Effectiveness and Safety of Rituximab in Patients with Refractory Juvenile Idiopathic Arthritis: A Tertiary Center...

Introduction: Despite the growing spectrum of modern drugs for the treatment of juvenile idiopathic arthritis (JIA), patients with a refractory, progressive course of the disease remain a clinical challenge. B-cell-depleting therapy has demonstrated efficacy in adult rheumatoid arthritis and several pediatric rheumatic diseases, encouraging us to evaluate rituximab (RTX) for children with refractory JIA. Objective: This study aimed to assess the long-term efficacy and safety of rituximab therapy in children with refractory juvenile idiopathic arthritis. Methods: This retrospective, single-center, observational study included 106 patients with JIA who had failed previous therapy. The efficacy and safety of the therapy were evaluated at baseline and at 3, 6, 12, 24, 36, and 48 months post-initial rituximab infusion using the American College of Rheumatology Pediatric Criteria (ACRpedi 30/50/70/90), C. Wallace criteria for inactive disease/remission, and the JADAS71 activity index until patient completion or withdrawal from the study. The primary endpoint was achieving an ACRpedi50 response by 3 months, and the secondary endpoint was achieving inactive disease status according to C. Wallace criteria by 6 months of follow-up. Results: An ACRpedi50 response was achieved in 78/100 (78%) patients by month 3 of rituximab therapy, and inactive disease status was reached in 48/93 (52%) patients by month 6. More than half of the patients demonstrate inactive disease or remission at each observation point. During rituximab therapy, oral glucocorticoids were discontinued in 18/57 (32%) patients, and 28/57 (49%) patients were able to halve their corticosteroid dose (p = 0.03). Rituximab demonstrated an acceptable safety profile, with a total of 351 adverse events (non-serious AEs: 304/351, 87%) and a serious AE rate of 0.8 per 100 patient-years. Conclusions: Rituximab can reduce disease activity and lower the dose of oral glucocorticoids in patients with refractory JIA, serving as a viable therapeutic option with an acceptable safety profile.