Merck's Patent on Fosamax Invalidated by Appeals Court

A federal appeals court recently voted to invalidate Merck's patent on its blockbuster osteoporosis treatment Fosamax, clearing the way for generic firms to hone in on the multibillion dollar market for the drug.

In a 2-1 decision, the U.S. Court of Appeals for the Federal Circuit vacated a 2003 decision by a Delaware federal court, which had found Merck's patent on once-weekly Fosamax (alendronate) valid. Generic firm Teva Pharmaceutical appealed that decision to the Federal Circuit.

The appeals court's ruling clears the way for Teva to market a generic version of Fosamax beginning in February 2008. Prior to the appeal court's ruling, Merck's patent on once-weekly Fosamax was set to expire in July 2018.