A Study Comparing Talquetamab in Combination With Daratumumab or in Combination With Daratumumab and Pomalidomide Versus Daratumumab in Combination With Pomalidomide and Dexamethasone in Participants With Multiple Myeloma That Returns After Treatment or is Resistant to Treatment

Prior treatment

• Received prior pomalidomide therapy
• A maximum cumulative dose of corticosteroids to \>=140 milligrams (mg) of prednisone or equivalent within 14-day period before the first dose of study drug

Other illness

• Contraindications or life-threatening allergies, hypersensitivity, or intolerance to study drug excipients
• Disease is considered refractory to an anti-cluster of differentiation 38 (CD38) monoclonal antibody as defined per IMWG consensus guidelines (progression during treatment or within 60 days of completing therapy with an anti-CD38 monoclonal antibody)
• Plasma cell leukemia (per IMWG criteria) at the time of screening, Waldenström's macroglobulinemia, polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS syndrome), or primary amyloid light chain amyloidosis

Other

• 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

• Documented multiple myeloma as defined: a) Multiple myeloma diagnosis according to the International Myeloma Working Group (IMWG) diagnostic criteria and b) Measurable disease at screening as defined by any of the following: i) Serum M-protein level greater than or equal to (\>=) 0.5 grams per deciliter (g/dL) (central laboratory); ii) Urine M-protein level \>= 200 milligram (mg) per 24 hours (central laboratory); iii) Light chain multiple myeloma without measurable M-protein in the serum or the urine: serum immunoglobulin free light chain \>= 10 milligram per deciliter (mg/dL) (central laboratory), and abnormal serum immunoglobulin kappa lambda free light chain ratio
• Relapsed or refractory disease as defined by: i) Relapsed disease is defined as an initial response to prior treatment, followed by confirmed progressive disease by IMWG criteria greater than (\>) 60 days after cessation of treatment; ii) Refractory disease is defined as less than (\<) 25 percent (%) reduction in monoclonal paraprotein (M-protein) or confirmed progressive disease by IMWG criteria during previous treatment or less than or equal to (\<=) 60 days after cessation of treatment
• Received at least 1 prior line of antimyeloma therapy including a proteasome inhibitor (PI) and lenalidomide. Participants who have received only 1 prior line of antimyeloma therapy must be considered lenalidomide-refractory (that is, have demonstrated progressive disease by IMWG criteria on or within 60 days of completion of lenalidomide-containing regimen). Participants who have received \>=2 prior lines of antimyeloma therapy must be considered lenalidomide exposed
• Documented evidence of progressive disease based on investigator's determination of response by the 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