For more information regarding Bristol-Myers Squibb Clinical Trial participation, please visit www.BMSStudyConnect.com Inclusion Criteria: - Early rheumatoid arthritis (RA), defined as symptoms of RA that started ≤ 12 months prior to screening and satisfied the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2010 criteria for the classification of RA at some point during the 12-month period - Naïve to any targeted (biologic or nonbiologic) disease-modifying antirheumatic drugs (DMARDs), conventional synthetic DMARDs other than methotrexate (MTX), or investigational therapies for RA - Treated with MTX for at least 12 weeks, with a stable dose of oral or parenteral MTX for at least 4 weeks prior to randomization - Anti-cyclic citrullinated peptide-2 (Anti-CCP-2) test that is > 3× the upper limit of normal and are positive for rheumatoid factor (RF) according to central lab testing during screening - At least a Disease Activity Score 28-joint count calculated using C-reactive protein (DAS28-CRP) ≥ 3.2 at screening - At least 3 tender and at least 3 swollen joints at screening and at randomization Exclusion Criteria: - Women who are breastfeeding - Autoimmune disease other than RA (e.g., psoriasis, systemic lupus erythematosus [SLE], vasculitis, seronegative spondyloarthritis, inflammatory bowel disease, Sjogren's syndrome) or currently active fibromyalgia - History of or current inflammatory joint disease other than RA (e.g., psoriatic arthritis, gout, reactive arthritis, Lyme disease) - At risk for tuberculosis - Recent acute infection - History of chronic or recurrent bacterial infection (e.g., chronic pyelonephritis, osteomyelitis, bronchiectasis) - History of infection of a joint prosthesis or artificial joint - History of systemic fungal infections (such as histoplasmosis, blastomycosis, or coccidiomycosis) - History of primary immunodeficiency - Current clinical findings or a history of a demyelinating disorder - 5 or more joints cannot be assessed for tenderness or swelling Other protocol-defined inclusion/exclusion criteria apply