Anti-interleukin-6 therapy in rheumatoid arthritis.

Recent advances in research have led to significant progress in unraveling the pathophysiology of rheumatoid arthritis (RA), including the cytokine-mediated signaling process. While therapies targeting one particular cytokine, tumor necrosis factor-alpha (TNF-α), have revolutionized the treatment of RA, other cytokines, including interleukin 6 (IL-6,) have been implicated in the disease process. In this review, we describe the research that ultimately led to large, randomized, controlled trials demonstrating the effectiveness of tocilizumab, a monoclonal antibody directed against the IL-6 receptor, as a potent new therapeutic agent in RA treatment. These data have shown this agent to be effective both in patients failing non-biologic DMARDs and those failing anti-TNF therapy, although the drug is currently approved for use only in the latter situation. Adverse events seen with tocilizumab therapy are also reviewed.