So the median pharma industry profit margin is 13.8%. Forget lowering it to fortune 500 average... take it zero. How much lower do drug costs get? Not much. This pill is still going to cost many thousands of dollars.
Any solution will require targeting multiple sources of cost. As you point out elsewhere, R&D is a big cost driver, but profit seems comparable [1]. Moreover one does have to wonder about the various sources of that R&D cost, I'm not an expert but it would seem to me that issues like "evergreening" would inflate development costs unnecessarily.
[1] https://healthpolicy.usc.edu/evidence-base/how-did-the-publi...