Viagra

Viagra Lawsuits

by Rene Ciria-Cruz (2010)

Since Viagra’s patent expired in March 2012, Pfizer faced the prospect of saying good-bye to more than $1 billion a year in exclusive sales of its impotence drug. But the pharmaceutical giant isn’t about to give up its market share without a fight. Last March, Pfizer filed a federal suit to prevent Teva Pharmaceuticals from selling generic Viagra until 2019. The Israeli company, which specializes in making and distributing generic drugs, has received Food and Drug Agency (FDA) approval to start selling its copycat version of the pill as soon as Pfizer’s main patent expires (Pfizer Inc. v. Teva Pharmaceuticals USA, Inc., No. 10-128 (E.D. Va. filed Mar. 24, 2010).

According to the lawsuit, Teva’s planned release of generic Viagra would infringe one or more claims of Pfizer’s patent (No. 6,469,012), which covers Viagra’s use for erectile dysfunction. Pfizer claims that the FDA’s “Orange Book” lists that patent’s expiration date as October 22, 2019, not 2012 as Teva contends.

The Orange Book is the FDA’s roster of Approved Drug Products with Therapeutic Equivalence Evaluations. Generic drugs are identical or acceptably bioequivalent to the branded counterpart in dose, strength, route of administration, safety, efficacy, and intended use. The FDA’s use of the word identical is very much a legal, not a literal, interpretation.

The U.S. Patent and Trademark Office (USPTO) allows separate patents for a drug’s composition and for its method of use in treating a particular medical problem. But experts say such method-of-use protection isn’t as strong as an original composition-of-matter patent; hence, Teva’s challenge.