Linda L Hushaw, Ray Sawaqed, Ghaleb Sweis, Jori Reigle, Anjali Gopal, Daniel Brandt, Nadia Sweis, James Curran, Timothy B Niewold, Nadera J SweissUniversity of Chicago, Section of Rheumatology, Chicago, ILL, USAAbstract: Recent advances in our understanding of the role of interleukin (IL)-6 in autoimmunity and in particular rheumatoid arthritis (RA) have brought about important changes in the way we think about autoimmune diseases. Encouraging data from several phase III clinical trials of tocilizumab, a humanized monoclonal antibody against IL-6R, have led to its approval in Europe for the treatment of moderate to severe RA. Data on clinical efficacy, patient-reported outcomes, safety, and cost-effectiveness with the use of tocilizumab in patients with RA will be summarized in this review, with particular emphasis on phase III clinical trials. Furthermore, adverse events associated with the use of tocilizumab will be reviewed. Future clinical trials will evaluate the role of tocilizumab in other autoimmune diseases. The goal of this review is to describe the current understanding of the role of IL-6 in mediating the inflammatory response in RA, as well as the role of tocilizumab in the treatment of RA and the evolving role of this agent in other autoimmune diseases.Keywords: tocilizumab, rheumatoid arthritis, IL-6, methotrexate