Greg Keenan

Vice President, Medical Affairs & US Head Medical Officer


Greg is responsible for overseeing all US Medical Affairs activities for AstraZeneca and MedImmune. 

Prior experience

Greg began his career as a pediatric and adult rheumatologist, holding faculty, hospital and fellowship appointments at the Children’s Hospital of Philadelphia and the Hospital of the University of Pennsylvania. He then spent more than ten years with Centocor, Inc., performing roles of increasing responsibility in the Medical Affairs Department supporting the biologic compounds within rheumatology, gastroenterology, and dermatology therapeutic areas.

More recently, Greg served as the Vice President of Medical Affairs at Human Genome Services, Inc., launching the first biologic treatment for systemic lupus erythematosus.

He joined MedImmune in 2012 as the Senior Vice President of Medical and Scientific Affairs. In this role, Greg led a team of multiple departments including the Medical Science Directors field based team, Research and Policy, Operations and Medical Information services to support Synagis and Flumist/Fluenz.


  • Bachelor’s degree, Colby College, Waterville, ME
  • Medical degree, Albany Medical College, Albany, NY 
  • Boarded in pediatric and adult rheumatology