A Mechanism of Action Study to Evaluate the Effects of IL-6 Receptor Blockade With Tocilizumab (TCZ) on Lipids, Arterial Stiffness, and Markers of Atherogenic Risk in Patients With Moderate to Severe Active Rheumatoid Arthritis (RA).

This 2 arm study will investigate the effects of tocilizumab on lipids, arterial stiffness, and markers of atherogenic risk in patients with moderate to severe active rheumatoid arthritis. In Part 1 of the study, patients will be randomized to receive either tocilizumab 8mg/kg intravenously or placebo every 4 weeks, in combination with methotrexate 7.5-25 mg weekly. In Part 2, all patients will receive open-label treatment with tocilizumab plus methotrexate.