Evergreening
Strategies drug manufacturers use to extend patent protection beyond the original expiration — including new formulations, delivery methods, or minor modifications.
How It Works
Evergreening tactics include: (1) filing "continuation" patents on narrow aspects of the drug's use; (2) switching from immediate-release to extended-release formulations; (3) combining two existing drugs into a single pill; (4) developing new routes of administration (switching from a pill to a patch); and (5) patenting specific polymorphs or crystal structures. Critics call these "product hopping" strategies that delay generic competition without meaningful therapeutic benefit. The FTC has challenged several evergreening practices as anti-competitive. The Orange Book lists all patents manufacturers claim cover their drugs — these patents are what generic manufacturers must challenge or wait out.
Related Terms
- Patent Expiration — The date when a drug's patent protection ends, allowing generic or biosimilar manufacturers to produce competing versions.
- Patent Cliff — A sharp drop in a drug's revenue when its patent expires and generic competitors enter the market, often cutting prices by 80% or more.
- Exclusivity Period — A period of market protection granted by the FDA (separate from patents) during which generic competitors cannot be approved — even if no patent exists.
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About This Definition
This definition is part of the DrugPrice Drug Pricing Glossary — 34 terms explaining how prescription drug pricing works in the United States. All definitions are written in plain language for patients, caregivers, journalists, and healthcare professionals.