Maybe nothing. But we need to take our heads out of the proverbial sand, and try and wrap our brains around the idea that there are alternative ways of monetizing the product of R&D than simply the status quo. Subscription services, “pre-pay” contracts, assurance contracts or specifically dominant assurance contracts, etc.
There is nothing sacrosanct about the current mode of developing, distributing and monetizing pharmaceuticals (or books, or music albums, etc.) . Just because they currently rely on patents/copyrights in no way validates patents/copyrights as the be-all/end-all.
Now, under any of those alternative regimes, I might suggest that once a company has developed the product for which the bounty has been put-up in advance, they have been paid for their time & efforts & investments. Perhaps they make money, perhaps not. I suspect that sometimes they will be profitable, and other times they will not be. But there’s no justification for protecting entrepreneurs from entrepreneurial risk, which is essentially what patents & copyrights do.
Once the product is brought to market, anyone can copy it, and voila, inexpensive drugs.