The answer (by interjay) to this similar question suggests you can add hints like:
if 0: foo = Bar()
in places where you're used to using
assert isinstance(foo, Bar)
Not as pretty, of course...
EDIT: it works for me, with Komodo Edit 6.0.3 and Komodo Edit 8.0.0
EDIT: I also found this, which indicates there is no other way (and unlikely to be soon).