Exhibit 10.50

SCHEDULE OF AMENDMENTS TO COMPENSATION ARRANGEMENTS FOR EXECUTIVE OFFICERS

1. Executive Compensation

Effective January 1, 2006, and pursuant to the annual review of base salary
compensation approved by the Compensation Committee of the Company’s Board of
Directors, base salaries for its executive officers were increased to the
amounts shown in the table below:

 

Name

  

Position

  

Currency of Salary

   Revised Annual Base
Salary Effective
January 1, 2006 Dr. David Fyfe    Chief Executive Officer    U. S. Dollars   
480,690 Daniel Abrams    Chief Financial Officer    British Pounds    187,775
Dr. Jeremy Burroughes    Chief Technical Officer    British Pounds    159,805
Dr. SB Cha (1)    Vice-President, Commercial    U. S. Dollars    280,000 Dr.
Scott Brown    Vice-President, Research    British Pounds    164,743 Stephen
Chandler    Vice-President, Legal and Intellectual Property    British Pounds   
200,619

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(1) Dr. Cha entered into a new employment agreement with us effective
February 1, 2006 and the salary shown was effective from that date.

2. Overseas Benefits Agreement with Dr. David Fyfe

The Company has noted that Dr. David Fyfe’s Employment Agreement was amended in
August 2004 to change its expiration date from August 2005 to August 2007.
Dr. Fyfe’s Overseas Benefits Agreement covers his assignment to the United
Kingdom and this agreement terminates three months after the Company notifies
Dr. Fyfe that his assignment to the United Kingdom is terminated. For the
avoidance of doubt, and notwithstanding the provision in the Overseas Benefits
Agreement for that agreement to expire in August 2005, the Company has confirmed
to Dr. Fyfe that, as was the intention of both Dr. Fyfe and the Company in
August 2004, the Overseas Benefits Agreement was extended to be coterminous with
his Employment Agreement at that time.