There's a medical documentary on YouTube, called Drug Trial Goes Terribly Wrong: Emergency at the Hospital on a channel called Real Stories.

It's about a drug trial in the UK for a possible treatment of leukemia, which had positive results in monkeys. The reactions to the drug were severe swelling (newspaper called one guy the Elephant Man), multiple organ failure, high fevers, and several fingers/toes were amputated. Lasting effect is possible fertility issues. There was a police investigation to ensure that the drug wasn't tampered with, patients weren't intentionally poisoned, correct dosages, etc.