PROPOSED MERGER OF BRITISH BIOTECH AND RIBOTARGETS

The boards of British Biotech and RiboTargets are pleased to announce that they
have agreed the terms of a Merger of the two companies to create a Merged Group
with a pro forma market capitalisation of £52 million and Net Cash as at 28
February of £43.5 million, with a further £7.9 million receivable from certain
RiboTargets shareholders upon completion of the Merger.

Rationale for the Merger

British Biotech and RiboTargets' are committed to creating shareholder value by
building a broader portfolio of discovery projects and clinical products, both
internally and through the acquisition of, or merger with, other companies.

The Directors of both companies believe that the benefits to shareholders
through the creation of the Merged Group include:

  • Complementary drug discovery and development skills

            - British Biotech's drug development expertise will be combined with
            RiboTargets' drug discovery capabilities

  • Stronger financial position

            - The Merged Group will have a robust balance sheet with Net Cash of
            £43.5 million as at 28th February 2003 and a further £7.9 million
            receivable from certain RiboTargets Shareholders at completion

  • Significant cost savings

            - Expected annual cash savings of approximately £6.4 million per
            annum, with savings of £3.1 million, net of costs to achieve these
            savings, in the 12 months to 30 April 2004

            - As separately announced today, British Biotech has agreed to
            transfer 17 employees to Evotec OAI Limited

            - Over time the Merged Group aims to reduce headcount from 177 to
            approximately 110 employees

  • Experienced management team

  • Well placed to participate in the further consolidation of the
    biotechnology sector

Key Merger terms 

The key terms of the Merger are as follows:

  • All share combination

  • Post completion ownership positions will be 50.01% British Biotech, 49.99%
    RiboTargets

  • Based on the price of the Existing Ordinary Shares as at close of business
    on 19 March 2003, RiboTargets was valued at approximately £26 million

  • Over 99% of RiboTargets shareholders have committed to accept the offer

  • Certain RiboTargets Shareholders have agreed to a six month lock-up
    following completion of the Merger and, for a further period of 14 months,
    certain orderly market provisions

  • British Biotech have proposed a 20:1 share consolidation to be executed
    prior to completion of, but not conditional on, the Merger

  • The transaction is expected to close on 23 April 2003

British Biotech has received a letter of intent to vote in favour of the
resolutions to implement the Merger from Amvescap plc in respect of a total of
170,380,248 British Biotech shares, representing approximately 25.5 per cent. of
the issued share capital of British Biotech.

The Merger is subject to, amongst other things, approval by British Biotech
Shareholders.

Proposed Board

Dr Peter Fellner                      Chairman (with executive responsibilities)
Simon Sturge                          Chief Executive
Anthony Weir                          Finance Director
Tim Edwards                           Corporate Development Director
Keith Merrifield                      Non-executive Director
Gene Williams                         Non-executive Director
Ian Kent                              Non-executive Director

Ian Kent, currently non-executive Chairman of RiboTargets, will join the British
Biotech Board as a non-executive director.

Philip Rogerson, currently a non-executive director of British Biotech, has
agreed to step down from the Board following completion of the Merger.

Commenting on today's announcement, Dr Peter Fellner, Chairman of British
Biotech, said:

'This Merger signals the first step in repositioning British Biotech as a
competitive commercial biotechnology company with the potential to create
significant value over time for our shareholders.'

Commenting on today's announcement, Simon Sturge, Chief Executive of
RiboTargets, added:

'The combination of RiboTargets and British Biotech will create a biotechnology
company with substantial discovery and development expertise and a sound
financial base. The Merger creates a platform for growth which will deliver
significant cost savings and position the Merged Group to participate in the
further consolidation of the biotech sector.'

This summary should be read in conjunction with the full text of the following
announcement. Appendix I contains sources of information and bases of
calculation and Appendix II contains the definitions of certain terms used in
this announcement.

There will be a presentation to analysts at 8.30 a.m. today at the offices of
JPMorgan, 10 Aldermanbury, London EC2V 7RF.

Should analysts be unable to attend the analysts' presentation in person, there
will be a dial in facility available. Details of this facility should be
obtained from Petra Alford on +44 20 7396 5373.

Enquiries

For further information contact the following:

British Biotech plc                       RiboTargets Holdings plc
+44 (0) 1865 781 166                      +44 (0) 1223 895 555
Dr Peter Fellner, Chairman                Simon Sturge, Chief Executive
Tim Edwards, Acting Chief Executive
Tony Weir, Finance Director