Pfizer Dodges Dismissal of Xeljanz Patent Infringement Lawsuit

Pfizer Inc. avoided early dismissal of its lawsuit against Sinotherapeutics Inc. over alleged infringement of a patent for Xeljanz XR, its blockbuster arthritis drug.

In denying Sinotherapeutics’ motion to dismiss, Judge Gregory B. Williams of the US District Court for the District of Delaware said he wanted the benefit of more evidence before making a determination on its argument that the generic doesn’t infringe Pfizer’s US Patent No. 9,937,181 under the doctrine of equivalents.

Pfizer sued Sinotherapeutics in October 2021 seeking a court order blocking the company’s sales of a generic for Xeljanz XR until its patent expires in 2034.The ...