I do not believe that the SAP need be "accepted" as you say or at least formally accepted by any RA. Of course, any RA is free to provide guidance but the final SAP submitted is up to the applicant. Secondly, this is an orphan designation and in such cases free intercourse between the applicant and FDA, at least, is highly encouraged between the parties. I am reasonably certain that NWBO has known for some time and planned to update the SAP in view of developments and concerns about the original endpoints which as it turns out are not entirely suitable for immunological trials, as well as the confoundment/crossover issues attending these endpoints. Accordingly, I am equally certain that during their interchanges with the FDA(and the other 3 RAs), the updating and modifications to the original SAP were discussed and guidance sought and given. And this interchange continued during the actual preparation of the modified SAP. Hence, it is not as though the RAs are seeing these modifications for the first time. I am reasonably sure that they have had a "heads up" for some time. It would have been foolish for NWBO to proceed with modifications in isolation which resulted in the size of a telephone book without relatively frequent back and forth with the affected agencies. Further, I do not believe that the RAs need to agree on the overall submission. Each RA, if they have given guidance, will be interested in seeing their own guidance suggestions incorporated in the SAP. They may have relatively little interest in the guidance given by other RAs, which in any event may be relatively similar and, in any event, would not be required or even suggest final agreement between and among these sui juris agencies. Thus, I think that most of the guidance such that may have been issued was already and largely incorporated in the SAP as the process went along and accordingly, any final review of the submission would be relatively fast paced.
I believe that the RAs are not a significant pacing item if my above analysis is reasonably accurate. In fact, I think that any delays have more to do with NWBO in completing and the submitting the final draft. It may be, even likely, that the SAP is still not finally completed or has been completed only recently. I also think that NWBO has always planned to delay unblinding until 4 years past final enrolments and that is why the secrecy and lack of transparency. JMHO.
