JAK Inhibitors

Abstract

Summary The JAK/STAT signal transduction pathway, mediated by four Janus kinases (JAK) and seven signal transducer and activator of transcription (STAT) transcription factors, has been implicated in the pathology of autoimmune, allergic, and inflammatory diseases. JAK inhibitors have been increasingly used to treat inflammatory and autoimmune diseases, and this chapter details the research that led the discoveries of JAK inhibitors. Tofacitinib is the first-in-class pan-JAK inhibitor approved for rheumatoid arthritis (RA), psoriatic arthritis, polyarticular course juvenile idiopathic arthritis and ulcerative colitis. In addition to tofacitinib, Pfizer also launched abrocitinib for atopic dermatitis. Baricitinib is approved for RA and atopic dermatitis in Europe. There are several novel JAK inhibitors in advanced development, including ritlecitinib, brepocitinib and ropsacitinib. Peficitinib is a pan-JAK inhibitor approved only in Japan and Korea for the treatment of rheumatoid arthritis.