I think phase 1 did not end early. They "reached all endpoints", which means they know they can measure what they set out to measure (in this case, whether the drug is dangerous).
I'm pretty sure this really means, "we weren't forced to stop testing before the last patient." So there wasn't anything that immediately went obviously wrong.
The trial isn't over yet, since observations are still being collected. E.g. They have to wait to see if the drug causes a delayed adverse reaction. Maybe those people will have their cochleas dissolve in January, etc.