A federal appeals court has upheld a lower court ruling in favor of Pfizer in a patent dispute with Enanta Pharmaceuticals over the COVID-19 therapy Paxlovid. The Court of Appeals for the Federal Circuit affirmed a summary judgment that U.S. Patent No. 11,358,953, which covers coronavirus protease inhibitors, is invalid. Enanta had filed suit in 2022 seeking damages, alleging Pfizer infringed the patent during Paxlovid's development and commercialization. The U.S. District Court for the District of Massachusetts ruled in December 2024 that the patent was invalid, prompting Enanta's appeal.
Enanta Pharmaceuticals IncAppeals court upheld invalidation of Enanta's patent, eliminating potential damages from Pfizer's Paxlovid sales.
Pfizer IncAppeals court affirmed patent invalidity, removing infringement risk and potential damages for Pfizer.