Pfizer Keeps Win in Patent Lawsuit Aimed at Paxlovid Antiviral

Enanta Pharmaceuticals Inc. failed to convince the Federal Circuit to revive a patent it claims Pfizer Inc. infringed with its blockbuster Covid-19 antiviral drug Paxlovid.

Enanta’s US Patent No. 11,358,953 was properly canceled and Enanta’s related infringement suit was properly nixed ahead of a trial, the US Court of Appeals for the Federal Circuit said.

An earlier, related patent application which Enanta filed in July 2020 listed the chemical structure for which it sought protection as NHC(O)—C₂-C₁₂-alkyl as opposed to NHC(O)—C₁-C₁₂-alkyl. That latter compound was listed in a July 2021 ...