what could go wrong?, page-122

here is a simpler earlier explanation with a very clear graph of failures breakdown. Less failures when done against active control . We have to be on better odds than run of the mill phase 3 as we are using a existing drug with known toxicity and side affects ( which is what stops killer dose ) and not some new drug that could throw up a random toxicity or side affect . Can still happen of course . .



http://www.missiontumor.com/2011/12/28-of-cancer-drugs-fail-phase-iii.html