Nothing useful came from Axis 'medical experimentation' during the war, as u/commiespaceinvader explains in their answer to the same question. The main answer deals with the Nazi side of things, but Unit 731 is also examined in-thread; you'll want the comments by u/churakaagi and u/Bartweiss, which touch more directly on the matter.

I wrote about the scientific validity and usefulness of Unit 731's experiments, as far as we can tell from unclassified data, here.

In summary most of it was crap but some of it seemed to have been scientifically sound and helpful. Also note that the unit was a biological weapons experiment unit, not a medical one. But at least one or two experiments did seem to have yielded useful results for medical studies.