Merck is currently spending $2.5 billion per year on clinical trials for Keytruda, one of the most promising treatments for cancer ever. Without the ability to recoup those costs drug development efforts would cease.
Oh jeeze! Not that old nonsense again. How did drug companies recoup their costs before we had thirty year patents? They only got the long patent extension during the Bush years. Before that patents used to expire after 10 years. Patents do not spur innovation. They stifle it. Without patents there would be an explosion in medical inventions, including new drugs. The best way to address development costs is to let the market drive down development costs. Limit the FDA, not competition among drug companies.
BTW most actual research into new drugs is done by academic institutions at public expense. Drug company expenses occur mostly from navigating regulatory hurdles.