A Study of Combination Treatment With MabThera (Rituximab) and RoActemra (Tocilizumab) Versus RoActemra in Patients With Rheumatoid Arthritis With an Incomplete Response to Methotrexate

This 2 part study will investigate the safety, tolerability and efficacy of MabT hera in combination with RoActemra in patients with active rheumatoid arthritis despite a stable dose of methotrexate. In Part 1 of the study, patients will be randomized to receive either MabThera 0.5g iv or placebo on days 1 and 15, follo wed by RoActemra at one of the ascending doses between 2mg/kg and 8mg/kg at week s 4, 8 and 12 (MabThera arm) or 8mg/kg (placebo arm). In Part 2, additional pati ents will be randomized to one of 2 groups to receive MabThera 0.5g on days 1 an d 15 followed by the selected dose (from Part 1)of RoActemra at weeks 4, 8 and 1 2, or placebo on days 1 and 15 followed by RoActemra 8mg/kg at weeks 4,8 and 12. All patients will then be eligible to receive extension treatment withRoActemra every 4 weeks. The anticipated time on study treatment is 12 months, and the tar get sample size is \<100 individuals.