My understanding of drug dev is that finding stuff that might work is not the challenge, but verifying how well and with what side effects is.

That verification might start in some simulated computer environment but needs to move into physical wet lab, animal testing and then human testing.

So medicine is quite a bit different than code/math where you have a perfectly verifiable problem space that can be iterated within by AI infinitely.

A good example might be Alzheimer's where the brain plaque was thought to be a cause, lots of research on various ways to prevent or reduce the plaque and then it turns out that doesn't matter at all, or is more a byproduct than a cause of the disease.

edit: In general we have many diseases we don't understand and drugs that work via mechanisms we don't understand. So it seems very hard to have a computer simulation in which AI can test medicine. The simulator work seems like the actual problem to solve, not the invention portion.