How AI Drug Repurposing Creates Medical Miracles Without Commercial Backing
"If you use AI to come up with a new drug, you can make lots and lots of money. If you use AI to find a new use for an old, inexpensive drug, no one makes any money off of it," explains Dr. David Fajgenbaum, whose AI platform at the University of Pennsylvania has already saved multiple lives by identifying unexpected uses for existing medications.
This economic paradox stands at the heart of one of modern medicine's most promising frontiers, writes End of Miles, where breakthrough treatments discovered through artificial intelligence face minimal investment despite their proven ability to save patients deemed untreatable.
The Life-Saving Technology Nobody Wants to Fund
Dr. Fajgenbaum's journey into drug repurposing began with a desperate attempt to save his own life after being diagnosed with Castleman disease, a rare disorder that left him hospitalized with no effective treatments. His search led him to sirolimus, a generic medication typically given to kidney transplant recipients, which has kept his condition in remission for over a decade.
"I had this really clear realization that I didn't have a billion dollars and 10 years to create some new drug from scratch." Dr. David Fajgenbaum
But the UPenn professor quickly realized that systematically finding such hidden uses for existing drugs required a different approach. In 2022, he established Every Cure, a nonprofit dedicated to using machine learning to compare thousands of drugs against thousands of diseases simultaneously.
The Commercial Dead End for Life-Saving Discoveries
The fundamental problem, the medical researcher explains, is that pharmaceutical economics provides almost no incentive to discover new uses for drugs once they've gone generic. Once a drug's patent expires, competitive pricing drives down profits, making it commercially unattractive to pursue new medical applications—even when they could save countless lives.
This creates a stark contrast with traditional pharmaceutical development, where AI-driven discovery of entirely new compounds can generate billions in revenue through patent protection.
"If you use AI to find a new use for an old, inexpensive drug, no one makes any money off of it." Dr. Fajgenbaum
The economics expert Aiden Hollis, a professor at the University of Calgary who specializes in medical commerce, confirms this market reality. Once medications become part of the thousands of generics approved by the FDA, they typically face intense competition that drives down prices and profit potential.
Creating a New Funding Model
To overcome this fundamental economic gap, Fajgenbaum's Every Cure has pursued an alternative funding approach, securing over $100 million in commitments from TED's Audacious Project and the Advanced Research Projects Agency for Health (ARPA-H).
The UPenn team plans to use these funds to finance clinical trials of repurposed drugs—creating a pathway to validated treatments entirely outside the traditional pharmaceutical profit model.
Despite the commercial challenges, the physician-scientist remains convinced of the approach's transformative potential. Every Cure's platform currently compares approximately 4,000 drugs against 18,500 diseases, generating AI-powered scores based on the likelihood of efficacy. Once promising candidates are identified, a team of researchers conducts lab tests or connects with doctors willing to try the medications with patients who have no other options.
This approach has already yielded remarkable successes. For Joseph Coates, a 37-year-old Washington state resident given only days to live due to a rare blood disorder called POEMS syndrome, an AI-suggested combination of therapies led to a complete remission within months.
"There is a treasure trove of medicine that could be used for so many other diseases. We just didn't have a systematic way of looking at it. It's essentially almost silly not to try this, because these drugs are already approved. You can already buy them at the pharmacy." Donald C. Lo, scientific lead at Remedi4All
