A Study Comparing Talquetamab Plus Pomalidomide, Talquetamab Plus Teclistamab, and Elotuzumab, Pomalidomide, and Dexamethasone or Pomalidomide, Bortezomib, and Dexamethasone in Participants With Relapsed or Refractory Myeloma Who Have Received an Anti-CD38 Antibody and Lenalidomide

The purpose of this study is to compare the effectiveness of either talquetamab plus pomalidomide (Tal-P) or talquetamab plus teclistamab (Tal-Tec) with elotuzumab, pomalidomide, and dexamethasone (EPd) or pomalidomide, bortezomib, and dexamethasone (PVd).


Eligibility Criteria:
Inclusion Criteria:

* Documented multiple myeloma as defined by the criteria below: (a) multiple myeloma diagnosis according to the international myeloma working group (IMWG) diagnostic criteria (b) measurable disease at screening as assessed by central laboratory, defined by any of the following: (i) serum M-protein level greater than or equal to (\>=) 0.5 gram per deciliter (g/dL); or (ii) urine M-protein level \>= 200 milligram (mg) per 24 hours; or (iii) light chain multiple myeloma without measurable M-protein in the serum or the urine: serum immunoglobulin (Ig) free light chain (FLC) \>= 10 milligrams per deciliter (mg/dL) and abnormal serum Ig kappa lambda FLC ratio
* Relapsed or refractory disease as defined below: a) Relapsed disease is defined as an initial response to prior treatment, followed by confirmed progressive disease (PD) by IMWG criteria greater than (\>) 60 days after cessation of treatment. b) Refractory disease is defined as less than (\<) 25 percent (%) reduction in M-protein or confirmed PD by IMWG criteria during previous treatment or less than or equal to (\<=) 60 days after cessation of treatment
* Documented evidence of PD or failure to achieve a minimal response to the last line of therapy based on investigator's determination of response by IMWG criteria on or after their last regimen
* Have an Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1, or 2 at screening and immediately prior to the start of administration of study treatment
* A participant must agree not to be pregnant, breastfeeding, or planning to become pregnant while enrolled in this study or within 6months after the last dose of study treatment

Exclusion Criteria:

* Contraindications or life-threatening allergies, hypersensitivity, or intolerance to any study drug or its excipients
* Stroke, transient ischemic attack, or seizure within 6 months prior to signing informed consent form (ICF)
* Major surgery or had significant traumatic injury within 2 weeks prior to the start of administration of study treatment, or will not have fully recovered from surgery, or has major surgery planned during the time the participant is expected to be treated in the study or within 2 weeks after administration of the last dose of study treatment
* A maximum cumulative dose of corticosteroids of \>=140 mg of prednisone or equivalent within 14-day period before the first dose of study drug
* Known active central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma. If either is suspected, negative whole brain magnetic resonance imaging (MRI) and lumbar cytology are required