This open-label, single arm study will investigate the safety, tolerability and efficacy of tocilizumab monotherapy, or combination therapy with non-biologic disease modifying antirheumatic drugs (DMARDs), in patients with severe active RA. Patients will receive tocilizumab 8mg/kg iv as a 60 minute infusion every 4 weeks for a total of 6 infusions. The anticipated time on study treatment is 3-12 months, and the target sample size is >500 individuals.