Koman, I think the key to resolving my consternation over the way a blind would be treated under the previously discussed scenario before a recommended halt versus after a recommended halt, is that I must keep in mind the halt recommendation represents reaching the primary endpoint, if the primary endpoint is reached, there is no mystery regarding this because it must be announced if the halt is recommended. That we all know the trial is a success no longer must be hidden because the statistical endpoint is reached. Therefore, even if the blind is continued, it is done for the separate purpose of approval.
In other words, because, under this scenario, the treatment group's pfs advantage was proven over placebo, the only thing left to prove after the primary endpoint was reached and by the time accelerated approval arrives is how large that advantage proved to be. The blind normally does not remain in such a situation, but under one specific clause, the (less strict) blind can remain in order to arrive at/reach the median pfs (in this case) in the treatment group by the time accelerated approval happens.
In other words, a very strict blind is required to disprove the null hypothesis, but a less strict blind (aka: one where everyone knows the treatment has some efficacy) is required to demonstrate the full extent of that advantage.
In layman's term. The blind is more strict when one is initially trying to prove it works; after that, if you need to keep the blind for/until accelerated approval, the blind is less strict.
If this reasoning is sound, then a company can announce a halt recommendation from the DMC and simultaneously move forward to accelerated approval while keeping the blind -- albeit a less formal blind.
Respect Risk. Conduct Your Own Due Diligence. Manage your assets wisely. Diversify.
