Abstract: Tofacitinib is an oral Janus kinase (JAK) inhibitor, which can block JAK/STAT signal transduction pathway and reduce the production and release of a variety of cytokines. It has been approved by the US Food and Drug Administration and the European Medicines Agency for the treatment of active adult patients with psoriatic arthritis (PsA) who are inadequate or intolerant to methotrexate or other antirheumatic drugs (DMARDs). PsA is a chronic immune-mediated systemic inflammatory disease. After the majority of cytokines involved in the pathogenesis of PsA bind to the receptor, JAK binds to the intracellular part of the recipient and activates the intracellular signal pathway mediated by signal transducer and transcriptional activator (STAT) protein, resulting in pro-inflammatory cytokine gene transcription. It has been proved that tofacitinib is safe and effective in the treatment of PsA, showing the similar efficacy compared with biologic agents. The research progress of tofacitinib in the treatment of PsA is reviewed in this article.

Key words: tofacitinib, psoriatic arthritis, JAK inhibitor