Using Existing Drugs in New Ways to Treat & Cure Diseases of Brain & Body | Dr. David Fajgenbaum

Episode Summary

Executive Summary: Andrew Huberman and Dr. David Fagenbaum discuss how many effective treatments may already exist for diseases but remain overlooked because medicine is fragmented, under-incentivized, and not systematically mapped. Fagenbaum shares his near-fatal Castleman’s disease journey, the repurposed drugs that saved him, and how Every Cure uses AI and evidence review to match existing drugs to diseases faster and more rigorously.

Main Topics: Drug repurposing as a hidden engine of medicine (Priority: 5/5): Fagenbaum argues that many approved drugs have unrecognized effects across pathways and diseases, and that repurposing can reveal life-saving uses already sitting on pharmacy shelves. Information asymmetry and the limits of traditional care (Priority: 5/5): The conversation emphasizes that doctors, patients, and even experts often miss available treatments because knowledge is scattered across papers, specialties, and countries. Fagenbaum’s Castleman’s disease survival story (Priority: 5/5): His experience with repeated relapses, multi-organ failure, and being told he was out of options became the driving force behind his mission to find repurposed therapies. Every Cure’s AI-driven discovery pipeline (Priority: 4/5): Fagenbaum describes a nonprofit that scans drug-disease possibilities using biomedical knowledge graphs and machine learning, then validates promising hits in lab and clinical settings. Examples of successful repurposing (Priority: 4/5): The discussion covers aspirin, Viagra, lidocaine, thalidomide, colchicine, rapamycin, TNF inhibitors, and others to show how old drugs can become new treatments. Patient agency, advocacy, and finding expert networks (Priority: 4/5): Listeners are encouraged to contact disease organizations, seek world experts, and keep asking questions rather than passively accepting a single opinion. Hope, action, and resilience under illness (Priority: 3/5): Fagenbaum reflects on endurance, family support, sports discipline, and a feedback loop of hope-action-impact that helped him survive and stay mission-driven.

Key Arguments: Many effective therapies are already approved for other conditions and could be repurposed to treat diseases currently considered untreatable. The medical system is not structured to systematically search for new uses of old drugs, especially once drugs go generic and commercial incentives vanish. Doctors often practice from partial, piecemeal evidence; therefore, patients should seek disease-specific organizations and top experts. AI is best used not as a replacement for clinical judgment, but as a tool to connect existing research findings and prioritize the most promising drug-disease matches. Repurposed drugs should still be tested rigorously in labs, observational studies, and clinical trials before broad recommendation. Fagenbaum’s own survival came from drugs made for other diseases, reinforcing his belief that existing medicines should be matched to any patient who can benefit. The goal is not speculative self-treatment, but a more systematic and evidence-based way to surface hidden uses of medicines. Patient outcomes can depend heavily on knowledge networks; access to the right expert or group can literally determine survival.

Data Points: FDA-approved drugs: 4,000 - Fagenbaum says there are about 4,000 FDA-approved drugs. Diseases treated by approved drugs: about 4,000 - He notes those drugs are approved for roughly 4,000 diseases. Untreated diseases: 14,000 - He says there are still about 14,000 diseases without a single treatment. Generic drugs: 80% - He states that 80% of approved drugs are generic, reducing incentives to study new uses. Small-molecule protein binding: 20-30 proteins - He says an average small-molecule drug can bind multiple proteins, which helps explain side effects and repurposing potential. Lidocaine breast cancer trial size: 1,600 patients - An India trial of lidocaine around tumor surgery in localized breast cancer. Lidocaine mortality reduction: 29% at 5 years - Reported reduction in mortality for women receiving lidocaine before surgery. Angiosarcoma responders to PD-L1 signal: 4 of 5 tumors - A 2013 paper found increased PD-L1 expression in four of five angiosarcoma tumors. Angiosarcoma outcome improvement: about 18% to 20% beyond 1 year - Fagenbaum says PD-1 inhibitor treatment changed a uniformly fatal cancer into one where around 18-20% live beyond a year. Castleman’s relapses before rapamycin: 5 near-death episodes - Fagenbaum says he nearly died five times before starting sirolimus/rapamycin. Time in remission on rapamycin: 11 and three-quarters years - He reports being in remission for nearly 12 years on sirolimus. Every Cure active programs: 9 - Fagenbaum says the nonprofit has nine active programs. Disease coverage goal: 18,000 human diseases - He describes Every Cure as aiming across all 18,000 human diseases. Blood biomarkers tested by Function ad: 100+ - Sponsor segment mentions advanced lab testing across more than 100 biomarkers.

Pivotal Quotes: "I just believe that the 4,000 drugs we have today should help all the patients who can benefit from them. Period." — Dr. David Fagenbaum: His core mission statement on why drug repurposing should be systematic and universal. "There was nothing more that we can do." — Doctor in Fagenbaum's story: The moment that triggered Fagenbaum’s commitment to finding hidden treatment options after repeated relapses. "No one should suffer if there's a drug at your CVS that could help you." — Dr. David Fagenbaum: He argues that effective treatment should not remain inaccessible simply because the drug is generic or repurposed.

Implications: Medicine needs better databases, AI prioritization, and stronger translation from published evidence to practice. For patients, the message is to advocate, seek experts, and ask about repurposed options; for industry and science, the opportunity is systematic matching of existing drugs to overlooked diseases.