Randomized, Double-blind, Placebo-controlled, Dose Ranging Study With an Active Comparator to Evaluate the Efficacy and Safety of CDP6038 Administered Subcutaneously for 12 Weeks to Subjects With Rheumatoid Arthritis Having Previously Failed TNF-blocker 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.