664. Are Thousands of Medical Cures Hiding in Plain Sight?

There is a horrible infectious disease that you have probably never heard of. It's called balamuthea. It's basically a brain eating amoeba. They don't really know how it's transmitted probably through some sort of soil exposure. It causes encephalitis, which is swelling in parts of the brain. It can kill you in relatively short order. It's extremely rare, and so there's been very little study of it. That is Heather Stone. She is a health science policy analyst in the Food and Drug Administration. The FDA has not approved any treatments for balamuthia, but that doesn't necessarily mean there aren't any treatments. Three or four years ago, a clinician in San Francisco at University of California treated the first patient with a drug called nitroxylin, which had been approved in Europe for fifty years for urinary tract infections. One preclinical study had shown off the chart amoebicidal activity that nobody had ever known about. You might not think that a UTI drug could treat a brain eating amoeba, but biochemistry can surprise you. A couple of years later, I got a call from a mother of a young girl who had been infected with balamuthia and was not expected to survive. And she was desperately trying to get a hold of nitroxylin. I was able to help get what's called an emergency IND, an investigational new drug application. Because the drug is not approved in The US, but it's approved in Europe, you have to get special permission from the FDA to use the drug. They sent the drug, and Elena had a pretty remarkable recovery. Now, I mean, it's not a miracle cure. There have been other patients who have received the treatment who have not survived. But for a disease that had a ninety percent fatality rate, to have two patients survive like that was pretty remarkable. There are 18,000 known human diseases, but only about a quarter of them have an FDA approved treatment. So is the story of balamuthia a story that could be replicated? How many more things are there that we could potentially uncover to save lives today? Because these drugs are already at the pharmacy. They're already manufactured. They're already available. Today on Freakonomics Radio, the economics of repurposed drugs with a special guest host Steve Levitt, my Freakonomics friend and co author who is a professor emeritus at the University of Chicago. And that episode starts now. This is Freakonomics Radio, the podcast that explores the hidden side of everything with your guest host, Steve Levitt. Hi. I'm Steve Levitt, and I'd like you to meet a doctor with an unusual life story. My name is David Fagenbaum, and I'm cofounder president of EveryCure and also a physician scientist at the University of Pennsylvania. David Fagenbaum grew up in North Carolina, his parents were from Trinidad, and his father was a surgeon. But he didn't always think that medicine would be his chosen path. When I was about eight or nine years …