Long-term safety and efficacy of etanercept in children with polyarticular-course juvenile rheumatoid arthritis

Objective. Previous studies showed that etanercept treatment in patients with polyarticular-course juvenile rheumatoid arthritis (JRA) provided rapid clinical improvement that was sustained for up to 2 years. The goal of our study was to provide data on safety and efficacy after 4 years of etanercept treatment in patients with JRA. Methods. Patients with active polyarticular-course JRA who participated in an efficacy study continued etanercept treatment in an open-label extension. Safety was assessed by measuring rates of serious adverse events (SAEs) and serious infections. Efficacy was assessed using the American College of Rheumatology (ACR) Pediatric 30 criteria for improvement and standard measures of disease activity. (The ACR Pediatric 30 criteria are defined as improvement of ≥30% in at least 3 of 6 core response variables used to assess disease activity, with no more than 1 variable worsening by ≥30%.) Results. Of the 69 patients who enrolled in the original efficacy study, 58 patients (84%) enrolled in the extension, 34 patients received etanercept treatment for ≥4 years, and 32 of these received complete efficacy assessments. The rate of SAEs was 0.13 per patient-year, and the rate of serious infections was 0.04 per patient-year, in a total etanercept exposure of 225 patient-years. Eighty-two percent of patients who received corticosteroids at any time during the extension were able to decrease their dosage to ≤5 mg/day prednisone equivalent. Of the 32 patients with complete efficacy data who received etanercept for ≥4 years, 94% achieved an ACR Pediatric 30 response and 78% achieved an ACR Pediatric 70 response at the last study visit. Conclusion. Etanercept offers an acceptable safety profile in children with polyarticular-course JRA and provides significant improvement in disease manifestations that are sustained for ≥4 years.