Toinv wrote: "...the central issue to me is what defines the cohorts. If it is dosages that is one thing but did Don state that? If it is screening conditions like the state of the patients disease that is another important."

Recall that to arrive at the maximum tolerated dose and recommended phase 2 dose, that they had to perform the 3+3 dose escalation portion of the Phase 1 trial. Therefore, early cohorts started at lower doses relative to the later cohorts. But those early cohorts can move up to the next dose level after it is proven to not have dose limiting toxicities. Because of this progressive design, one can't just define cohort by their current dose but also must consider their past dose. Go back and look at some of their previous slide decks where they detail this 3+3 dose escalation design. That should alleviate any confusion you have. 

BearDownAZ