British pharmaceutical giant GlaxoSmithKline (GSK) and rival Pfizer have agreed to end a lawsuit that alleged Pfizer’s respiratory syncytial virus (RSV) vaccine, Abrysvo, violated GSK’s patent rights in its competing RSV shot, Arexvy, according to a Thursday filing in Delaware federal court.

GSK and Pfizer stated in the filing that they would dismiss the case with prejudice, meaning it cannot be refiled. Spokespeople for the companies did not immediately respond to requests for comment and more information, including whether the case was settled.

GSK, Pfizer, and Moderna have developed RSV shots approved by the U.S. Food and Drug Administration, with GSK’s Arexvy responsible for the majority of U.S. RSV vaccine sales. The respiratory disease typically causes cold-like symptoms but is also a leading cause of pneumonia in toddlers and older adults.

GSK sued Pfizer in 2023, arguing that the New York-based company’s vaccine infringed GSK patents related to antigen technology. GSK claimed in the lawsuit that Pfizer began working on its RSV program around 2013, at least seven years after GSK began developing its shot. Pfizer denied the allegations and argued GSK’s patents were invalid. It convinced a London court to invalidate related UK patents owned by GSK in a separate case last year.

GSK has also sued Pfizer for patent infringement in the U.S. over technology in Pfizer’s blockbuster COVID-19 vaccine, Comirnaty. That case is still ongoing.