Kiniksa Pharmaceuticals International, plc is a biopharmaceutical company that develops and commercializes medical therapies in the United States, the United Kingdom, and internationally. It offers ARCALYST, an interleukin-1alpha and 1beta cytokine trap for the treatment of recurrent pericarditis, a chronic autoinflammatory cardiovascular disease, and cardiac sarcoidosis. The company also develops KPL-387, an investigational fully human immunoglobulin G2 monoclonal antibody in Phase 2/3 clinical trials for recurrent pericarditis, and KPL-116, an Fc-modified immunoglobulin G2 monoclonal antibody in pre-clinical stage. Formerly known as Kiniksa Pharmaceuticals, Ltd., it changed its name to Kiniksa Pharmaceuticals International, plc in June 2024. Incorporated in 2015, it is based in London, the United Kingdom.