Peter A. Prieto, M.D., M.P.H.

Peter A. Prieto, M.D., M.P.H., joined Lyell as our Senior Vice President, Medical Affairs in August 2026. Prior to Lyell, Dr. Prieto served as Senior Vice President, Medical Affairs at Tempus AI. Before Tempus, he was Senior Vice President, Global Medical Affairs at Iovance Biotherapeutics, where he built the medical affairs function to support the launch of the first approved tumor-infiltrating lymphocyte (TIL) cell therapy. Earlier, Dr. Prieto was a surgical oncologist and surgeon-scientist at the University of Rochester, where he led an independently funded laboratory studying tumor heterogeneity, immunotherapy resistance, and biomarkers of response to cellular immunotherapy. He trained at the National Cancer Institute’s Surgery Branch under Steven A. Rosenberg, M.D., Ph.D., where he participated in early first-in-human trials of adoptive cell therapy, including TIL and CAR T-cell therapies, for patients with advanced solid tumors. A board-certified surgical oncologist, Dr. Prieto completed his fellowship in Complex General Surgical Oncology at The University of Texas MD Anderson Cancer Center and his general surgery residency at Yale University School of Medicine, where he served as Chief Resident. He earned an M.D. and M.P.H. from St. George’s University.