JAK Inhibitors for Rheumatoid

Although biologic therapies have changed expectation and outcomes for rheumatoid arthritis, the optimal therapy for this disease has yet to be determined. There are still a significant number of patients who do not respond satisfactorily to currently available therapies. The Janus kinase inhibitors represent a new class of therapies for rheumatoid arthritis. Tofacitinib is the first drug in this class to have demonstrated efficacy and a reasonable safety profile, and other examples, such as baracitinib, are in the late stages of development. Thesedrugs workuniquely by inhibiting intracellular pathways thought to be important in the pathogenesis of rheumatoid arthritis. They are available as oral agents, which is also different than the currently available biologics. Tofacitinib has been carefully evaluated in multiple phase 3 clinical trials, and although safety concerns cannot fully be answereduntilthedrugisstudiedoverlongerperiodsoftime,thedatatodatesuggestthat this drug—and perhaps other JAK inhibitors—may represent an important addition to the therapeutic armamentarium. Further study and experience will better define when these drugs should be used and in which patients.