Main Inclusion Criteria:

          -  Patients with relapsed or primary refractory AML (as defined in WHO criteria) with >5%
             bone marrow blasts

          -  Patients with CD123+ blast cells (verified by flow cytometry)

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

          -  Adequate organ function, including bone marrow, renal, hepatic, pulmonary, and cardiac
             function based on the last assessment performed within screening period

          -  (Dose-escalation) Identified donor and transplant strategy prior to lymphodepletion
             (LD)

          -  Other criteria may apply

        Main Exclusion Criteria:

          -  Patients with APL or CNS Leukemia

          -  Previous investigation gene or cell therapy (including CAR)

          -  ≥ 2 prior allogeneic SCTs

          -  Prior treatment with rituximab or other anti-CD20 therapy within 3 months

          -  Any known active or uncontrolled infection

          -  Other criteria may apply