This is an open-label, extension, Phase III study to evaluate the long-term safety and efficacy of MRA in patients with RA who participated in Study MRA213JP.

Inclusion criteria

• Either MRA or placebo was administered at least 3 times in the preceding study, and there were confirmed to be no problems with respect to safety.
• In the case of Patients whose participation in the current study was judged to be inappropriate because of problems in the preceding study with respect to safety, these Patients must have been in the methotrexate dose group in the preceding study.

Exclusion criteria

• Administered drugs such as infliximab, etanercept, and leflunomide within 12 weeks before administration of the study drug
• Evaluated as belonging to Steinbrocker's class IV within 4 weeks before administration of the study drug
• Have not been registered by 3 months after the full code-breaking of the preceding study
• Were administered plasma exchange therapy between initiation of the preceding study and the initial administration in the current study
• Treated surgically (except for local surgery) within 4 weeks before administration of the study drug