BIIB057 in Subjects With Rheumatoid Arthritis and Inadequate Response to Disease-Modifying Antirheumatic Drugs

Inclusion Criteria: * Adult onset RA satisfying 2010 Revised ACR Criteria for the Classification of RA with a disease history of at least 6 months * Active RA as defined by: at least 4 swollen joints (based on 28-joint count), at least 4 tender joints (based on 28-joint count), and high-sensitivity CRP (hsCRP) 10mg/L or greater * No prior treatment with biologics * Receiving a DMARD therapy for at least 3 months, using a regimen that has been stable for at least 28 days prior to screening Exclusion Criteria: * History of inflammatory joint disease other than RA * Abnormal chest X-ray consistent with tuberculosis, malignancy, or infection * History of malignancy, carcinoma in situ, or high-grade dysplasia * History of opportunistic infection, infection requiring treatment, serious local infection, recent fever, active herpes zoster or Epstein-Barr virus, or diagnosis or family history of Creutzfeldt-Jakob disease. * Clinically significant cardiac disease * Treatment with prednisone \>10 mg orally daily * Intra-articular steroid injection within 28 days before screening * Clinically significant abnormality in hematology or blood chemistry values at screening