From what I understand, the R&D for many drugs are researched at public institutions using public funding. Many drug manufacturers hop on to the gravy train at some point and may fund 50% of the research so that they can claim exclusive rights to said drug. Tax payers are still funding a good chunk of those costs. Additionally drug makers have been milking products for decades. Look at the Epi Pen. It was made in the 1970's and approved in 1987 by the FDA. Yet somehow the price goes up every year. They have more then made their costs back 10 fold. This appears to be the norm for drug manufacturers. Inevitably us consumer pay for both the cost of the drug with an x increase in price per year and pay for a good chunk of the research. The drug companies have many cash cows that they didn't have to invest too much in, compared to the returns they get out of it.
Maybe the drug manufacturers can use more of their own money to fund more research instead of giving multi millions dollar bonuses to executives.