Blocklisting Interim Review

Cambridge Antibody Tech Group PLC
30 September 2005

                        BLOCK LISTING SIX MONTHLY RETURN



Information provided on this form must be typed or printed electronically.



To:  The FSA



Date: 30 September 2005


Name of applicant:                               Cambridge Antibody Technology 
                                                 Group plc

Name of scheme:                                  Company Share Option Plan

Period of return:    From:     1 April 2005      To:    30 September 2005

Balance under scheme from previous return:       266,232

The amount by which the block scheme             Nil
has been increased, if the scheme has been 
increased since the date of the last return:

Number of securities issued/allotted under       25,854
scheme during period:

Balance under scheme not yet issued/allotted     240,378
at end of period

Number and class of securities originally        22,136,251 ordinary 
listed and the date of admission                 10 pence shares
                                                 25 March 1997

Total number of securities in issue at           51,639,868
the end of the period


Name of contact:                                 Justin Hoskins

Address of contact:                              Milstein Building, Granta Park, 
                                                 Cambridge CB1 6GH

Telephone number of contact:                     01223 471 471



SIGNED BY   Justin Hoskins, Company Secretary

Director/company secretary/suitably experienced employee/duly authorised
officer,

for and on behalf of



Cambridge Antibody Technology Group plc

Name of applicant



If you knowingly or recklessly give false or misleading information you may be
liable to prosecution.


                      This information is provided by RNS
            The company news service from the London Stock Exchange