Today I heard a heartbreaking story, in a recorded presentation by Roscoe Brady of the NIH, made at SENS 2 in 2005. He had a patient who was a little girl with Gaucher disease; and he had a treatment for the disease, which seemed to be safe in animal experiments. But the FDA wouldn't let him treat her until the primate experiments were done.
By the time the primate experiments were done, her brain had been irreparably damaged by Gaucher disease - as everyone involved had known it would be. Somehow the FDA decided it would be better to ensure her death, than to take the risk that she might have a bad reaction to the treatment.