Inclusion Criteria:

        Signed informed consent

        Meeting institutional criteria to undergo allogenic HSCT

        Age 18-70 y/o (12-70 y/o in US only)

        Patients with AML or MDS as defined below:

        AML Patients Patients with intermediate to adverse AML as defined by ELN (Dohner, 2017).

          -  AML in first complete remission (CR1) with high-risk features defined as > 1 cycle of
             induction therapy required to achieve remission OR preceding MDS or myeloproliferative
             disease

          -  AML in CR1 with intermediate-risk features

          -  AML in second or subsequent complete response

          -  AML with myelodysplasia-related changes (AML-MRC)

          -  Therapy related AML in first or subsequent complete remission

          -  De novo AML in second or subsequent complete remission

        MDS Patients

          -  High or very-high risk MDS by IPSS-R classification

          -  Intermediate risk or higher MDS patients who failed a hypomethylating agent

        Lack of suitable conventional donor (i.e. HLA 10/10 related or unrelated donor)

        At least a 5/10 genotypic identical haplotype match

        The donor and recipient must be identical, at least one allele of each of the following
        genetic loci: HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1

        Patients with adequate organ function

        Eastern Cooperative Oncology Group (ECOG) performance status: 0-2

        Exclusion Criteria:

          -  HLA 10/10 allele matched (HLA-A,-B,-C,-DRBl, and DQB1) related donor or unrelated
             donor

          -  Autologous hematopoietic stem cell transplant ≤ 3 months before enrollment

          -  Prior allogeneic transplantation

          -  Active CNS involvement by malignant cells (less than 2 months from the conditioning)

          -  Current uncontrolled clinically active bacterial, viral or fungal infection

          -  Positive HIV serology or viral RNA

          -  Pregnancy (positive serum or urine βHCG test) or breast-feeding

          -  Fertile men or women unwilling to use effective forms of birth control or abstinence
             for a year after transplantation

          -  Radiographic, histologic, or known history of cirrhosis

          -  Overlapping MDS and myeloproliferative neoplasms (MPN) disease

          -  Patients with acute promyelocytic leukemia (APL)

          -  Known hypersensitivity to dimethyl sulfoxide (DMSO)