I think you could start with the patents. Patent royalties provide perverse incentives to market the drugs, to prescribe drugs for problems that the drugs were never approved for use on, and to simply acquire market share.
Take away the patents and then see how happy they are to bombard doctors with their message. Take away the patents and see how happy they are to pay for national prime time advertising. Take away the patents and suddenly people will see a need for drug research that is paid for upfront, or a manner of research that is modeled after the way research is done for neglected diseases.
I'd say a big part of the opioid crisis is the patents.
Nowhere are the terrible results of intellectual property more prevalent than in the pharmaceutical industry.