Foaming the runway for less than ideal news? I note that language "various special circumstances..." is new in the 10-Q (5/10/19) and did not appear in the 10-K (4/2/19) or the previous 10-Q (11/16/18).
It might mean that a phase is taking longer than expected, which I doubt would surprise anyone here. It might mean they are running into serious data/statistical complications. Could be anything in between, or perhaps a bit of both.