EXHIBIT 24


                  [LETTERHEAD OF CAMBRIDGE ANTIBODY TECHNOLOGY]

Dr Christopher Moyses
The Old Barn
Great Milton
Oxfordshire 0X44 7NF

                                                                 22 January 2003

Dear Dr Moyses

Service Agreement with Oxford Glycosciences plc

We are writing to you in relation to the proposed merger of Oxford Glycosciences
plc with Cambridge Antibody Technology Group plc ("the Merger"), which is
proposed to be effected by a scheme of arrangement pursuant to section 425 of
the Companies Act 1985.

Subject to and conditionally upon the Merger becoming effective by 30 April
2003:

(a)   we would propose that Clause 19.1 of your service agreement with Oxford
      Glycosciences plc dated 5 June 1998, as amended by letter dated 30
      September 2002 ("the Service Agreement") be varied to provide that you
      shall be entitled to give notice of your intention to terminate your
      employment at any time during the period of 12 months following the date
      upon which the Merger becomes effective and that such right shall not be
      conditional upon there having been any material and detrimental change, as
      described in Clause 19.1 of your Service Agreement;

(b)   in consideration of this, you agree (without prejudice to your continuing
      employment with Oxford Glycosciences plc) at our request made at any time
      to resign promptly from the board of Oxford Glycosciences plc and from the
      board of any member of the Oxford Glycosciences group of companies without
      any claim against Oxford Glycosciences plc or any of the members of the
      Oxford Glycosciences group of companies, whether in relation to your
      employment with or office as a director of such companies, arising from
      such resignations. Should you fail to do so, the board of Cambridge
      Antibody Technology Group plc shall be irrevocably authorised to appoint
      some person in your name and on your behalf to sign any documents and take
      such other steps as are necessary to give effect to such resignations.

For the avoidance of doubt, the above variation would apply only to the Merger
and not to any other change of control that may take place after the Merger has
been implemented.

We should be grateful if you would confirm your agreement to the proposed
variation by executing this letter below. This letter may be executed in
counterparts and by the parties to it on separate counterparts, each of which
when so executed and delivered shall be an original, but both counterparts shall
together constitute one and the same instrument.



EXECUTION

Dated 22 January 2003

SIGNED AND DELIVERED as a DEED by               )
JOHN ASTON, Director and DIANE MELLETT,         )  /s/ [Illegible]
Secretary duly authorised for and on behalf of  )  /s/ [Illegible]
CAMBRIDGE ANTIBODY TECHNOLOGY GROUP PLC         )


SIGNED AND DELIVERED as a DEED by CHRISTOPHER   )  /s/ C. Moyses
MOYSES in the presence of                       )


Witness' signature                      /s/ D. Mulhall
                                        ---------------------------------

Witness' name (in capitals)             DENIS MULHALL

Witness' Address                        FITZGEORGE HOUSE, FITZGEORGE AVE
                                        NEW MALDEN SURREY KT3 4SH

Occupation:                             FINANCE DIRECTOR