This two part, multi-center, open-label, single-arm study will evaluate the efficacy and safety of RoActemra/Actemra as a monotherapy or in combination with non-biologic disease modifying antirheumatic drugs (DMARDs) in patients with moderate to severe rheumatoid arthritis who have an inadequate response or are intolerant to non-biologic DMARDs or biologic therapy. 162 mg RoActemra/Actemra will be administered once a week by subcutaneous injection for up to 76 weeks.