Efficacy and safety of tofacitinib as monotherapy in Japanese patients with active rheumatoid arthritis: a 12-week, randomized, phase 2 study
The oral Janus kinase (JAK) inhibitor, Tofacitinib, preferentially inhibits signalling by heterodimeric receptors associated with JAK3 and/or JAK1, blocking signalling for several cytokines. The purpose of this study was to evaluate the efficacy of tofacitinib monotherapy versus placebo in Japanese patients with inadequate response to disease-modifying anti-rheumatic drugs (DMARDs). Data on response rates – ACR20/50/70, DAS28-4(ESR), and HAQ-DI – laboratory parameters and adverse events were collected from 318 patients.
Findings from this study show dose related efficacy for all tofacitinib doses versus placebo. Treatment emergent adverse events were similar between treatment groups, with a trend towards higher incidence with increasing tofacitinib dose. A long-term extension study including patients from the present study has recently been completed to evaluate longer-term safety and efficacy measures.