Tofacitinib: A Review in Rheumatoid Arthritis.
Tofacitinib (Xeljanz®) is a potent, selective JAK inhibitor that preferentially inhibits Janus kinase (JAK) 1 and JAK3. In the EU, oral tofacitinib 5 mg twice daily is indicated for the treatment of moderate to severe active rheumatoid arthritis (RA) in adult patients who have responded inadequately to, or who are intolerant of, one or more DMARDs. Several clinical studies of ≤ 24 months' duration showed that tofacitinib monotherapy (as first- or second-line treatment) and combination therapy with a conventional synthetic DMARD (csDMARD; as second- or third-line treatment) was effective in reducing signs and symptoms of disease and improving health-related quality of life (HR-QOL), with benefits sustained during long-term therapy (≤ 96 months). Tofacitinib monotherapy inhibited progression of structural damage in methotrexate-naïve patients during ≤ 24 months' treatment, with beneficial effects also seen in patients receiving tofacitinib plus methotrexate as second-line therapy for 12 months. Tofacitinib was generally well tolerated during ≤ 114 months' treatment, with most adverse events of mild or moderate severity. The tolerability profile of tofacitinib was generally similar to that of biological DMARDs (bDMARDs), with infections and infestations the most common adverse events (AEs) in tofacitinib recipients. However, the incidence of herpes zoster (HZ) was higher with tofacitinib than in the general RA population, although infections were clinically manageable. When added to background methotrexate, tofacitinib was noninferior to adalimumab in terms of efficacy, and both combination therapies had generally similar tolerability profiles. Although additional comparative studies are needed to more definitively position tofacitinib relative to bDMARDs and other targeted synthetic DMARDs, current evidence indicates that oral tofacitinib is a useful option for the treatment of patients with RA.