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.

Etanercept in the treatment of disease-modifying anti-rheumatic drug (DMARD)-refractory polyarticular course juvenile idiopathic arthritis: experience from Japanese clinical trials.

Efficacy, safety, and pharmacokinetics results from 4 studies-3 open-label (OL) and 1 randomized double-blind (DB)-have provided data for approval of etanercept for treatment of disease-modifying anti-rheumatic drug (DMARD)-refractory juvenile idiopathic arthritis (JIA) in Japan. Results from the 3 shorter-term (2 OL and 1 DB) studies are reported here. Subjects (4-17 years) enrolled in the OL studies had active JIA, i.e. ≥5 swollen joints and ≥3 joints with limitation of motion and pain or tenderness. Subjects enrolled in the primary OL study received etanercept 0.4 mg/kg subcutaneously twice weekly; in the lower-dose OL study subjects received etanercept 0.2 mg/kg. Subjects in the primary OL study who completed ≥48 weeks could continue into a 12-week DB dose-down extension study in which subjects received etanercept 0.4 or 0.2 mg/kg twice weekly. The primary endpoint in all 3 studies, i.e. 30% improvement in the American College of Rheumatology criteria for JIA (ACR Pedi 30) at 12 weeks, was achieved by ≥80% of subjects by week 2 and sustained to week 12. Common adverse events reported were injection site reactions, nasopharyngitis, and gastroenteritis. These results provide further evidence that etanercept is effective therapy for DMARD-refractory polyarticular JIA patients.