1. Documented diagnosis of MM with relapsed or refractory disease to at least two prior
             MM treatment regimens which should include exposure to IMiD and PIs either alone or in
             combination.

          2. Presence of measurable disease as per International Myeloma Working Group (IMWG)
             Response Criteria

          3. Eastern Cooperative Oncology Group (ECOG) below or equal 2

          4. Adequate hematologic, renal, hepatic, pulmonary, and cardiac function

        Exclusion Criteria:

          1. History or presence of clinically relevant central nervous system (CNS) pathology.

          2. Autologous stem cell transplant within 12 weeks of registration or an allogeneic stem
             cell transplant within 6 months of starting study treatment.

          3. Any investigational agent within 3 weeks prior to the initiation of the
             non-myeloablative preconditioning chemotherapy).

          4. Prior systemic therapy for MM within 14 days prior to the initiation of the
             non-myeloablative preconditioning chemotherapy.

          5. Prior treatment with any BCMA-targeted therapy and which has not achieved at least a
             partial response.