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

Inclusion Criteria: * patients at least 18 years of age with moderate to severe active RA for at least 6 months; * inadequate response to current anti-rheumatic therapies, including 1 or more traditional DMARDs; * stable DMARD therapy for at least 8 weeks before entering study; * patients of reproductive potential must be using reliable methods of contraception. Exclusion Criteria: * major surgery (including joint surgery) within 8 weeks before entering study, or planned surgery within 6 months after entering study; * patients who have previously failed treatment with an anti-tumor necrosis factor agent; * women who are pregnant or breast-feeding.