Long-Term Safety and Effectiveness of Etanercept in Children With Selected Categories of Juvenile Idiopathic Arthritis

Objective. This study was undertaken to evaluate the long-term safety and effectiveness of etanercept alone or in combination with methotrexate (MTX) in children with selected categories of juvenile idiopathic arthritis (JIA). Methods. Patients ages 2-18 years with rheumatoid factor (RF)-positive or RF-negative polyarthritis, systemic JIA, or extended oligoarthritis were eligible for the study. Patients received MTX alone (>= 10 mg/m(2)/ week [similar to 0.3 mg/kg/week], maximum dosage 1 mg/kg/week), etanercept alone (0.8 mg/kg/week, maximum dose 50 mg), or etanercept plus MTX for 3 years in an open-label, nonrandomized study. Safety was assessed by measuring rates of adverse events, and effectiveness was assessed using the physician's global assessment of disease activity and the pediatric total joint assessment. Results. A total of 197, 103, and 294 patients were enrolled in the MTX, etanercept, and etanercept plus MTX groups, respectively. Exposure-adjusted rates of adverse events were similar among the 3 treatment groups (18.3, 18.7, and 21.6 per 100 patient-years in the MTX, etanercept, and etanercept plus MTX groups, respectively). Respective rates per 100 patient-years of serious adverse events (4.6, 7.1, and 6.0) and medically important infections (1.3, 1.8, and 2.1) were also similar among the 3 treatment groups. Scores for physician's global assessment and total active joints improved from baseline, and improvement was maintained for the duration of the study. Conclusion. These data confirm the findings of other long-term studies and suggest that etanercept or etanercept plus MTX has an acceptable safety and effectiveness profile in children with selected categories of JIA. Improvement was maintained for 3 years in those continuing to receive medication.