US pharma company Eli Lilly has won a federal appeals court decision that protects its cancer drug Alimta from generic versions made by Pfizer and Dr. Reddy’s Laboratories.

The US Court of Appeals for the Federal Circuit upheld a previous district court ruling that Pfizer and Dr. Reddy’s alternative salt forms of the drug would infringe Lilly’s patent.

“Lilly’s extensive research to discover this patent deserves intellectual property protection, which has been confirmed in every challenge in the US to date,” said Michael Harrington, Lilly’s senior vice president and general counsel.

If its patent is ultimately upheld through all remaining challenges, Lilly said Alimta would maintain US exclusivity and prevent the marketing of generic products until it expires in May 2022.

The US District Court for the Southern District of Indiana ruled in favor of Lilly in June 2018 against both Dr. Reddy’s and Hospira, a subsidiary of Pfizer. Both companies, however, appealed that decision. 

This is the latest victory for Lilly, which has fought off several challenges in recent years from generic companies trying to launch alternatives. These companies include, among others, Teva, Barr Laboratories, Neptune Generics and Sandoz.