OK, I’ll have a crack at it! But I’ll emphasise at the start this is largely opinion – my preference in posting is to deal with facts rather than opinion so I am not entirely comfortable with this.
So where is Mesoblast with the FDA? The short answer is we don’t know. While meeting their statutory obligations, MSB has only provided limited information on their interactions with FDA, and much of it is confusing. We do know that there will be many interactions at multiple levels outside of the formal meetings, but we don’t know how far these have progressed. While the formal meetings are important, the real work and decisions occur outside of those forums.
FDA (OTAT) will most likely provide feedback on the new data prior to the resubmission – this is part of the normal pre-submission interaction with sponsors. MSB, in my view, would be reluctant in any case to resubmit without positive OTAT input.
Why do I say that? Well, there is an interesting bit of information in the FDA submission to ODAC. In it, FDA states that they provided feedback on the GvHD trial design to MSB, both positive and negative. Importantly, they state that they could not agree that the proposed null hypothesis was acceptable, that any submission needed to take into account the failed trials and that the trial does not appear to be an adequate and well-controlled study. MSB went ahead and submitted, with the CRL being the outcome. I believe that this time around, MSB will be extra cautious in considering FDA guidance.
This will also affect timeframe – I think MSB will not be taking any chances this time and that will extend the timeframe. My opinion is that we are several months away from OTAT feedback, given they do not yet have the data and it is a complex issue.
I do not believe there is a need for another ODAC review – the last one was very clinically focussed and they now have that input.
I wouldn’t necessarily bank on a shorter timeframe for the resubmission – there will be a lot of work in correlating the new data back to the trials and that may well pose additional questions so there will be a lot of to and fro. And, even if the FDA accepts the new CMC data, there are still some remaining efficacy issues to be addressed.
Apologies for being a bit long winded, but
@ddwn has raised some very pertinent questions, not sure I’ve been a lot of help in trying to answer them!
(20min delay)