Targeting interleukin-6 in pediatric rheumatic diseases

PURPOSE OF REVIEW: To describe the most recent data regarding the role of interleukin-6 (IL-6) in immune and inflammatory responses, the mode of action and safety information on tocilizumab, the only available IL-6 inhibitor, and discuss recent results on the therapeutic inhibition of IL-6 in pediatric rheumatic diseases. RECENT FINDINGS: New data on the effects of IL-6 on T and B cells have been published. Clinical trials with tocilizumab in adults, particularly with rheumatoid arthritis, provide new data on mechanism of action and a reasonably wide safety database. A withdrawal design trial showed marked efficacy in systemic juvenile idiopathic arthritis (s-JIA). Open label studies or anecdotal reports suggest possible efficacy also in other JIA subtypes, as well as other rheumatic diseases. SUMMARY: Targeting IL-6 activities is an effective approach in the treatment of chronic inflammatory diseases. The long-term benefit and safety of tocilizumab have to be defined in long-term extension studies. The risk/benefit ratio appears to be particularly favorable in s-JIA. With the increasing number of biologics becoming available, future efforts should be directed to the definition of biomarkers that will identify responders to each novel biologic, allowing a personalized approach.