- Associate Professor, Department of Medicine (Translational Medicine and Human Genetics), Perelman School of Medicine, University of Pennsylvania
Dr. David Fajgenbaum is an Associate Professor of Medicine in the Division of Translational Medicine and Human Genetics at the Perelman School of Medicine, University of Pennsylvania, and a globally recognized leader in rare disease drug discovery and repurposing. He earned his MD, MBA, and MSc and built his career as a physician-scientist studying Castleman disease — a rare inflammatory disorder from which he himself nearly died and which he has helped redefine clinically and mechanistically.
Dr. Fajgenbaum founded and leads the Castleman Disease Collaborative Network (CDCN) and the Center for Cytokine Storm Treatment and Laboratory (CSTL) at Penn, and co-founded Every Cure, a non-profit using machine learning to systematically identify repurposing opportunities for approved drugs across rare diseases. His translational research established sirolimus as a treatment for idiopathic multicentric Castleman disease, transforming clinical care for a previously untreatable population.
Named to TIME’s 100 Most Influential People in Health in 2025, Dr. Fajgenbaum has built a model for patient-led, data-driven rare disease research that integrates academia, industry, and patient communities. He is an active member of the Penn Colton Center and the Institute for Immunology and Immune Health, where his focus on cytokine storm syndromes intersects directly with the Center’s broader work on systemic inflammation and autoimmunity.
