The current system of FDA approval seems to make few happy. Some argue FDA approves drugs too slowly; others too quickly. Many agree that FDA—and the health system generally—should gather information after drugs are approved to learn how well they work and how safe they are. This is hard to do. FDA has its own surveillance systems, but those systems face substantial limitations in practical use. Drug companies can also conduct their own studies, but have little incentive to do so, and often fail to fulfil study commitments made to FDA. Proposals to improve this dynamic often suggest gathering more information after approval in various ways and incorporating that information into FDA’s decision-making process, making the information/access tradeoff more nuanced than a sharp binary at approval. The drug approval regime has already begun to move in this direction.
Price, W. Nicholson, II. "Drug Approval in a Learning Health System." Minn. L. Rev. 102, no. 6 (2018): 2413-62.