Cambridge Antibody Tech Group PLC
01 April 2003
                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES

1)   Name of company
Cambridge Antibody Technology

2)   Name of shareholder having a major interest
Wellington Management Company, LLP

3)   Please state whether notification indicates that it is in respect of
holding of the shareholder named in 2 above or in respect of a non-beneficial
interest or in the case of an individual holder if it is a
holding of that person's spouse or children under the age of 18
Non Beneficial

4)   Name of the registered holder(s) and, if more than one holder, the
number of shares held by each of them

Interests held in various accounts (the 'Accounts') for which
Wellington Management Company acts as a discretionary investment manager
- names of the Accounts not disclosed.

5)   Number of shares/amount of stock acquired
612,283

6)   Percentage of issued class
1.68%

7)   Number of shares/amount of stock disposed
Nil

8)   Percentage of issued class
Nil

9)   Class of security
Ordinary 10p shares

10)  Date of transaction
Not disclosed

11)  Date company informed
31 March 2003

12)  Total holding following this notification
1,762,336

13)  Total percentage holding of issued class following this notification
4.85%