Generation Bio Co. Appoints Tracy Zimmermann, Ph.D., Appointed as Chief Development Officer and Doug Kerr, M.D., Ph.D., MBA, Appointed as Chief Medical Officer. Tracy previously served as vice president, preclinical research and translational biology. Prior to joining the company, Dr. Zimmermann held a variety of R&D roles over a 15-year tenure at Alnylam Pharmaceuticals. She received her Ph.D. from the University of Colorado at Boulder. Doug joined Generation Bio in 2017 and has led R&D operations and strategic development of the company’s portfolio. He received his M.D. and Ph.D. from Jefferson Medical College and his MBA from Princeton University.