If you design a Phase 2 to be a Pivotal Phase 2, is this type of trial to be considered to be a Phase 3 final result trial by the FDA, or do they consider this to be some sort of play on an accelerated approval?
If it is a non-randomized Phase II trial, the only thing that would persuade me to label it as "pivotal" is if it had a SPA. I think that's one thing we learned from the T-DM1 debacle.
I guess what I'm trying to get at is there an "overlap" in what is considered accelerated approval and can the FDA simply say, after results of a Pivotal Phase 2, "no. we need more. Spend another $20 million and 3 years and get back to us later."
The FDA can always back away from a Phase II SPA, particularly in terms of safety or scant clinically relevant efficacy. In cancer, the FDA hedges its bets in Phase II SPAs by never agreeing to a "sutiable" response rate (for example). Company's always say it needs to be "robust" and that the FDA never gave them a threshold. Perhaps coincidentally, most management teams describe a threshold above 25-30% as "robust".
From what I can recall, IMGN (with T-DM1) tried to get accelerated approval, I think? However, that trial, by design, wasn't a Pivotal Phase 2, it was just a wide randomized trial. The FDA declined approval and now results will not be out (in a drug which clearly worked) til 2012.
IMGN just licensed the technology to Roche Genentech, who was responsible for development and regulatory. Roche chose to not get a SPA on the single-arm Phase II and was rebuffed by the FDA via a Refuse To file (RTF) letter. I believe that was a BS decision demonstrating Pazdur's misunderstanding of personalized medicine. Further the RTF was not a regulatory issue, but a scintific and clinical issue that should have been addressed by ODAC.
So, even you design a huge Phase 2 double-blind, randomized trial (not a Pivotal), and results are overwhelming, would you be better off "calling" it a PIVOTAL trial (instead of just a regular P2), or do you need to talk to the FDA about this before hand?
Again, IMO it shouldn't be considered pivotal unless there is a SPA. I can see some limited exceptions in the orphan space.
Unless otherwise indicated, this is the personal viewpoint of David Miller and not necessarily that of Biotech Stock Research, LLC. We're on Twitter at BiotechStockRsr