Inclusion Criteria:

          -  Written informed consent obtained prior to any screening procedures and in accordance
             with federal, local, and institutional guidelines.

          -  Age ≥ 18 years.

          -  Confirmed diagnosis, and evidence of progressive disease or clinical relapse as
             defined by International Myeloma Working Group (IMWG) criteria and following prior
             therapy for MM:

               1. Relapsed or refractory MM requiring current treatment.

               2. Previously failed ≥ 3 prior regimens.

          -  Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 1.

          -  Estimated life expectancy ≥ 4 months.

          -  No other medical, surgical, or psychiatric condition (including active substance
             abuse) that would interfere with compliance to the protocol, as determined by the
             Principal Investigator.

          -  Female subjects of childbearing potential must agree to use dual methods of
             contraception and have a negative serum pregnancy test at Screening, and male subjects
             must use an effective barrier method of contraception if sexually active with a female
             of childbearing potential.

          -  Subjects need a functioning, central venous access in place for the administration of
             agenT-797.

        Exclusion Criteria:

          -  Pregnant or nursing women.

          -  Prior history of invasive malignancy.

          -  Subjects who had an allogeneic stem cell transplantation and are still on
             immunosuppressive medications or corticosteroids above physiological dose.

          -  New York Heart Association Class III or IV heart failure, unstable angina, or a
             history of recent myocardial infarction.

          -  Adverse events from prior anticancer therapy that have not resolved to NCI CTCAE Grade
             ≤ 1.

          -  Receiving any investigational products within 4 weeks or 5 half-lives of cell
             infusion.