A Study Investigating the Efficacy and Safety of BGB-45035 Versus Placebo in Adults With Moderate to Severe Active Rheumatoid Arthritis

Who May Qualify: - Diagnosed with rheumatoid arthritis (RA) based on American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria for at least 3 months prior to screening - Demonstrated an inadequate response to, or loss of response or intolerance to at least 1 conventional synthetic disease-modifying antirheumatic drug (csDMARD) (Hydroxychloroquine, methotrexate \[MTX\], leflunomide, or sulfasalazine) or 1 biologic disease-modifying antirheumatic drug (bDMARD)/targeted synthetic disease-modifying antirheumatic drug (tsDMARD) treatment - Must be on stable dose of one of the following permitted therapies for ≥ 4 weeks prior to screening and during the study: methotrexate between 7.5 mg to 25 mg/week, hydroxychloroquine up to 400 mg/day, leflunomide up to 20 mg/day, or sulfasalazine between 1000 mg/day to 3000 mg/day Who Should NOT Join This Trial: - Class IV RA based on American College of Rheumatology revised criteria for classification of functional status in rheumatoid arthritis - Patients with a history of cancer in the last 5 years before the Screening Visit, with the exception of adequately treated basal cell or squamous cell carcinoma of the skin - Have failed more than 2 b/tsDMARDs (eg, excluded if have failed 2 bDMARDs and 1 tsDMARD) Always talk to your doctor about whether this trial is right for you.