Inclusion criteria: The main inclusion criteria include, but are not limited to, the following: * Has a clinical diagnosis of rheumatoid arthritis (RA) and meets the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria * Has active disease defined as ≥6 tender joints (based on 68 joints) and ≥6 swollen joints (based on 66 joints) * Is currently being treated with oral or parenteral methotrexate (MTX) * Has a history of one of the following: a) no prior treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), b) bDMARD-inadequate response (IR)/intolerant to a maximum of 2 classes of bDMARDs. Exclusion criteria: The main exclusion criteria include, but are not limited to, the following: * Has any arthritis with onset before age 17 or a current diagnosis of inflammatory joint disease other than RA (such as, but not limited to, a) arthritis psoriatic arthritis, systemic lupus erythematosus, gout, systemic sclerosis, myositis, pseudogout, etc.) or any other condition that, in the investigator's judgment, may interfere with the assessment of RA * Has a history of cancer (except for fully treated non-melanoma skin cancers or cervical carcinoma in situ after complete surgical excision) and has been disease-free for <5 years prior to randomization * Has any active infection * Has known allergies, hypersensitivity, or intolerance to tulisokibart or its excipients