Document Type
Article
Publication Date
2025
Abstract
For more than two decades, policymakers have been told that pharmaceutical innovators companies engage in a practice that is called, disparagingly, “evergreening.” The basic idea is that companies introduce new versions of their drugs that have later expiring patents or regulatory exclusivity. This way, the claim goes, the companies effectively block generic entry for years or decades longer than Congress intended and than is socially desirable. Initially these claims were supported by poorly researched anecdotes. In the last decade, some scholars and advocacy organizations have published papers that purport to provide empirical support for the “evergreening” accusation. But these empirical studies do not bridge the gap from proof of innovation to proof that generic drugs are blocked from the market. Indeed, studies consistently show generic drug approval and launch 12 to 14 years after the FDA first approves a new molecular entity, even while innovators continue to innovate with their molecules. Recent reports claiming that innovators engage in “evergreening” with biologics similarly miss the mark. Misleadingly irrelevant data, combined with inflammatory rhetoric, may therefore be leading policymakers and the public to support policy proposals that have no basis in the real world. And because these proposals aim to curtail or even punish continuing innovation, they will have real-world consequences for patients. This chapter represents an effort to set the record straight.
Recommended Citation
Erika Lietzan,
Evergreening's Empirical ChasmBringing Medicines to Life: How Intellectual Property Enables Innovation in the Life Sciences (eds. Jonathan M. Barnett and Bowman Heiden, Cambridge University Press, forthcoming 2026)
(2025).
Available at: https://scholarship.law.missouri.edu/facpubs/1358