Beginning in 1982, Dennis Fenton served in various capacities at Amgen, culminating in his role as Executive Vice President. Previously, he was employed by Pfizer Central Research from 1977 to 1981, working on new product development. He is a member of the American Society for Microbiology, the Society for Industrial Microbiology, the American Chemical Society, and the Parental Drug Association. Additionally, he is a Member of the Board of several companies, including Kythera Biopharmaceuticals, Inc., Dendreon Corp., XenoPort, Inc., Nora Pharmaceuticals, and Hospira. He holds a Doctoral degree in microbiology from Rutgers University.