As Dr. Mule pointed out, we have no idea how any of these works. If we wait until we do, we won't approve one of these drugs any time in the next decade or so. If 9902b shoots p<0.05, would you withhold approval because the MOA isn't precisely known? If the answer is no, then the MOA argument is moot.
It would seem to me that the whole MOA issue would mean more if this was a drug that was going to be given forever to a large population where forever represents decades (i.e., statins, etc) and where not knowing the MOA might potentially lead to unexpected SEs due to time and number of patients.
Here we are talking a very small number of years for folks who are dying.
Jon
PS Yeah, it could also mean more if one is questioning the efficacy effect as folks are. But given the safety data and the illness and the current ongoing study, does it?
I still think FDA might go with CU due and waiting given that is the POLITICALLY easiest answer to appease the different constituents.