David Fajgenbaum: Surviving Castleman Disease and Reinventing Drug Discovery with AI

In this episode of Precision Signals, Sean Khozin sits down with Dr. David Fajgenbaum — physician, scientist, patient, and founder of Every Cure — to explore one of the most extraordinary stories in modern medicine. As a third-year medical student, David developed idiopathic multicentric Castleman disease, a rare inflammatory disorder that led to multi-organ failure. He was read his last rites five times. Facing a condition with no clear therapeutic roadmap, he began banking his own blood, performing proteomic analyses, and identified an mTOR pathway signal that led to a life-saving repurposed transplant drug. He has now been in remission for over a decade. But survival was only the beginning. David went on to found the Castleman Disease Collaborative Network and later co-founded Every Cure, a nonprofit using AI and computational pharmacophenomics to systematically evaluate every approved drug against every known disease. This episode is about moving from serendipity to strategy in medicine — and what it will take to build systems that leave no patient behind.