Dr Lewis recently served as CEO at Medistem Inc., a public regenerative medicines company.  He previously was President and CEO of Ambit Biosciences, a public biotechnology company.  Dr Lewis also served as CEO of the Juvenile Diabetes Research Foundation (JDRF) and Novocell (Viacyte), a regenerative medicines company focused on diabetes.  He was President of the Signal Research Division of Celgene after Celgene acquired Signal Pharmaceuticals, where he was CEO.  From 1979 to 1994, Dr. Lewis held a number of positions at Wyeth-Ayerst Research and its predecessor, Wyeth Laboratories, Inc., including Vice President of Research at Wyeth-Ayerst Research.

Dr. Lewis currently serves as Chairman of the Board of Cellastra Inc., a private biotechnology company, and director of four other private biotechnology companies, BioMarin Pharmaceuticals, Inc., Targazyme, Inc., Diavacs, Inc., and Habit DX.

Dr Lewis received a PhD in pharmacology from the University of Wales in Cardiff and completed a postdoctoral fellowship at Yale.  He was awarded an Honorary Fellowship from the University of Wales in Swansea.  He has published over 120 scientific manuscripts and edited five books.