Regeneron and a South Korea-based rival it had accused of infringing several patents covering the U.S. biotech company's top eye medication Eylea have agreed to a settlement to put an end to the case filed in West Virginia federal court.

U.S. District Judge Thomas S. Kleeh on Tuesday signed off on a stipulation filed by Regeneron and Celltrion Inc. to dismiss Regeneron's case without prejudice, and Regeneron said in a statement that the parties reached a confidential settlement.

Regeneron said in the statement that Celltrion will be allowed to sell a biosimilar of Eylea starting on the final day of 2026.

"Regeneron has invested many years of effort into its design and development of Eylea and remains committed to actively enforcing its intellectual property rights," Regeneron said.

Eylea, which was first approved by the U.S. Food and Drug Administration in 2011, helps treat eye disorders and prevent vision loss and permanent blindness through a genetically engineered fusion protein called aflibercept.

Regeneron sued biosimilar applicant Celltrion in 2023, alleging its biosimilar would infringe a host of patents covering Eylea.

Counsel for Celltrion did not immediately respond to requests for comment Tuesday.

The patents in-suit are U.S. Patent Nos. 9,222,106, 9,254,338, 9,315,281, 9,816,110, 10,130,68, 10,415,055, 10,464,992, 10,669,594, 10,828,345, 10,888,601, 10,927,342, 11,053,280, 11,066,458, 11,084,865, 11,104,715, 11,174,283, 11,253,572, 11,299,532, 11,306,135, 11,312,936, 11,332,771, 11,459,374, 11,472,861, 11,485,770, 11,505,593, 11,525,833, 11,535,663, 11,542,317, 11,548,932, 11,555,176, 11,559,564, 11,707,506, 11,732,024, 11,753,459, 11,769,597, 11,788,102, 11,793,926 and 7,070,959.

Regeneron is represented by Ellen E. Oberwetter, Thomas S. Fletcher, Andrew V. Trask, Teagan J. Gregory, Shaun P. Mahaffy, Kathryn S. Kayali, Arthur J. Argall III, Adam Pan, Rhochelle Krawetz and Jennalee Beazley of Williams & Connolly LLP, Elizabeth Stotland Weiswasser, Christopher M. Pepe and Priyata Y. Patel of Paul Weiss Rifkind Wharton & Garrison LLP, Andrew E. Goldsmith, Jacob E. Hartman, Mary Charlotte Y. Carroll and Sven E. Henningson of Kellogg Hansen Todd Figel & Frederick PLLC and Steven R. Ruby, David R. Pogue and Raymond S. Franks II of Carey Douglas Kessler & Ruby.

Celltrion is represented by Robert Cerwinski, Aviv Zalcenstein, Michael Cottler, Lora Green, David Kim, Brigid Morris, Kyle Musgrove, Cindy Chang and Michael W. Johnson of Gemini Law LLP, Matt Freimuth, Dan Constantinescu and Ocean Lu of Willkie Farr & Gallagher LLP and Michael B. Hissam, Max C. Gottlieb, Andrew C. Robey and Carl W. Shaffer of Hissam Forman Donovan Ritchie PLLC.

The case is Regeneron Pharmaceuticals Inc. v. Celltrion Inc., case number 1:23-cv-00089, in the U.S. District Court for the Northern District of West Virginia.