Inclusion Criteria:

        Participants must satisfy the following criteria to be enrolled in the study:

        1. Participant must understand and voluntarily sign an informed consent form (ICF) prior to
        any study-related assessments/procedures being conducted.

        3. Participant is ≥ 18 years of age at the time of signing the ICF. 4. Relapsed or
        refractory CD33 positive AML at last visit as defined by the World Health Organization
        (WHO) Classification who have failed or who are ineligible for or have refused all
        available therapies for AML which may provide clinical benefit.

        6. Participant has Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0,
        1 or 2.

        7. At least 4 weeks (from first dose) has elapsed from donor lymphocyte infusion without
        conditioning.

        8. Participants must have adequate hematologic, liver, renal, and coagulation function as
        assessed by laboratory tests 9. Females and males must practice true abstinence or agree to
        contraceptive methods throughout the study, and during the safety follow-up period.

        Exclusion Criteria:

        The presence of any of the following will exclude a Participant from enrollment:

          1. Participant is suspected or proven to have acute promyelocytic leukemia (FAB M3) based
             on morphology, immunophenotype, molecular assay, or karyotype.

          2. Participant has received systemic anticancer therapy (including investigational
             therapy) or radiotherapy < 28 days or 5 half-lives, whichever is shorter, prior to the
             start of study treatment. Hydroxyurea is allowed to control peripheral leukemia
             blasts.

          3. Participants with prior autologous hematopoietic stem cell transplant who, in the
             investigator's judgment, have not fully recovered from the effects of the last
             transplant (eg, transplant-related side effects).

          4. Prior allogeneic HSCT with either standard or reduced intensity conditioning ≤ 6
             months prior to dosing.

          5. Participants on systemic immunosuppressive therapy post HSCT at the time of screening,
             or with clinically significant graft-versus-host disease (GVHD). The use of topical
             steroids for ongoing skin or ocular GVHD is permitted.

          6. Participant has persistent, clinically significant non-hematologic toxicities from
             prior therapies which have not recovered to < Grade 2.

          7. Participant has or is suspected of having central nervous system (CNS) leukemia.
             Evaluation of cerebrospinal fluid is only required if CNS involvement by leukemia is
             suspected during screening.

          8. History of concurrent second cancers requiring active, ongoing systemic treatment.

          9. Participant is known seropositive or active infection with human immunodeficiency
             virus (HIV), or active infection with hepatitis B virus or hepatitis C virus.

         10. Impaired cardiac function or clinically significant cardiac diseases, as defined in
             the protocol .

         11. Participant is a pregnant or lactating female.