Inclusion Criteria (condensed):

          -  Multiple myeloma that is double-refractory to a proteasome inhibitor (PI) and an
             immunomodulatory drug (IMiD) after at least 2 prior lines of therapy OR have failed at
             least 3 prior lines of therapy

          -  Measurable disease activity as indicated by serum or urine M-protein, serum free light
             chain, biopsy-proven plasmacytoma, >5% bone marrow plasma cells.

          -  Adequate vital organ function as indicated by ANC (>1000/uL), platelet count
             (>50,000/uL), hemoglobin (>8 g/dL), serum ALT and AST (each <3.0 x upper limit of
             normal), total bilirubin (<2 mg/dL), creatinine clearance (>30 mL/min), and cardiac
             ejection fraction (>45%)

        Exclusion Criteria (condensed):

        NOTE: Prior anti-BCMA or CAR-T therapy is NOT exclusionary

          -  Active plasma cell leukemia

          -  Pregnant or lactating

          -  Active, uncontrolled infection

          -  Active and severe auto-immune disease

          -  Active arrhythmia, or obstructive or restrictive pulmonary disease

          -  Central nervous system disease