Favourable Decision in EPO Opposition Proceedings

CAMBRIDGE ANTIBODY TECHNOLOGY GROUP PLC
15 October 1999

For Further Information Contact:
Cambridge Antibody Technology Group plc
Dr David Chiswell, Chief Executive Officer       Tel: [phone]
Diane Mellett, Company Secretary/VP Legal Affairs
Rowena Gardner, Communications Manager


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City/Financial, Sue Charles/Rebecca Hennessy     Tel: [phone]
Trade/Science, Nikul Odedra               
       

FAVOURABLE DECISION IN EPO OPPOSITION PROCEEDINGS

Melbourn, UK Cambridge Antibody Technology ('CAT') reports that in a hearing
in Munich yesterday, the European Patent Office ('EPO') has upheld its
European patent 'Cloning Immunoglobulin Variable Domain Genes ' (Winter II)
which was the subject of opposition proceedings brought by MorphoSys of
Germany.  Claims 1-31 of the patent were unaltered by the proceedings and the
Opposition Division accepted a modification of Claim 32 proposed by CAT.

CAT has been advised that Morphosys' HUCAL Library is covered by the patent as
upheld at yesterday's hearing. 

Notes:

Cambridge Antibody Technology (LSE: CAT) is a UK biotechnology company using
its proprietary technologies in fully human monoclonal antibodies for drug
discovery and drug development.  Based in Melbourn, 10 miles south of
Cambridge, England, CAT currently employs around 150 people.  In March 1997,
CAT completed its initial public offering and listing on the London Stock
Exchange, raising approximately £41 million.

CAT has a world-leading platform technology for rapidly isolating fully human
monoclonal antibodies using phage display systems.  CAT has an extensive phage
display antibody library, currently incorporating around 100 billion distinct
antibodies. This library forms the basis for the company's strategy to develop
a portfolio of clinical development programmes and for discovering new drug
leads using functional genomics.  Three fully human therapeutic antibodies
developed by CAT are at various stages of clinical trials.

CAT has a number of license and collaborative agreements in place with
pharmaceutical and biotechnology companies including: Eli Lilly, Pfizer, BASF
Pharma, Genentech, ICOS Corporation, Genetics Institute/BASF Pharma,
Wyeth-Ayerst, Human Genome Sciences and AstraZeneca.

Opposition Procedures. European patents can be challenged at the European
Patent Office ('EPO') up to nine months after grant. The opposing party files
a written opposition to the patent, to which the Patentee can respond in
writing. After a preliminary ruling, by the Opposition Division ('OD'), the
parties may request Oral Proceedings to resolve the dispute. The Patentee may
submit a number of alternative claims (auxiliary requests) for consideration
should the OD object to the original claims. Either party may appeal against
the decision reached by the OD at Oral Proceedings. 

Related Legal Action. CAT has commenced legal proceedings against MorphoSys in
Germany. This action claims infringement by MorphoSys, not only of the Winter
II patent (the subject of this Opposition hearing), but also of another CAT
patent, McCafferty (display of scFv on phage). This legal action is ongoing.

Claim 32. Claim 32 now reads 'an expression library comprising a repertoire of
third CDR sequences, said sequences being located in an otherwise invariant VH
gene.'