Phase III Comparative Study(Open-Label) of MRA for Rheumatoid Arthritis(RA)

Inclusion criteria * Diagnosed as having RA, on the basis of the criteria stipulated by the American Conference on Rheumatism (ACR) in 1987. * With RA that has continued for at least 6 months but less than 5 years, with the date of first appearance being taken as the date of RA diagnosis. * Active RA despite at least one DMARD or immunosuppressant. Active disease is defined as having at least 6 tender and 6 swollen joints among 49 and 46 joints stipulated by the Japanese Rheumatism Foundation's Drug Evaluation Committee and ESR at least 30 mm/hr and CRP not less than 2.0mg/dL. Exclusion criteria * Shown to have class-IV Steinbrocker's functional activity in an evaluation carried out within 4 weeks before administration of the study drug. * Treated with drugs that delay joint destruction (infliximab, etanercept, leflunomide, etc.) within 3 months before administration of the study drug. * The oral corticosteroid dose (prednisolone equivalent of up to 10 mg/day)has not been fixed 2 weeks before administration of the study drug. * Subjected to any of the following within 4 weeks before administration of the study drug: (i) Change in dosage of currently administered DMARDs and/or immunosuppressive agents. (ii) Plasma exchange method. (iii) Surgical treatment (operations, etc.).