Inclusion Criteria: - Participants aged ≥18 with Newly Diagnosed Multiple Myeloma (NDMM) who has received induction therapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT), without subsequent consolidation or maintenance. EXCEPTION: Participant received ≤ 7 days of lenalidomide (LEN) maintenance therapy and the investigator documents that there is no impact to the overall benefit/risk assessment due to the temporary interruption of LEN. - Participant must have received 4 to 6 cycles of induction therapy, which must contain at a minimum an immunomodulatory drugs (IMiD) and a proteasome inhibitor (PI) (with or without anti-CD38 monoclonal antibody) and must have had a single ASCT 80 to 120 days prior to consent. Note: Participant must not have confirmed progression since commencing induction. - Participant must have documented response of PR or VGPR at time of consent. - Participant must have Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1 (participants with ECOG 2 due to pain because of underlying myeloma-associated bone lesions are eligible per investigator's discretion). - Participant must have recovered to ≤ Grade 1 for any nonhematologic toxicities due to prior treatments, excluding alopecia and Grade 2 neuropathy. Exclusion Criteria: - Participant with known central nervous system involvement with myeloma. - Participant has non-secretory MM. - Participant has systemic and uncontrolled fungal, bacterial, viral, or other infection. - Participant has history of primary immunodeficiency. - Participant has previous history of an allogeneic hematopoietic stem cell transplantation or treatment with any gene therapy-based therapeutic for cancer or investigational cellular therapy for cancer or B-cell maturation antigen targeted therapy.