This is a randomized, double-blind, parallel-group, global, multicenter study of subcutaneous (SC) sirukumab monotherapy compared with adalimumab monotherapy in subjects with active rheumatoid arthritis. Approximately 510 subjects will be randomly assigned in a 1:1:1 ratio to receive treatment with adalimumab 40 mg SC every 2 weeks, sirukumab 100 mg SC every 2 weeks, or 50 mg SC every 4 weeks, with approximately 170 subjects per treatment group. At Week 16, subjects in all treatment groups who have < 20% improvement from baseline in both swollen and tender joint counts will qualify for early escape. The expected duration of the study is 68 weeks. This includes 52 weeks of treatment with study agent and 16 weeks of safety follow-up after the last study agent administration. The study will end when the last subject completes the last scheduled visit (Week 68 visit or completes the 16 week safety follow-up, whichever is later). Subject safety will be monitored through the end of the study.