and
services company. Merck discovers, develops, manufactures and markets a broad
range of innovative products to improve human and animal health, directly and
through its joint ventures. Merck-Medco manages pharmacy benefits for
employers, insurers and other plan sponsors, encouraging the appropriate use
of medicines and providing disease management programs. Through these
complementary capabilities, Merck works to improve quality of life and contain
overall health-care costs.



Prophylatic: an agent that prevents the development of a condition or disease



This press release contains statements about Cambridge Antibody Technology
Group plc (CAT) that are forward looking statements. All statements other than
statements of historical facts included in this press release may be forward
looking statements

These forward looking statements are based on numerous assumptions regarding
CAT's present and future business strategies and the environment in which CAT
will operate in the future. Certain factors that could cause CAT's actual
results, performance or achievements to differ materially from those in the
forward looking statements include: market conditions, CAT's ability to enter
into and maintain collaborative arrangements, success of product candidates in
clinical trials, regulatory developments and competition.