Agreed ATL and Flipper.
The ethical reasoning is clear and I have been saying for a long time that 1) I believed the halt was ethical, for the benefit of the PLACEBO arm, not the patients receiving DCVax- (Purely speculation on my part); 2) that unfortunately it was likely that the problem with the judgment that the placebo arm was not getting the best care at that point was that they could not stop the trial for efficacy because you still need to prove efficacy and they did not have what they needed yet; 3) the FDA recognized the regulatory unreasonableness of the circumstance and would likely address this ultimately because you can't really tell applicants to do one thing, then to do another thing (the opposite thing), and then tell them they are not approved because they did not keep doing the first thing which you told them to stop doing (it's actually the law, regulators can't be that irrational); 4) when the updated guidance on external controls came out, I explained that their keenness about it suggested to me that this was the FDA's likely guided fix to the circumstance, which they recognized was a real issue for treatments that should be likely approved but might face unnecessary regulatory hurdles.
That's the quick way of saying that the FDA would not want to fail a product that is obviously efficacious (despite a challenge in the trial due to regulatory hurdles that were not well crafted to achieve the regulator's primary end), but where the regulatory process itself got in the way of fully proving what had become obvious from the facts. The regulatory process had to be reformed (which they are doing with the 21st Century Cures Act), to allow for reasonable scientific evidence to be introduced. Dr. Liau had been talking about historical evidence for some time before the FDA guidance was updated. That does not just happen, that is likely the result of a long conversation between the FDA and many researchers over years, and then the acuteness of this particular trial seems maybe to have gotten the FDA to act (as well as the authorization of the 21st Century Cures Act). I do not think this is the only trial to have issues with a placebo arm and the treatment arm being so divergent, for such a difficult disease, but I do think it was likely more acute.
Now this is all me guessing, deductive reasoning and a lot of experience with regulators in the past and I don't naturally distrust every regulator I see. I am not going to quote the regulators, or the FDA, I've done it in the past. In my own experience, I've been in communication with regulators over the years working through issues and challenges and worked through how to address what otherwise might be a regulatory challenge and make it a win-win for all stakeholders. Primary regulators, in my experience, tend to like parties that are working with them to solve problems. It is actually the positive side of their job.
This is the lens through which I have viewed many events, and I could very well be wrong on some of it. But, I'm pretty sure the FDA guided them on the external controls and updating their SAP, in my opinion. The reality is that parties seek to discuss many things at different levels of formality and informality with regulators. It might be a formal call, a submission, there are lines for counsel to call on matters that are questions with no assurances of course, and regulators do appear at conferences and events where questions can be asked and they can be queried on their mindsets. There are many ways that lawyers and parties can get into the minds of regulators though I expect these steps came with direct communications mostly.
