Efficacy and safety of tocilizumab in Chinese patients with systemic juvenile idiopathic arthritis: a multicentre phase IV trial

Given the limited tocilizumab (TCZ) treatment data for systemic juvenile idiopathic arthritis (sJIA) in China, we evaluated the long-term efficacy and safety of TCZ in Chinese patients with sJIA.

In this multicentre, interventional Phase IV study, patients with sJIA and inadequate clinical response to non-steroidal anti-inflammatory drugs/corticosteroids received TCZ infusions every 2 weeks based on body weight (< 30 kg, 12 mg/kg; ≥ 30 kg, 8 mg/kg), over a 52-week open-label period and an 8-week safety follow-up period. The primary endpoint was the proportion of patients with a JIA American College of Rheumatology (ACR) 30 response and absence of fever at Week 12.

Sixty-two patients were enrolled and treated (12-mg/kg group, 34; 8-mg/kg group, 28). At Week 12, 87.1% (95% confidence interval 78.8%–95.4%) of patients had JIA ACR 30 response and absence of fever; Week 52 results were similar. The proportion of JIA ACR 30/50/70/90 responders rapidly increased at Week 12, up to Week 52. High-sensitivity C-reactive protein (hsCRP) levels decreased within 4 weeks; 44/58 patients (75.9%) with elevated baseline hsCRP recovered at Week 52. Childhood Health Assessment Questionnaire pain scores, disability index scores, and mean corticosteroid dose decreased over time. Height standard deviation score changes at Week 52 indicated catch-up growth. Most adverse events (AEs) were mild (serious AE incidence, 17.7%). No deaths or macrophage activation syndrome occurred.

This is the first multicentre trial to report the efficacy and safety of TCZ in Chinese patients with sJIA at 52 weeks. No new safety concerns were found.