Tofacitinib Treatment of Refractory Systemic Juvenile Idiopathic Arthritis.

Systemic juvenile idiopathic arthritis (sJIA) is an aggressive form of childhood arthritis accompanied by persistent systemic inflammation. Patients with sJIA often exhibit poor response to conventional disease-modifying antirheumatic drugs, and chronic glucocorticoid use is associated with significant adverse effects. Although biologics used to target interleukin 1 and interleukin 6 are efficacious, the long-term commitment to frequent injections or infusions remains a challenge in young children. Janus-activated kinase (JAK) inhibitors block the signaling of numerous proinflammatory cytokines and are now used clinically for the treatment of rheumatoid arthritis in adults. Whether this new class of medication is effective for sJIA has not been reported. Here, we describe the case of a 13-year-old girl with recalcitrant sJIA characterized by polyarticular arthritis, fever, lymphadenopathy, and serological features of inflammation. She showed minimal response to nonsteroidal antiinflammatory drugs, glucocorticoids, conventional disease-modifying antirheumatic drugs, and etanercept. She also developed osteoporosis and vertebral compression fracture as the result of chronic glucocorticoid therapy. Oral therapy with the JAK inhibitor tofacitinib was initiated, and the patient experienced steady improvement of both arthritis and systemic features. Complete remission was achieved after 3 months, and no evidence of disease activity or adverse effects was seen through 6 months of follow-up. Our experience reveals the effectiveness of JAK inhibition in a case of refractory sJIA. Tofacitinib is an intriguing oral alternative to the available biologics for children with sJIA, and its efficacy and safety should be further assessed by clinical trial.