Jonathan joined Sofinnova Investments as an Executive Partner in 2020. With over 28 years of clinical development experience in the biotechnology and pharmaceutical industry he focuses on providing his strategic drug development expertise to aid companies from target identification to the market.
Prior to joining Sofinnova, Jonathan most recently served as Senior Vice President and Chief Medical Officer of Ascendis Pharma, a biotechnology company developing medicines for rare endocrine disorders. Previously Dr. Leff served as Executive Vice President, Research and Development at InterMune (acquired by Roche/Genentech in 2014) where he oversaw the development and US approval of Esbriet® (oral pirfenidone) for the treatment of idiopathic pulmonary fibrosis. Before InterMune, he was Chief Medical Officer at KaloBios Pharmaceuticals, and Vice President and Chief Medical Officer at Halozyme Therapeutics. Additionally, Dr. Leff held various positions at Roche, Amgen, and Merck. Jonathan earned a B.A. in Chemistry from the University of Pennsylvania, and received his M.D. from the University of Pennsylvania School of Medicine. He completed his medical training in Internal Medicine, Pulmonary and Critical Care Medicine at the University of Colorado, Denver.