This is not a scientist writing, but a zealot trying to defend a religious position to himself by writing his Boswell. See Dendreon's Dilemma by Herper
This does not justify the FDA's deadly decision to delay Provenge but it speaks volumes about the slavish mindset regarding clinical trials -- both inside and outside the agency and how to determine safety and efficacy. A bigger push to change the paradigm to evaluate personalized treatments -- of which cancer immunotherapies are a subset -- is needed.
That said, Fleming's publish confession of anguish reminds me of Cotton Mather who sought to unburden his soul after unleashing the Salem Witch trials. Don't give us this "I was doing it for the cancer patients." This is you protecting the probabilistic priesthood by offering up sacrificial lambs.