Saphnelo (anifrolumab-fnia) is an infusion treatment for adults with moderate to severe systemic lupus erythematosus (SLE) who are also on other lupus medicines. It is a monoclonal antibody that blocks type I interferon (INF-1) receptors, reducing immune system overactivity and inflammation. By limiting excess interferon signals, Saphnelo helps improve SLE symptoms and reduce flares.