Celltech Group PLC
25 April 2003


25 April 2003

                               CELLTECH GROUP PLC

Celltech Group plc was today informed that Merck is issuing the following press
release in respect of the discontinuation of Phase II studies of the lead
compound in their joint collaboration.

    'Merck Discontinues Development of Phosphodiesterase-4 (PDE-4) Inhibitor
                                    Compound


WHITEHOUSE STATION, N.J., April 25, 2003 - Merck & Co., Inc. announced today
that it is discontinuing development of its lead Phosphodiesterase-4 (PDE-4)
inhibitor compound, currently in Phase II clinical trials, for the treatment of
asthma and chronic obstructive pulmonary disease (COPD).  The company is
continuing its research in the field of asthma and COPD through the ongoing
study of other PDE-4 inhibitor molecules.  The timing for the development of
these other molecules is not certain.'


Enquiries:

For further information contact:

Celltech Group plc                                           +44 (0)1753 534 655
Dr Goran Ando, CEO
Peter Allen, CFO
Richard Bungay, Director of Corporate Communications


Brunswick London                                             +44 (0)20 7404 5959
Jon Coles
Fiona Fong


Brunswick New York                                               +1 212 333 3810
Cindy Leggett-Flynn


Celltech Group plc (LSE: CCH; NYSE: CLL) is one of Europe's largest
biotechnology companies, with an extensive late stage development pipeline and a
profitable, cash-generative pharmaceutical business. Celltech also possesses
drug discovery capabilities of exceptional strength, including a leading
position in antibody engineering. More details can be found at
www.celltechgroup.com.



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