hopeforthefuture2, I am guessing (though far from sure) that the process of submitting this SAP to the FDA may be unusual because this SAP is a trailblazer for trials with non proportional hazard results where the number of survivors in the trial's tail is so impressive and the mOS and mPFS much less so.
I am guessing that most SAPs that deal with cancer treatments follow more or less routine guidelines and consultation with the FDA and other RA's prior to final submission is more limited because such SAPs follow previously well known guidelines.
However, this SAP may be a trailblazer and frequent back and forth consultation with the FDA is an indispensable step that ensures that this SAP is properly constructed and and does not fall of the rail. Once such consultations translate into finalizing the SAP, it may take very little time and effort for the FDA to approve the final draft.
Perhaps the FDA (and the other RAs) are already very busy in helping NWBO to construct a trail blazing SAP.
This is all just my guess based on zero experience and much intuition.