CAT/HGS - Phase I trial

Cambridge Antibody Tech Group PLC
1 November 2001

01/CAT/19

FOR IMMEDIATE RELEASE

14.00 GMT 09.00 EST Thursday 1 November 2001
For Further Information Contact:

Cambridge Antibody Technology                 Weber Shandwick Square Mile
                                              (Europe)
Tel: [phone]
                                              Tel: [phone]
David Chiswell, Chief Executive Officer
                                              Kevin Smith
John Aston, Finance Director
                                              Graham Herring
Rowena Gardner, Head of Corporate
Communications

HGS                                           BMC Communications/The Trout
                                              Group (USA)
Tel: [phone]
                                              Tel: [phone]
David C Stump MD, SVP Drug Development
                                              Brad Miles, ext 17 (media)
Jerry Parrott, VP Corporate Communications
                                              Brandon Lewis, ext.15 (investors)
Kate De Santis, Director, Corporate
Communications & IR


 HUMAN GENOME SCIENCES ANNOUNCES PHASE I TRIAL OF A HUMAN MONOCLONAL ANTIBODY
                       DISCOVERED IN COLLABORATION WITH

                        CAMBRIDGE ANTIBODY TECHNOLOGY


Melbourn, UK... Cambridge Antibody Technology (LSE: CAT; NASDAQ: CATG) reports
an announcement today from Human Genome Sciences, Inc., (NASDAQ: HGSI) that
the US Food and Drug Administration has approved its Investigational New Drug
application to begin a phase I clinical trial for LymphoStat-B, formerly known
as Anti-BLyS. LymphoStat-BTM is the first antibody to a genomics-derived
target to enter clinical trials and was discovered and optimised in a
collaboration between CAT and Human Genome Sciences, as part of their first
alliance.

The trial will be a multi-centre, dose escalation study in patients with
systemic lupus erythematosus to determine the safety and pharmacology of the
drug in adult patients who are receiving standard therapies.

The full text of the Human Genome Sciences release and associated background
information can be found on the Human Genome Sciences website at 
http://www.hgsi.com


                                -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. Six 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.

In August 1999, CAT announced a collaborative agreement with HGS, expanded
into a ten-year collaboration agreement in March 2000. The original agreement
was based on utilising CAT's expertise in antibody development and high
throughput screening for up to three target human proteins identified by and
proprietary to HGS, in return for research funding. In addition, CAT stands to
receive milestone and royalty payments on products developed in the
collaboration. CAT is generating high potency, high affinity antibodies,
specific for HGS proteins discovered through its genomics programmes and
exploring their role in multiple disease indications for the development of
novel therapeutics. The first nominated target was the protein BLyS (B
Lymphocyte Stimulator), which has been implicated in a number of autoimmune
and neoplastic syndromes. The 10-year expansion of the collaborative alliance
with HGS involves joint research in the discovery and development of a wide
range of antibody-based therapeutics. The partnership involves the combination
and integration of HGS' gene sequence-based target discovery platform with
CAT's proteomics and antibody development technology. CAT received upfront
research funding from HGS as well as an equity investment.

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.