"that could be used to treat numerous physical and mental ailments" clearly makes panacea ("cure all") as the choice for the second blank.
Now, let us come to the first blank. The following sentence fragment with the clue words highlighted
"the drug will likely be remembered only as a
financial albatross that
bankrupted its developers."
makes it clear that financial resources were expended on the new drug.
The word is
pecuniary.
Note: The word albatross refers to a sea-bird. Figuratively, the expression "albatross around the neck" refers to an annoying hindrance that prevents you from accomplishing a task. Here, financial albatross refers to the finances (or rather the lack of them) acting as an hindrance.
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