Efficacy and Safety of CDP6038 in Patients With Rheumatoid Arthritis With an Unsuccessful Response to Anti-Tumor Necrosis Factor (Anti-TNF) Therapy

Inclusion Criteria: * Have a diagnosis of rheumatoid arthritis (according to the 1987 ACR classification criteria OR a score of ≥6 as defined by the ACR/European League Against Rheumatism Classification and Diagnostic Criteria for rheumatoid arthritis ) for at least 6 months prior to screening * Must have been treated with MTX 12.5-25 mg/week, for at least 6 weeks prior to screening. Doses of 10 to \< 12.5mg/week are allowed if there is documented intolerance * Have moderately to severely active rheumatoid arthritis disease with at least 6 tender and 6 swollen joints * CRP ≥1.2 times the upper limit of normal (central laboratory) or erythrocyte sedimentation rate of more than 28mm/hour * Intolerant or inadequate response to treatment (ie, TNF blocker failure)≥1 licensed TNF-blocker therapies within 2 years of screening Exclusion Criteria: * Have a diagnosis of any other inflammatory arthritis or secondary, noninflammatory type of arthritis, such as psoriatic arthritis, lupus, gout, or ankylosing spondylitis * Wheelchair bound or bedridden. * Disease modifying antirheumatic drugs (DMARDs) other than MTX. * Treatment with tocilizumab or any other anti-IL-6 investigational therapies at any time. * Treatment with other biologics within 4-24 weeks (depending on the biologic) * History of ongoing, chronic or recurrent infections or recent serious or life-threatening infection * Known concurrent acute or chronic viral hepatitis B or C infection or human immunodeficiency virus (HIV) infection. * Vaccinations (other than injectable influenza or pneumococcal) within 8 weeks prior to screening or plan to receive vaccines during the study * Concurrent or history of malignancy with the exception of nonmelanoma skin cancer successfully treated more than 2 years prior to screening or cervical cancer successfully treated more than 5 years prior to screening. * History of chronic alcohol abuse or drug addiction within the last 1 year or current drug addiction or use of illicit drugs.