Is tocilizumab an option for the treatment of arthritis?

Background: Some patients with rheumatoid arthritis and systemic-onset juvenile idiopathic arthritis are resistant to inhibitors of interleukin-1 and tumour necrosis factor. Raised levels of interleukin-6 are associated with both these conditions. Tocilizumab is a humanised monoclonal antibody that binds to both forms of interleukin-6 receptor that has recently been used in Phase III trials in rheumatoid arthritis and systemic-onset juvenile idiopathic arthritis. Methods: The study conducted an evaluation of Phase III trials with tocilizumab. Results: In the Tocilizumab Pivotal Trial in Methotrexate Inadequate Responders the primary efficacy end-point was the proportion of subjects with a 20% improvement in their rheumatoid arthritis signs and symptoms according to the American College of Rheumatology criteria and, at 24 weeks, this value was 26% with placebo and was increased to 48 and 59% with tocilizumab at 4 and 8 mg respectively. In the trial of tocilizumab in systemic-onset juvenile idiopathic arthritis, the primary end-point in the open-label lead-in was the proportion of subjects achieving an American College of Rheumatology Pediatric 30 response and 91% of subjects had achieved this at 6 weeks. This response was maintained by the majority of subjects being treated with tocilizumab during a 12-week double-blind trial and 48 weeks of open trial follow-up. Small numbers of subjects developed infections in both studies. Conclusions: Provided long-term safety can be established, tocilizumab will probably become part of the treatment for rheumatoid arthritis and may become a major breakthrough for the treatment of systemic-onset juvenile idiopathic arthritis.