Inclusion Criteria:  ≥18 years of age at the time of informed consent form (ICF) signature Adult patients with relapsed and refractory multiple myeloma who have received at least 3 prior lines of therapy including an IMiD (e.g., lenalidomide or pomalidomide), a proteasome inhibitor (e.g., bortezomib, carfilzomib), and an approved anti-CD38 antibody (e.g., daratumumab, isatuximab), and have documented evidence of disease progression (IMWG criteria) Must be refractory to the last treatment regimen (defined as progressive disease on or within 60 days measured from last dose of last regimen). Measurable disease at enrollment as defined by the protocol Eastern Cooperative Oncology Group (ECOG) performance status that is either 0 or 1 at screening Must have a leukapheresis material of non-mobilized cells accepted for manufacturing  Exclusion Criteria:  Prior administration of a genetically modified cellular product including prior BCMA CAR-T therapy. Participants who have received prior BCMA -directed bi-speciific antibodies or anti-BCMA antibody drug conjugate. Prior allogenic stem cell transplantation (SCT) at any time or autologous SCT within 3 months prior to signing informed consent Plasma cell (PC) leukemia and other plasmacytoid disorders, other than MM POEMS syndrome Active central nervous system (CNS) involvement by malignancy Patients with active neurological auto immune or inflammatory disorders  Other protocol-defined Inclusion/Exclusion may apply.