Exhibit 1

Pursuant to Rule 13d-1(f)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Targeted Genetics Corporation.

This Agreement may be executed in any number of counterparts, each of which shall be deemed an original.

Executed this 17th day of April, 2003.

INTERNATIONAL BIOTECHNOLOGY TRUST PLC

By: /s/    Andrew Barker

Title: Director

SCHRODER INVESTMENT MANAGEMENT LIMITED

By: /s/    John Spedding                            

Title: Secretary

/s/    Tom Daniel                            

Tom Daniel

/s/    Kate Bingham                            

Kate Bingham

/s/    Eva Haas                            

Eva Haas