Systemic-onset juvenile idiopathic arthritis (sJIA) is a chronic childhood disease associated with many complications.1–5 Treatments comprise non-steroidal anti-inflammatory drugs, corticosteroids, disease-modifying antirheumatic drugs and biologics,6–9 including tocilizumab, an interleukin-6 receptor monoclonal antibody.10

Results of a randomised, placebo-controlled, phase III trial of tocilizumab in sJIA patients at eight Japanese hospitals, as well as the first 48 weeks of an open-label extension, have been published.3 Protocols and amendments for this extension phase were approved by the Japanese Ministry of Health, Labor and Welfare and the institutional review board at each centre. Of 56 patients initially enrolled, six withdrew during the open-label, lead-in phase (anti-tocilizumab antibodies, three; anaphylactoid reaction, one; gastrointestinal haemorrhage, one; non-efficacy, one). During the double-blind phase, one patient from each treatment arm withdrew because of adverse events (AEs) but re-entered the open-label extension after the resolution of AEs. In total, 50 patients responding to tocilizumab and needing further treatment entered the open-label extension; two patients subsequently withdrew within the first year because of AEs. Herein, the long-term efficacy and safety of treatment through 144 weeks are presented. …