Dose-finding of Multiple Dose of BT061 in Patients With Active Rheumatoid Arthritis Incompletely Controlled on Stable Methotrexate (MTX)

Inclusion Criteria: * Patients with active Rheumatoid Arthritis (RA) according to 1987 revised ACR criteria with functional class II-III * Disease activity at screening and baseline (more than 6 swollen joint count; more than 6 tender joint count; elevat. of CRP or ESR) * Duration of RA more than 12 month * History of at least one disease-modifying anti-rheumatic drug (DMARD) with an inadequate response despite more than 3 month of treatment * MTX treatment at least 6 month with a stable dose at least 15mg MTX * Patients could continue at more than daily 7,5mg of prednisone or equivalent stable dose at least 6 weeks prior baseline * Written Informed Consent Exclusion Criteria: * Treatment with traditional DMARDs apart from MTX 12 weeks prior to baseline and DMARD leflunomide 24 weeks * Treatment with any biologics other than TNF-α inhibitors (e.g. abatacept, rituximab, tocilizumab, anakinra) * treatment with any TNF-α inhibitor within 5 elimination half-lives prior baseline and during the study * Clinical non-response to more than one of TNF-α inhibitor exceeding adequate treatment duration