Janus kinase inhibitors for the treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic inflammatory destructive disorder that affects the joints, muscles, and tendons accompanying various extra-articular manifestations. Traditional disease-modifying anti-rheumatic drugs (DMARDs) represent the basic treatment for rheumatoid arthritis. Over the last 20 years, biologic DMARDs (tumor necrosis factor inhibitors, interleukin-1 inhibitors, interleukin-6 inhibitors, T cell inhibitors, and B cell inhibitors) have been widely used as a novel class of DMARDs that have efficacy and efficiency. Discovery of the underlying pathogenesis of autoimmune disease enables us to develop new target therapies such as a Janus kinase (JAK) inhibitor. Activated JAK is known to activate signal transducers as well as activators of transcription (STAT) signaling. A JAK inhibitor is a type of medication that functions by inhibiting the JAK-STAT signaling pathway. In addition, it is easy to take a JAK inhibitor orally. In Korea, several JAK inhibitors have been approved. This review describes the types of JAK inhibitors, recommended doses, side effects, and updated European Alliance of Associations for Rheumatology guidelines. Clinicians should more often consider JAK inhibitors in the treatment of refractory rheumatoid arthritis in current rheumatology clinics.