FDA ODAC Meeting Material discussion analysis, page-7

it looks to me like FDA is pointing to technicality that the proposed MOA was not proven in the trial, even though the overall efficacy met targets. the other concern is that the batch consistency of product was measured against MOA attributes while these were somehow not proven in the trial. so reading between the lines it would seem that some other MOA was in effect that was neither identified nor measured, and therefore batch consistency could not be guaranteed in the manufacturing process since the key factor(s) are not identified or measured. I would imagine that MSB will be addressing these issues in a response but they are significant issues and the FDA acknowledges that the MOAs for MSC based therapies are extremely complex. all this in my own opinion and I'm not anywhere near qualified to comment on the science and topic.