Pfizer filed suit against an Indian pharmaceutical company on Friday over its application to market generic versions of Xeljanz XR.
Xeljanz XR is an extended-release version of Pfizer’s blockbuster JAK inhibitor for inflammatory conditions such as rheumatoid arthritis and ulcerative colitis. According to the FDA’s Orange Book, it’s covered by four key patents, three of which expire in 2034.
Pfizer is suing Ajanta Pharma for alleged infringement of the fourth patent, dubbed RE41,783, which expires in December 2025.
While Ajanta has argued that all claims of the ‘783 patent are invalid, Pfizer told a Delaware federal court on Friday that approval of Ajanta’s 11 mg and 22 mg generics would cause “foreseeable harm and injury to Pfizer throughout the United States, including in Delaware.”
Pfizer asked the court to bar Ajanta from marketing its generics before the ‘783 patent expires. It’s the latest in a string of lawsuits that Pfizer has filed over that patent, including another in Delaware earlier this month against Missouri-based SpecGx, which is seeking approval for its 5 mg and 10 mg Xeljanz generics.
Xeljanz generated $1.7 billion in 2023 sales for Pfizer, the company reported.
Ajanta was unavailable for immediate comment.