Long-term efficacy and safety of etanercept in children with polyarticular-course juvenile rheumatoid arthritis: Interim results from an ongoing multicenter, open-label, extended-treatment trial

Objective. To evaluate the long-term efficacy and safety of etanercept in children with juvenile rheumatoid arthritis (JRA) participating in an ongoing multicenter, open-label, extended-treatment trial. All patients had been participants in an initial randomized efficacy and safety trial of etanercept. Methods. Etanercept was administered at a dosage of 0.4 mg/kg (maximum 25 mg) subcutaneously twice each week. Safety and efficacy evaluations were performed every 3-4 months. The JRA 30% definition of improvement (DOI) was defined. as improvement of ≥30% in at least 3 of 6 response variables used to assess disease activity, with no more than 1 variable worsening by more than 30%. Results. At the time of analysis, 48 of the 58 patients (83%) were still enrolled in the study; 43 of them (74%) had completed 2 years of treatment. Of these 43 patients, 81% met the JRA 30% DOI, 79% met the JRA 50% DOI, and 67% met the JRA 70% DOI. Ten children started low-dose methotrexate after year 1. Of the 32 children taking prednisone, the dosage was decreased to <5 mg/day in 26 (81%). Two children had serious infections (varicella with aseptic meningitis in one and complicated sepsis in the other). In general, adverse events were of the types seen in a general pediatric patient population. Conclusion. Children with severe, longstanding, methotrexate-resistant polyarticular JRA demonstrated sustained clinical improvement with >2 years of continuous etanercept treatment. Etanercept was generally well-tolerated. There were no increases in the rates of adverse events over time. However, children taking etanercept should be monitored closely for infections.