JAK inhibitor: tofacitinib, a new disease modifying anti-rheumatic drug

Abstract

Treatment of rheumatoid arthritis (RA) with biologic agents targeting inflammatory cytokines and cell surface molecules such as tumor necrosis factor and Interleukin-6 is generally more efficacious than traditional disease-modifying antirheumatic drugs when combined with MTX. However, not only do ∼30% of patients poorly respond to treatment but also parenteral mode of administration and expense are issues to be solved. Recently, a kinase inhibitor targeting Janus kinases (JAKs), has shown high efficacy in active RA in clinical trials. Among several JAK inhibitors in clinical trials for RA, tofacitinib is a step ahead for use in clinical practice. Kinase inhibitors are orally available, which is a major advantage over biologic agents, in addition to being less expensive. This review describes recent advance in JAK inhibitors for RA and its possible mechanism of action.