Experience with upadacitinib in refractory polyarticular juvenile idiopathic arthritis

Dear Editor, Biologic DMARDs are effective therapies in the management of paediatric patients with JIA. However, patients with polyarticular course JIA may remain refractory to those treatments, requiring new therapeutic options. Upadacitinib (UPA) is a novel, oral selective Janus kinase (JAK) inhibitor that specifically targets JAK1 and inhibits the JAK/Signal Transducers and Activators of Transcription intracellular pathway [1]. To date, it has been approved for the treatment of adults with moderate-to-severe rheumatoid arthritis, spondylarthritis, psoriatic arthritis, atopic dermatitis and moderate-to-severe inflammatory bowel disease to date, as well as adolescents aged 12 years and older with moderate-to-severe atopic dermatitis [2–5]. Clinical experience with UPA and the evaluation of its efficacy in paediatric JIA remain limited, and its use in paediatric cases is still under investigation. In this report, we examined patients with refractory polyarticular JIA who initiated treatment with UPA at a tertiary paediatric rheumatology referral centre. All patients were treated with oral UPA at a dose of 15 mg tablet once daily. Disease activity was assessed by Juvenile Arthritis Disease Activity Score in 27 joints (JADAS27 scores). This study was complied with the principles of the Declaration of Helsinki. Ethical approval was granted by the Ethics Committee of Umraniye Training and Research Hospital (number: B.10.1.TKH.4.34.H.GP.0.01/328). Written informed consent was obtained from the legal guardians of all participants.