Extension Study of Tocilizumab Long Term Treatment of Moderate to Severe Rheumatoid Arthritis Patients

Inclusion Criteria: * Patients who had completed at least 5 out of the 7 visits scheduled for weeks 2, 4, 8, 12, 16, 20 and 24 in the tocilizumab Phase IIIb study(MRA230TW). * Patients assigned in the Phase IIIb study(MRA230TW), who had received scheduled dose for at least 16 weeks but still failed to achieve adequate treatment response characterized by ACR20 Exclusion Criteria: * Patients who have received a major surgery including joint surgery 8 weeks prior to the screening or are scheduled to be operated within 6 months after the enrolment. * Patients with rheumatoid autoimmune disease other than RA, including but not limited to SLE(system lupus erythematosus), or significant systemic involvement secondary to RA. * Patients who belong to the Class IV of the ACR classification criteria for functional status of RA. (ACR Amended Criteria for the Classification of Functional Capacity in Rheumatoid Arthritis; Class IV: Largely or wholly incapacitated with patient bedridden or confined to wheel chair, permitting little or no self-care). * Patients with a history of hypersensitivity to human, humanized or murine monoclonal antibodies or patients with contraindication for them. * Patients who currently have or have a history of recurrence of bacterial, viral,fungal, or mycobacterial infections or other infectious diseases; tuberculosis(TB),atypical mycobacterial disease, clinically significant granulomatous disease on chest radiograph, hepatitis B, hepatitis C, or herpes zoster and etc. However, a patient with hand \& foot fungal infections can participate.