07:56 AM EST, 12/24/2024 (MT Newswires) -- Enanta Pharmaceuticals ( ENTA ) said Tuesday that it will appeal a Massachusetts District Court ruling favor of Pfizer ( PFE ) in a patent infringement case related to Pfizer's ( PFE ) COVID-19 antiviral drug, Paxlovid.

The company said the court issued a summary judgment granting Pfizer's ( PFE ) motion that Enanta's patent no. 11,358,953 is invalid, and denied its partial motion for summary judgment on infringement as moot.

"We are disappointed with the court's ruling. We believe strongly in the merits of our case, and, through the appeal process, we will continue to defend our inventions from unlawful infringement," said Jay Luly, chief executive officer of Enanta Pharmaceuticals ( ENTA ).

Enanta shares were more than 4% lower in premarket trading.