Interleukin-6 inhibition and clinical efficacy in rheumatoid arthritis treatment--data from randomized clinical trials.

Interleukin 6 (IL-6), a pleiotropic cytokine with numerous and varied effects on the inflammatory cascade and immune response, appears to be an attractive target for novel immunomodulatory therapy for systemic inflammatory autoimmune diseases. Proof of principal for this approach has come from studies of the anti-IL-6 receptor monoclonal antibody, tocilizumab. Tocilizumab has been assessed in a number of studies in recent years, mainly in patients with rheumatoid arthritis (RA). Data from randomized controlled clinical trials demonstrate the efficacy of tocilizumab in improving the signs and symptoms of RA. In addition, it appears that such inhibition of IL-6 can have positive effects on functional status, an important outcome for RA patients. Finally, data suggest that treatment with this agent may also inhibit the progression of disease as assessed radiographically. Data from studies currently underway will help refine the ultimate use of this novel approach to treatment, and help clinicians optimize therapy using this approach.