William

Executive Vice
President

Willem Jan Drijfhout, Ph.D., is Executive Vice President of Early Development Services and heads all early phase development and bioanalytical laboratory work for PRA. Dr. Drijfhout was Chief Scientific Officer for Pharma Bio-Research prior to the company being acquired by PRA in mid 2006. He joined Pharma Bio-Research in 1996 and became a member of the Executive Board in 1999.

Dr. Drijfhout has extensive experience in drug development and has been involved in the study design and conduct of several hundred Phase I studies.

Dr. Drijfhout holds a Ph.D. in Pharmacy.