Pfizer has said that a federal court in the Middle District of North Carolina has upheld the company's U.S. patent covering amlodipine besylate, the active ingredient in Norvasc, the world's most-prescribed branded medicine for treating hypertension.
The patent had been challenged by the generic manufacturer, Synthon Pharmaceuticals.
Judge James A. Beaty ruled that the patent (U.S. Patent No. 4,879,303) covering amlodipine besylate is valid and infringed by the generic manufacturer's product. The decision, which is subject to appeal, prohibits Synthon from launching a generic version of amlodipine until September 2007.
"The court has affirmed the validity of our Norvasc patent. We will continue to defend against any patent challenges that seek to undermine the incentives established for bringing innovative medicines to patients," said Allen Waxman, Pfizer's general counsel. In January 2006, the same Norvasc patent was held valid and infringed by Apotex in a decision by the Northern District Court of Illinois.