Enanta Pharmaceuticals (ENTA) said late Tuesday it has filed a notice of appeal with the US Court of Appeals for the Federal Circuit in its patent infringement lawsuit against Pfizer (PFE), seeking damages related to the manufacture, use, and sale of COVID-19 antiviral, Paxlovid.

The company said the appeal follows a ruling by the Federal Circuit affirming last December's judgment by a US District Court, which found Enanta's claims invalid.