CAMBRIDGE ANTIBODY TECHNOLOGY/AMGEN RESTRUCTURE AGREEMENT.

Cambridge Antibody Technology Group plc (CAT), Cambridge, England, has announced the restructuring of an existing antibody development and marketing collaboration agreement with Immunex Corporation, subsequently acquired by Amgen Inc., in which Amgen takes over responsibility for the future development of the antibodies covered by the agreement. CAT will have the right to receive milestone and royalty payments upon the success of these programs.

Under the terms of the agreement, Amgen will take responsibility for the further development and marketing of the therapeutic antibody candidates isolated by CAT against two targets on which the parties agreed to collaborate and will bear all the associated costs. In return, CAT will receive from Amgen an initial fee and potential milestone payments and royalties on future sales.

One candidate has been delivered by CAT to Amgen. A second candidate is the subject of a continuing research program funded by Amgen and conducted by CAT and will be delivered to Amgen in due course.

Peter Chambre, CAT's CEO, commented, "We are delighted to have signed this agreement with Amgen. Over the last twelve months we have reviewed our product portfolio with the intention of focusing our investment on a number of core programs. This agreement allows us to do this, whilst retaining a significant interest in the success of the two antibody w candidates which CAT has helped to develop against Amgen targets."

Cambridge Antibody Technology (CAT)

* CAT is a UK-based biotechnology company using its proprietary technologies and capabilities in human monoclonal antibodies for drug discovery and drug development. Based near Cambridge, England, CAT currently employs around 280 people.

* CAT is a leader in the discovery and development of human therapeutic antibodies and has an advanced proprietary platform technology for rapidly isolating human monoclonal antibodies using phage display and ribosome display systems. CAT has extensive phage antibody libraries, currently incorporating more than 100 billion distinct antibodies. These libraries form the basis for the company's strategy to develop a portfolio of antibody-based drugs.

* Three CAT human therapeutic antibody products are now in clinical development, with two further product candidates in pre-clinical development.

* HUMIRA(TM), the leading CAT-derived antibody, isolated and optimized in collaboration with Abbott has been approved by the US Food and Drug Administration for marketing in the US and by the European Commission for marketing in the EU as a treatment for rheumatoid arthritis.

* Five further licensed CAT-derived human therapeutic antibodies in clinical development, with three further licensed product candidates in pre-clinical development.

* CAT has alliances with a number of pharmaceutical and biotechnology companies to discover, develop and commercialize human monoclonal antibody-based products. CAT has co- development programs with Amrad, Elan and Genzyme.

* CAT has also licensed its proprietary technologies to several companies. CAT's licensees include: Abbott, Amgen, Chugai, Human Genome Sciences, Merck & Co, Pfizer and Wyeth Research.

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

For more information, call 212/477-9007, ext. 17 or visit http://www.cambridgeantibody.com.