Re Agreement

Cambridge Antibody Tech Group PLC
5 June 2001

01/CAT/10

FOR IMMEDIATE RELEASE

10.00 BST, 05.00 EST Tuesday 5 June 2001
For Further Information Contact:

Cambridge Antibody Technology                  Square Mile BSMG Worldwide
                                               (Europe)
Tel: [phone]
                                               Tel: [phone]
David Chiswell, CEO
                                               Kevin Smith
John Aston, Finance Director
                                               Graham Herring
Rowena Gardner, Head of Corporate
Communications
Xerion Pharmaceuticals GmbH                    BMC Communications/The Trout
                                               Group (USA)
Tel: [phone]
                                               Tel: [phone]
Fritz Rudert, Director of Strategic Alliances
and Licensing                                  Brad Miles, ext 17 (media)

Alexander Jaksch, Manager, Business            Brandon Lewis, ext.15
Development & Marketing                        (investors)



 CAMBRIDGE ANTIBODY TECHNOLOGY AND XERION PHARMACEUTICALS ANNOUNCE LICENSING
                   AGREEMENT FOR HUMAN ANTIBODY TECHNOLOGY



Melbourn, UK and Martinsried, Germany... Cambridge Antibody Technology (LSE:
CAT) and Xerion Pharmaceuticals GmbH today announce an agreement whereby CAT
will license its proprietary human phage antibody libraries and underlying
intellectual property to Xerion for target discovery, target validation and
functional proteomics. CAT receives a licence fee from Xerion in this initial
research agreement.

Dr. David Chiswell, Chief Executive Officer of CAT, commented 'Xerion is an
exciting company with tremendous future potential. CAT has long recognised
that one of the major challenges to drug discovery today is effective and
efficient validation of the drug targets of tomorrow. We feel that the
synergies between CAT's human antibody library technology and Xerion's
innovative approach to targeting protein function directly has the potential
to build significant future value.'

Dr. Markus Ewert, President and Chief Executive Officer of Xerion added, 'We
are excited to start this long-term relationship with CAT, a highly successful
and advanced company in the field of antibody phage display technologies and
development of therapeutic antibodies. CAT's antibody competence and Xerion's
XCALIburTM technologies will complement each other exceptionally well and thus
create powerful target validation tools.'

CAT has alliances with a large number of biotechnology and pharmaceutical
companies and has previously licensed its human antibody phage display
libraries to several companies, including Genentech, Pfizer, Eli Lilly, Human
Genome Sciences and Immunex.

Xerion Pharmaceuticals focuses on applying its technological leadership in
drug target validation partnerships and building its own pipeline based on
novel validated targets. Xerion has a number of its own and partnered
initiatives in the drug target discovery area. Its functional proteomics
platform directly addresses protein function, enabling target identification
and validation through antibody-based strategies and its core proprietary
technology, Chromophore Assisted Laser Inactivation (CALI).



                                    -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
    in Melbourn, 10 miles south of Cambridge, England, CAT currently employs
    around 220 people.

    CAT is listed on the London Stock Exchange, having raised £41m in its IPO
    in March 1997. A secondary offering in March 2000 raised £93m.

    CAT has a world-leading platform technology for rapidly isolating fully
    human monoclonal antibodies using phage display systems. CAT has an
    extensive phage 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.
    Four human therapeutic antibodies developed by CAT are at various stages
    of clinical trials.

    CAT has a number of licence and collaborative agreements in place with
    pharmaceutical and biotechnology companies including: Eli Lilly, Pfizer,
    BASF Pharma (Abbott), Genentech, ICOS, Genetics Institute, Wyeth-Ayerst,
    Human Genome Sciences, AstraZeneca, Pharmacia, Oxford GlycoSciences,
    Genzyme, Immunex, Zyomyx and Elan.



Xerion Pharmaceuticals


    Xerion Pharmaceuticals is a functional proteomics company dedicated to
    disease target validation. The company is based in Martinsried near
    Munich, Germany.

    Xerion Pharmaceuticals has recently completed its second financing round
    raising EUR11.1 million.

    Xerion Pharmaceuticals' integrated functional proteomics technology
    platform (XcelerateTM, XCALIbur TM, X-ploreTM) is focused on efficiently
    identifying and validating protein drug targets. Xerion is partnering its
    technology platform with pharmaceutical companies to assist in their drug
    discovery efforts. At the same time, the technology platform is being
    applied internally to the identification and validation of potential drug
    targets.

    Xerion Pharmaceuticals has license and partnering agreements with TILL
    Photonics GmbH, MDS Proteomics and several research institutes.



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.