Here is an extensive list of generic drug names.
At first glance (just skimming through the “A” page), I see plenty of examples and plenty of counter-examples.
(Not to mention various counter-examples of OP’s thesis that generic names are pronounceable at least in English.)
ETA: OP specifically mentions aducanamab – In that other thread, I recall some mention that this is simply bamanacuda spelled backward. So that’s just named after a dangerous game fish.