The main purpose of this study is to see how well a new treatment ramantamig-D works compared to standard treatments that is either DVRd or DRd on progression-free survival (PFS; time until a participant's disease worsens) and 12-month minimal residue disease (MRD)-negative complete response (CR) rate (percentage of participants in whom cancer cells are not detected) in participants with newly diagnosed multiple myeloma (NDMM; an initial stage of blood cancer that forms in a type of white blood cells \[WBCs\] called plasma cells) for whom stem cell transplant is not planned as initial therapy.
Documented diagnosis of multiple myeloma (MM) according to the IMWG diagnostic criteria
Not considered for high-dose chemotherapy with autologous stem cell transplantation (ASCT) due to: i. ineligible due to advanced age; or ii. ineligible due to presence of comorbid condition(s) likely to have a negative impact on tolerability of high-dose chemotherapy with ASCT; or iii. deferral of high-dose chemotherapy with ASCT as initial treatment
Have an eastern cooperative oncology status (ECOG) performance status of 0 to 2
Must sign an informed consent form (ICF)
Myeloma Frailty Score of greater than or equal to (>=) 2 with the exception of participants who have a score of 2 based on age alone
Suspected or known allergies, hypersensitivity, intolerance or other contraindications to any trial intervention or its excipients
Had major surgery (for example, requiring general anesthesia) or had significant traumatic injury within 2 weeks prior to first dose or will not have fully recovered from surgery, or has surgery planned during the time the participant is expected to participate in the trial
Known active or prior CNS involvement or exhibits clinical signs of meningeal involvement of MM