A Study to Assess the Effect of Tocilizumab + DMARD Therapy on Signs and Symptoms in Patients With Moderate to Severe Active Rheumatoid Arthritis

This 2 arm study will compare the safety and efficacy, with regard to reduction of signs and symptoms, of tocilizumab versus placebo in combination with traditional Disease-Modifying Anti-Rheumatic Drug (DMARD) therapy in patients with moderate to severe active rheumatoid arthritis (RA) who have had an inadequate response to current DMARD therapy. Patients will be randomized to receive tocilizumab 8mg/kg iv or placebo iv every 4 weeks, in conjunction with stable DMARD therapy. The anticipated time on study treatment is 3-12 months, and the target sample size is 500+ individuals.