A Study Comparing Teclistamab Monotherapy Versus Pomalidomide, Bortezomib, Dexamethasone (PVd) or Carfilzomib, Dexamethasone (Kd) in Participants With Relapsed or Refractory Multiple Myeloma

Inclusion Criteria:

• Documented diagnosis of multiple myeloma as defined by the criteria below: (a)Multiple myeloma diagnosis according to International Myeloma Working Group (IMWG) diagnostic criteria (b) Measurable disease at screening as defined by any ofthe following: (1) Serum M-protein level greater than or equal to (>=)0.5 grams perdeciliter (g/dL) (central laboratory); or (2) Urine M-protein level >=200 milligrams (mg)/24 hours (central laboratory); or (3) Serum immunoglobulin free light chain >=10 milligrams per deciliter (mg/dL) (central laboratory) and abnormal serumimmunoglobulin kappa lambda free light chain ratio

• Received 1 to 3 prior lines of antimyeloma therapy including a minimum of 2consecutive cycles of an anti- cluster of differentiation 38 (CD38) monoclonalantibody at the approved dosing regimen in any prior line and 2 consecutive cyclesof lenalidomide in any prior line

• Documented evidence of progressive disease or failure to achieve a response to lastline of therapy based on investigator's determination of response by Internationalmyeloma working group (IMWG) criteria

• Have an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2

• A female participant must agree not to be pregnant, breast-feeding, or plan tobecome pregnant while enrolled in this study or within 6 months after the last doseof study treatment

• Must be willing and able to adhere to the lifestyle restrictions specified in thisprotocol

Exclusion Criteria:

• Received any prior B cell maturation antigen (BCMA)-directed therapy

• A participant is not eligible to receive PVd as control therapy if any of thefollowing are present: (1) Received prior pomalidomide therapy, (2) Does not meetcriteria for bortezomib retreatment (3) Contraindications or life-threateningallergies, hypersensitivity, or intolerance to pomalidomide or bortezomib, (4) Grade 1 peripheral neuropathy with pain or Grade greater than or equal to (>=) 2peripheral neuropathy as defined by National Cancer Institute Common TerminologyCriteria for Adverse Events (NCI-CTCAE) Version 5.0, (5) Received a strongcytochrome P (CYP) 3A4 inducer within 5 half-lives prior to randomization; Aparticipant is not eligible to receive Kd as control therapy if any of the followingare present:(1) Received prior carfilzomib therapy, (2) Uncontrolled hypertension,defined as an average systolic blood pressure greater than (>)159 millimeters ofmercury (mmHg) or diastolic blood pressure >99 mmHg despite optimal treatment (3)Grade 2 peripheral neuropathy with pain or Grade >=3 peripheral neuropathy asdefined by NCI-CTCAE Version 5.0, (4) Contraindications or life-threateningallergies, hypersensitivity, or intolerance to carfilzomib (intolerance defined asprior therapy discontinued due to any adverse event [AE] related to carfilzomib)

• Received a maximum cumulative dose of corticosteroids of >=140 mg of prednisone orequivalent within 14 days prior to randomization

• Received a live, attenuated vaccine within 4 weeks before randomization

• Central nervous system (CNS) involvement or clinical signs of meningeal involvementof multiple myeloma

• Plasma cell leukemia at the time of screening, Waldenstrom's macroglobulinemia,polyneuropathy, organomegaly, endocrinopathy, M-protein (POEMS) syndrome and skinchanges, or primary amyloid light chain amyloidosis