Dr. Breitmeyer has served as President, Chief Executive Officer and Director of Oncternal Therapeutics, Inc. since September 2015. Dr. Breitmeyer is a veteran biotech executive with experience successfully starting and growing biotechnology organizations. He has been responsible for both the development and implementation of both operational and drug development strategies, as well as supervising and managing both large organizations and emerging biotechnology companies. Dr. Breitmeyer served as President of Bavarian Nordic, Inc. and Executive Vice President of Bavarian Nordic A/S, a multinational corporation headquartered in Denmark, from February 2013 to July 2015 where he oversaw business operations and development strategy both for Bavarian Nordic, Inc. and Bavarian Nordic A/S. He served as a director of Zogenix, Inc., then a public pharmaceutical company, from March 2014 until it was acquired by UCB S.A. in March 2022 and was the acting Chief Medical Officer of Zogenix from August 2012 to February 2013 where he was responsible for clinical development and regulatory strategy. He previously served as the Executive Vice President of Development and Chief Medical Officer of Cadence Pharmaceuticals Inc., a public pharmaceutical company, from August 2006 to August 2012, and the Chief Medical Officer of Applied Molecular Evolution Inc., a wholly owned subsidiary of Eli Lilly and Co., a global pharmaceutical company, from December 2001 to August 2006. Dr. Breitmeyer was also the founder, President and Chief Executive Officer of the Harvard Clinical Research Institute, and Chief Medical Officer and Head of Research & Development for North America at Serono Laboratories Inc., an international biopharmaceutical company. Dr. Breitmeyer served as a founding collaborator and scientific advisor to Immunogen Inc., a biotechnology company, and held clinical and teaching positions at the Dana Farber Cancer Institute and Harvard Medical School. Dr. Breitmeyer earned his B.A. in Chemistry from the University of California, Santa Cruz and his M.D. and Ph.D. from Washington University School of Medicine and is Board Certified in Internal Medicine and Oncology. He holds an active California medical license.