Forces influencing generic drug development in the United States: a narrative review

BACKGROUND: The United States (U.S.) Food and Drug Administration, as protectors of public health, encourages generic drug development and use so that patients can access affordable medications. The FDA, however, has limited mechanisms to encourage generic drug manufacturing. MAIN RESULTS: Generic drug manufacturers make decisions regarding development of products based on expected profitability, influenced by market forces, features of the reference listed drug, and manufacturing capabilities, as well as regulatory restrictions. Barriers to the development of generic drugs include the challenge of demonstrating bioequivalence of some products, particularly those that are considered to be complex generics. CONCLUSIONS: We present here a focused review describing the influences on generic manufacturers who are prioritizing drugs for generic development. We also review proposed strategies that regulators may use to incentivize generic drug development.