Safety and efficacy of long-term etanercept in the treatment of methotrexate-refractory polyarticular-course juvenile idiopathic arthritis in Japan.

Objectives: Previous short-term trials found etanercept (0.2 or 0.4 mg/kg) to be effective and well tolerated in Japanese children with juvenile idiopathic arthritis (JIA) who were intolerant/resistant to methotrexate. The aim of this study was to evaluate the long-term safety and efficacy of etanercept in Japanese children with JIA.

Methods: Patients (4-19 years) who received etanercept in one of three short-term studies continued onto this long-term open-label study.

Results: Of the 32 patients enrolled, 18 (56.3%) completed 192 weeks of the study and 14 (43.8%) were discontinued; 7 (21.9%) for patient refusal, 2 (6.3%) for adverse events (AEs), and 5 (15.6%) for lack of efficacy. All patients reported AEs; 31 (96.9%) reported infections and 6 (18.8%) reported serious AEs. Main efficacy assessments included change from baseline in the American College of Rheumatology Pediatric core components, including mean improvements from baseline in the physician global assessment (90.7%), patient/guardian global assessments (54.1%), Childhood Health Assessment Questionnaire (84.6%), and median improvements in C-reactive protein levels (92.7%). No unexpected safety results were reported, and early efficacy responses were sustained in the long term.

Conclusions: This study provides further evidence that etanercept is an effective therapeutic option for Japanese children with polyarticular-course JIA.