Jonathan A. Leff M.D. — Chief Medical Officer and Senior Vice President at Ascendis Pharma A/S

Dr. Jonathan A. Leff, M.D. has been Chief Medical Officer of Ascendis Pharma A/S since February 25, 2016 and its Senior Vice President since March 03, 2016. Dr. Leff served as Executive Vice President of Research and Development at InterMune, Inc. from February 2012 to March 2015. Dr. Leff served as the Chief Medical Officer and Vice President at Halozyme, Inc. until October 2010. He served as the Chief Medical Officer of KaloBios Pharmaceuticals, Inc. from February 2011 to February 2012. He served as Chief Medical Officer and Vice President of Halozyme Therapeutics, Inc. from July 2009 to October 2010. He joined Halozyme in 2009. From 2007 to 2009, he served at Hoffmann-La Roche, Inc. (also known as Roche) as Vice President and Global Head of Inflammation Clinical Development and Disease Biology Leadership Team member and managed the worldwide clinical development programs for MabThera??/Rituxan??, ocrelizumab and Actemra??. From 2002 to 2007, Dr. Leff held various positions at Amgen Inc., including Vice President, North American Medical Affairs, where he led the medical affairs department consisting of 500 professionals and was responsible for oversight of post-registration studies in multiple therapeutic areas. At Amgen, he served as Senior Medical Director and Department Head of Osteoporosis Research, where he was responsible for conducting Phase 2 and 3 osteoporosis clinical trials for denosumab in over 10,000 patients, including a 7,800 patient fracture study. From 1994 to 2002, Dr. Leff served at Merck & Co., where he performed Phase 1 through Phase 4 clinical research studies for Singulair ??, a leukotriene receptor antagonist, which resulted in a global filing and regulatory approval. From 1984 to 1994, he trained and served in various positions at the University of Colorado, Denver, including director of the Outpatient Pulmonary Clinic. Dr. Leff received board certification in Internal Medicine, Pulmonary Medicine and Critical Care Medicine. Dr. Leff holds a bachelor's degree in Chemistry from the University of Pennsylvania and received his M.D. from the University of Pennsylvania School of Medicine.