I wonder what caused the sudden shift from "extend

I wonder what caused the sudden shift from "extending" the the current Phase 1 to "ending" it. What changed? Could it be that Dana Farber wanted to withdraw the current article from peer review until they could include data from the extended Phase 1 and Leo said "No"? Or perhaps they put in a request with the FDA to change the parameters of the Phase 1 and that request was denied?