This single arm, open-label study will assess the safety and efficacy with regar d to reduction of signs and symptoms of treatment with tocilizumab in combinatio n with methotrexate, in patients with moderate to severe active rheumatoid arthr itis. Patients will receive tocilizumab 8mg/kg iv, every 4 weeks and methotrexat e 10-25mg weekly. The anticipated time on study treatment is 3-12 months, and th e target sample size is <500 individuals.