The FDA could create a standard consent form for nonapproved treatment that patients and doctors would sign, which would indemnify the physician from legal repercussions, but they don't, and they bear full blame for that. The AMA would still have its own regulations about the limits of ethical experimentation, with the revocation of a medical license as punishment to serious offenders, and malpractice safeguards could still be there. State laws about gross medical negligence are also an option.