A Partially Blinded, Randomized, Multi-Center, Phase IV Trial to Evaluate Mechanism of Action of Anti-TNF Agents in Rheumatoid Arthritis

Inclusion Criteria:

- Diagnosis of RA. More information on this criterion can be found in the protocol.

- Disease duration as defined from the onset of symptoms of at least 3 months prior to
study entry

- Active RA with DAS28 > 4.4, clinically requiring the addition of anti-TNF therapy

- Stable dose of MTX between 7.5 mg and 25 mg weekly for at least 8 weeks prior to
study entry

- Able and willing to self-administer subcutaneous injections or have available
qualified person(s) or caregiver to administer subcutaneous injections

- For females, agree to use accepted methods of contraception during the duration of
the study and for 150 days after study completion. More information on this criterion
can be found in the protocol.

Exclusion Criteria:

- Positive PPD (> 5 mm induration regardless of prior Bacille Calmette Guerin [BCG]
vaccine administration) without evidence of ongoing treatment for at least 30 days or
completed treatment

- History of positive PPD or chest x-ray findings indicative of prior TB infection,
without documentation of either treatment for TB infection or chemoprophylaxis for TB
exposure

- Prednisone dose > 10 mg/day (or equivalent dose of another corticosteroid) within 30
days prior to study entry

- Definitive diagnosis of another autoimmune disease that may require immunosuppression
for treatment. More information on this criterion can be found in the protocol.

- Concomitant use of DMARDSs. More information on this criterion can be found in the
protocol.

- Any immunosuppressive therapy other than MTX, NSAIDs, or corticosteroids. More
information on this criterion can be found in the protocol.

- Current or previous use of any biologic agent

- Presence of open leg ulcers

- Chronic or persistent infection that might be worsened by immunosuppressive
treatment. More information on this criterion can be found in the protocol.

- Active infection or severe infections requiring hospitalization or treatment with IV
antibiotics, IV antivirals, or IV antifungals within 30 days prior to study entry

- Received oral antibiotics, antivirals, or antifungals within 14 days prior to study
entry

- Certain abnormal laboratory values. More information on this criterion can be found
in the protocol.

- Any medical condition that, in the opinion of the investigator, would interfere with
the study

- History of malignancy other than treated localized carcinoma in situ of the cervix or
adequately treated non-metastatic squamous or basal cell skin carcinoma within 10
years prior to study entry

- Any Investigational agent within the earlier of 4 weeks or 5 half-lives prior to
study entry

- History of drug or alcohol abuse within 6 months prior to study entry

- Known allergy or hypersensitivity to study products

- Inability or unwillingness to follow the protocol

- Any condition or treatment that, in the opinion of the investigator, places the
participant at an unacceptable risk

- Pregnant or breastfeeding