That's because the nature of drug development has been changing significantly over the last 20 years as the well of small molecule blockbuster drugs runs dry. Large pharmaceutical companies are becoming acquisition machines for startups that show promise in the early stages of drug development instead of spending their own capital on research. They do this to increasingly dump more and more of their risk onto venture capitalists and other institutional investors as the cost of drug development climbs slowly upward. Public numbers for pharma R&D budgets rarely reflect the acquisition costs, focusing only on the follow up approval process.

The consumer advertising change did contribute to this though, by allowing pharma companies to concentrate their core competency on acquisition, distribution, and marketing instead of R&D.