If you want thin margins, maybe government research wing can take its findings from idea to market (imagine waiting on a cure and that’s your only hope?)
But you can’t force a private company to operate on low margins by way of capping prices, you’ll kill them. You can’t taje away their ability to control their risks (cash flow). Drug R&D already has a huge failure rate and now the company can only take a 5% profit on the slight chance they’ve found something effective?