Safety and Efficacy of Donor T-lymphocytes Depleted ex Vivo of Host Alloreactive T-cells (ATIR) in Patients With a Hematologic Malignancy Who Received a Hematopoietic Stem Cell Transplantation From a Haploidentical Donor

Inclusion Criteria: * Any of the following hematologic malignancies: a) Acute myeloid leukemia (AML) in first remission with high-risk features or in second or higher remission b) Acute lymphoblastic leukemia (ALL) in first remission with high-risk features or in second or higher remission c) Myelodysplastic syndrome (MDS): transfusion-dependent, or intermediate or higher Revised International Prognostic Scoring System (IPSS-R) risk group * Eligible for haploidentical stem cell transplantation according to the investigator Exclusion Criteria: * Availability of a suitable matched related or unrelated donor following a donor search * In second or higher remission with the previous remission having lasted less than 6 months * Diffusing capacity for carbon monoxide (DLCO) \< 50% predicted * Left ventricular ejection fraction \< 50% (evaluated by echocardiogram or multiple gated acquisition \[MUGA\]) * Aspartate aminotransferase (AST) \> 2.5 x upper limit of normal (ULN)(CTCAE grade 2) * Bilirubin \> 1.5 x ULN (CTCAE grade 2) * Creatinine clearance \< 50 mL/min (calculated or measured) * Positive test for human immunodeficiency virus (HIV) * Positive pregnancy test (women of childbearing age only) * Prior allogeneic stem cell transplantation using stem cells from a matched sibling donor, a matched unrelated donor, a haploidentical donor, or a cord blood donor * Prior autologous stem cell transplantation * Stay at intensive care unit for more than 2 months in the preceding 12 months * Estimated probability of surviving less than 3 months * Known allergy to any of the components of ATIR (e.g., dimethyl sulfoxide) * Any other condition which, in the opinion of the investigator, makes the patient ineligible for the study Donor inclusion criteria * Haploidentical family donor with 2 to 3 mismatches at the human leukocyte antigen (HLA)-A, -B and/or -DR loci of the unshared haplotype * Male or female, age ≥ 16 and ≤ 75 years * Eligible for donation according to the transplantation center Donor exclusion criteria * Positive viral test for HIV-1, HIV-2, hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum, human T-lymphotropic virus (HTLV)-1\*, HTLV-2\*, or West Nile virus (WNV)\* (if tested) (\* at Canadian centers only) * Positive pregnancy test or nursing (women of childbearing age only)