It baffles me. On the bright side, by the time they reach a decision on dose they should have basically reviewed the clinical portion of the BLA. Coupled with having submitted the preclinical section months ago and having been granted rolling review, I cautiously expect the FDA to move relatively quickly once the BLA is in.
Heck, maybe I’m not giving the FDA enough credit. They could be considering this work on dosage as part of the rolling review. It IS the Christmas season, so I should be charitable.