Pfizer and GlaxoSmithKline have agreed to end a lawsuit over alleged patent infringement involving their competing respiratory syncytial virus (RSV) vaccines, according to a filing made in Delaware federal court.The lawsuit alleged that Pfizer’s RSV vaccine, Abrysvo, violated GSK’s patent rights in its competing RSV vaccine Arexvy.The companies said they would dismiss the case “with prejudice,” preventing it from being refiled. Spokespeople for the companies did not immediately respond to Reuters’ requests for comment and more information, including whether the case was settled.Read also: Pfizer gets European Commission marketing nod for RSV vaccine Abrysvo to protect infants, older adultsGSK, 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 it 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 said in the lawsuit that Pfizer began working on its RSV program around 2013, at least seven years after GSK began developing its shot.Read also: Pfizer Abrysvo gets European Commission nod for RSV Lower Respiratory Tract Disease in adults aged 18-59 yearsPfizer 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.Read also: Pfizer wins bid to invalidate 2 GSK patents relating to RSV vaccine