Right now what is happening is that companies are shifting their R&D efforts towards diseases that have relatively low regulatory barriers. The best example is the shift out of diseases like diabetes (treatments are relatively effective, so safety standards are very high) into diseases like cancer (where treatment options are poor and safety standards are relatively low because patients die so quickly).
In the future I think it will be a combination of new technologies that allow drug makers to prove efficacy and safety in a more cost effective way. I also think regulators will soften their hard-line stance on safety (in some areas). The FDA has already started to do this. Instead of saying "that drug isn't proven safe" they are saying "that drug has been proven safe, but it helps a lot so maybe we'll allow the drug company to sell it to a few patients until we get more data".
The current drug patent system isn't the best way to incentivise R&D investment, but all the other options out there seem worse right now. You are correct, however, in saying that the costs associated with drug approval are often external to the company (the FDA). So when you pay $300/month for a new drug, a lot of what you're paying for is an assurance of efficacy and safety (and the gov't agency that assures it's done right).
In the future I think it will be a combination of new technologies that allow drug makers to prove efficacy and safety in a more cost effective way. I also think regulators will soften their hard-line stance on safety (in some areas). The FDA has already started to do this. Instead of saying "that drug isn't proven safe" they are saying "that drug has been proven safe, but it helps a lot so maybe we'll allow the drug company to sell it to a few patients until we get more data".
The current drug patent system isn't the best way to incentivise R&D investment, but all the other options out there seem worse right now. You are correct, however, in saying that the costs associated with drug approval are often external to the company (the FDA). So when you pay $300/month for a new drug, a lot of what you're paying for is an assurance of efficacy and safety (and the gov't agency that assures it's done right).