MSB 2022 - The road to commercialisation, page-1336

In response to @dachopper's post above

NO!

The FDA, the company says, considers the potency assay reasonable. That is, prima facie, it looks like it measures a relevant analyte given the putative MOA. That is all!

When the data comes in, the agency will assess the proposed assay against the clinical data and the proposed MOA and decide whether to accept the assay as valid (in arriving at this decision, they will of course also look at the validation data relevant to the assay itself). So it's a huge step from reasonable to approved.

I am also not sure the agency will be swayed by the circular argument that runs "we trolled through the data for correlations and found this one which we are going to use to measure potency. And voila!, we find that the potency assay tracks the clinical response". Having established a potential potency assay would be a good starting point for a new trial using batches meeting the potency criteria (which, BTW, has to be established, ie only lots with potency greater than 'X' are released. So 'X' needs to be determined and validated).

As an aside following on from a post above by @pfeifer1982, one of the more curious comments in the agency submission to ODAC was that the sponsor had not submitted the raw data and the SAP for the post hoc analysis relevant to GvHD. I hope this time MSB has more confidence in the ability of its raw data to convince the regulator, failure to provide this basic data is a major red flag, hence the agency drawing attention to it!