Barbara J. Klencke, MD has served as the Chief Medical and Chief Development Officer of Sierra Oncology Inc. (NASDAQ: SRRA), a publicly traded clinical-stage biopharmaceutical company since 2015. Concurrently, she was an independent board member of Lexent Bio from 2017 until the company’s acquisition by Foundation Medicine in 2020. From 2011 to 2015 Dr. Klencke served as SVP, Global Development, at Onyx Pharmaceuticals, acquired by Amgen Inc., in 2013. She also led a variety of both early- and late-stage oncology programs while at Genentech, Inc. from 2003 to 2011. Throughout these years, she has played a major role in the successful development, approval and early commercialization of a number of important oncology products. She completed Internal Medicine and Hematology/Oncology training at the University of California, San Francisco and remained there as an Assistant Professor of Medicine in Oncology focusing on clinical research from 1995 – 2002. Dr. Klencke holds a BS from Indiana University and an MD from the University of California, Davis.