Evaluating the Effect of Anakinra (r-metHuIL-1ra) on Vaccine AntibodyResponse in Subjects With Rheumatoid Arthritis (RA)

• Anti-tetanus antibody titers at weeks 4 and 8
• Anti-tetanus antibody level changes from baseline to week 4
• Anti-tetanus antibody level changes from week 4 to week 8
• Antibody level of at least 0.1 IU/mL at week 8.
• Safety evaluation of serious adverse events, adverse events and laboratory assessments

The purpose of this study is to estimate the effect of anakinra, 100 mg once daily (QD), on the development of an anti-tetanus antibody response in subjects with RA after vaccination with a tetanus and diphtheria toxoids injection. In addition, this study will evaluate the general safety profile of therapy with anakinra, 100 mg QD, in subjects with RA after vaccination with a tetanus and diphtheria toxoids injection.

Inclusion Criteria: - Diagnosed with RA by American College of Rheumatology (ACR) criteria for greater than or equal to 12 weeks - Active RA with at least 3 swollen joints and 3 tender/painful joints and at least one of the following:

• Morning stiffness greater than or equal to 45 minutes;
• C-reactive protein (CRP) greater than or equal to 1.5 mg/dL;
• Erythrocyte sedimentation rate greater than or equal to 28 mm/hr;
• Stable methotrexate dose of less than or equal to 20 mg/week for 8 weeks prior to randomization;
• Stable doses of nonsteroidal anti-inflammatory drugs (NSAIDs) and oral corticosteroids (less than or equal to 10 mg/day of prednisone or equivalent) for 4 weeks prior to randomization. Exclusion Criteria: - Pregnant or breast-feeding women - Any uncontrolled, clinically significant systemic disease - Has total white cell count less than 3.5 x 10^9/L, a neutrophils count less than 2.0 x 10^9/L, platelet count less than 125 x 10^9/L or hemoglobin (Hgb) less than 8.0 g/dL at screening - Abnormal liver function tests (AST/ALT greater than or equal to 1.5 x the upper limit of normal at screening) - Serum creatinine greater than 1.5 x the upper limit of normal at screening - Subject recall of having tetanus toxoid or diphtheria vaccination less than 10 years prior to randomization - Has never received a primary tetanus vaccination - Any other vaccination within 12 weeks of randomization - Disease-modifying antirheumatic drugs (DMARDs) other than methotrexate - Biologics to treat RA within the previous 8 weeks of screening (e.g., etanercept, infliximab) - Subjects were treated with anakinra within 4 weeks prior to randomization