lol. It's not an explicit rule. It's their revealed preference. They're incredibly slow to act on approvals, inflexibly demanding of "data" that is difficult

lol. It's not an explicit rule. It's their revealed preference. They're incredibly slow to act on approvals, inflexibly demanding of "data" that is difficult to obtain at best and completely unnecessary at worst, and they don't give a damn about the cost. (Both the near-term human cost, and the financial cost -- which goes on to reduce innovation in the drug business, leading to a further toll in human suffering.) In the end, they've killed an awful lot of people via inaction, lack of urgency, lack of efficiency. But that's okay, because killing people via inaction is not quackery, after all. Better a million die of neglect than another thalidomide, the FDA would say.