Evergreening: A deceptive device in patent rights

Patents are the most important way by which inventors can protect their invention and the income that might derive from innovations developed in return for the full disclosure that enters into public domain after expiration of the patent term. In certain domains, monopolies over patent rights are being extended beyond the patent period, particularly in high-revenue-earning pharmaceutical sectors. This article presents evergreening strategies that are regularly employed by the giant branded pharmaceutical firms as a tactic to bypass existing patent laws and limit generic competition in the marketplace. The article examines the implications of evergreening for different stakeholders, including branded and generic drug companies and consumers. Problems that arise due to evergreening are also discussed. The frequency of such strategies necessitates strong patent interpretations that are protective of the spirit of patent laws. (C) 2010 Elsevier Ltd. All rights reserved.