<b>Safety, Efficacy, and Tolerability of Tofacitinib in Children and Adolescents With Juvenile Idiopathic Arthritis in Pakistan</b>

Background: Juvenile idiopathic arthritis is a chronic inflammatory disorder of childhood that often requires treatment escalation beyond conventional synthetic disease-modifying antirheumatic drugs, particularly in patients with persistent or refractory disease. In resource-constrained settings, biologic therapy may be limited by cost, access, and treatment logistics, making orally administered targeted therapies such as tofacitinib clinically relevant. Objective: To evaluate the safety, efficacy, and tolerability of tofacitinib in children and adolescents with juvenile idiopathic arthritis treated in a real-world Pakistani cohort. Methods: This prospective study included 47 patients aged 2–18 years with juvenile idiopathic arthritis managed at two rheumatology centers in Lahore, Pakistan, between January 2024 and February 2025. Data were extracted from routine clinical records and electronic databases. Baseline demographic and clinical characteristics, Physician Visual Analog Scale scores, adverse events, infections, and reasons for treatment discontinuation were recorded. Changes in disease activity were analyzed using paired statistical testing, and adverse-event frequencies were summarized with confidence intervals and exposure-adjusted rates. Results: The mean age was 14.15 ± 3.88 years, and polyarticular juvenile idiopathic arthritis was the most frequent subtype. Mean Physician Visual Analog Scale score decreased from 7.15 ± 0.91 at baseline to 2.96 ± 1.60 at follow-up, with a mean reduction of 4.19 ± 1.51 points (p<0.0001). Improvement was observed in 95.7% of patients. Adverse events occurred in 6.4%, no infections or serious adverse events were recorded, and treatment discontinuation occurred in 6.4%. Conclusion: Tofacitinib was associated with substantial short-term improvement in physician-assessed disease activity and acceptable early tolerability in this Pakistani juvenile idiopathic arthritis cohort. Larger multicenter studies with longer follow-up and standardized outcome measures are needed to confirm long-term safety and effectiveness.