How A Doctor Cured His Own Terminal Disease | Dr. David Fajgenbaum

There are approximately 14,000 human diseases that currently do not have a single approved treatment.

"but there's still 14,000 diseases that don't have a single treatment right now." (said at 0:17:25)

Estimates of catalogued human diseases vary depending on the ontology used (such as Mondo, GARD, or Orphanet), typically spanning roughly 10,000 to over 14,000 distinct conditions, the vast majority of which are rare diseases. Systematic assessments and drug repurposing databases (e.g., Every Cure, MeDIC, and JAMA Network Open studies) note that over 9,500 to 10,000+ rare diseases alone lack any FDA-approved treatments, and only a minority of total cataloged human conditions have an approved therapy. While the ~14,000 figure is a commonly cited estimate for the overall number of disease concepts lacking an approved on-label therapy, the exact total depends on disease ontology definitions and classification granularity, and some of these conditions receive off-label or supportive medical treatments.

• partial: Rare Disease Drug Repurposing. (JAMA network open 2025) · cited 9x in the literature

  "Treatments are urgently needed for the more than 9500 rare diseases with no US Food and Drug Administration-approved therapies." (abstract, results, passage verified)

  pubmedfull study (doi)
• context: Medicines, Diseases, Indications, and Contraindications (MeDIC): a foundational resource t… (Nucleic acids research 2026)

  "Drug databases typically aim to provide reference information on medications and their uses but often lack strict definitions of the terms drug (e.g. approved or a clinical candidate) or disease, and do not focus on any specific context of use." (abstract, results)

  pubmedfull study (doi)

Eighty percent of the approximately 4,000 FDA-approved drugs are already off-patent and available as generic medications.

"And of the 4,000 drugs we have, 80% of them are already generic" (said at 0:17:31)

The speaker appears to blend two standard pharmaceutical metrics: the total pool of FDA-approved active drug substances/formulations (often cited in drug-repurposing libraries as ~2,000 to 4,000 FDA-approved chemical entities) and the proportion of generic drug utilization. In published literature and FDA regulatory reports, generics account for over 80% to 90% of all prescriptions dispensed in the United States (e.g., 84% in historical reviews of the Hatch-Waxman framework), and the majority of established small-molecule drugs approved over past decades are indeed off-patent.

• context: Hatch-Waxman Turns 30: Do We Need a Re-Designed Approach for the Modern Era? (Yale journal of health policy, law, and ethics 2015) · cited 20x in the literature

  "In 1984, Congress passed the Hatch-Waxman Act, which catalyzed the creation of the modem generic drug industry. Generic drugs today account for eighty-four percent of all prescriptions dispensed, but less than twenty percent of drug costs." (abstract, results, passage verified)

  pubmed