MajesTEC-9: This study is evaluating the effectiveness of immunotherapy, compared to targeted therapy and steroids, in people with relapsed or refractory multiple myeloma who have had prior therapyA Phase 3 Randomized Study Comparing Teclistamab Monotherapy Versus Pomalidomide, Bortezomib, Dexamethasone (PVd) or Carfilzomib, Dexamethasone (Kd) in Participants With Relapsed or Refractory Multiple Myeloma Who Have Received 1 to 3 Prior Lines of Therapy, Including an Anti-CD38 Monoclonal Antibody and Lenalidomide

Exclusion

• Received any prior B cell maturation antigen (BCMA)-directed therapy
• A participant is not eligible to receive PVd as control therapy if any of the following are present: (1) Received prior pomalidomide therapy, (2) Does not meet criteria for bortezomib retreatment (3) Contraindications or life-threatening allergies, hypersensitivity, or intolerance to pomalidomide or bortezomib, (4) Grade 1 peripheral neuropathy with pain or Grade greater than or equal to (>=) 2 peripheral neuropathy as defined by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version 5.0, (5) Received a strong cytochrome P (CYP) 3A4 inducer within 5 half-lives prior to randomization; A participant is not eligible to receive Kd as control therapy if any of the following are present:(1) Received prior carfilzomib therapy, (2) Uncontrolled hypertension, defined as an average systolic blood pressure greater than (>)159 millimeters of mercury (mmHg) or diastolic blood pressure >99 mmHg despite optimal treatment (3) Grade 2 peripheral neuropathy with pain or Grade >=3 peripheral neuropathy as defined by NCI-CTCAE Version 5.0, (4) Contraindications or life-threatening allergies, hypersensitivity, or intolerance to carfilzomib (intolerance defined as prior therapy discontinued due to any adverse event [AE] related to carfilzomib)
• Central nervous system (CNS) involvement or clinical signs of meningeal involvement of multiple myeloma.
• Received a live, attenuated vaccine within 4 weeks before randomization
• Plasma cell leukemia at the time of screening, Waldenstrom's macroglobulinemia, polyneuropathy, organomegaly, endocrinopathy, M-protein (POEMS) syndrome and skin changes, or primary amyloid light chain amyloidosis
• Received a maximum cumulative dose of corticosteroids of >=140 mg of prednisone or equivalent within 14 days prior to randomization