A Phase I/II Study Evaluating the Safety and the Efficacy of SMART101 Injection to Accelerate Immune Reconstitution After T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric and Adult Patients With Hematological Malignancies

Inclusion Criteria: Group A (adults): 1. Adult patients affected by: * Acute leukemia (AML, ALL) defined as: * Acute Myeloid Leukemia (AML): * High risk AML in CR1; any adverse genetic abnormality, secondary or therapy related AML excluding good risk genetic abnormalities * Chemo-refractory relapse (MRD+) * ≥ CR2 * Acute Lymphoblastic Leukemia (ALL): * Chemo-refractory relapse (MRD+) * High risk ALL in CR1; Philadelphia (like) or any poor risk feature * ≥ CR2 * Acute leukemia of ambiguous lineage: * ≥ CR1 with a minimal residual disease (MRD) \<5% (flow cytometry, molecular and/or cytogenetics accepted) * Myelodysplastic Syndrome (MDS) with least one of the following: * Revised International Prognostic Scoring System risk score of intermediate or higher at the time of transplant evaluation. * Life-threatening cytopenia. * Karyotype or genomic changes that indicate high risk for progression to acute myelogenous leukemia, including abnormalities of chromosome 7 or 3, mutations of TP53, or complex or monosomal karyotype. * Therapy related disease or disease evolving from other malignant processes. 2. Patient eligible for a T-depleted allogeneic HSCT 3. Age ≥ 18y and clinical condition compatible with allogeneic stem cell transplantation 4. Karnofsky index ≥ 70% prior to conditioning regimen 5. Patients with normal organ function prior to conditioning regimen Group B (pediatrics): 1. Pediatric patients affected by acute leukemia defined as: * Acute Myeloid Leukemia (AML): * High risk AML in CR1; any adverse genetic abnormality, secondary or therapy related AML excluding good risk genetic abnormalities, * Chemo-refractory relapse (MRD+) * ≥ CR2 * Acute Lymphoblastic Leukemia (ALL): * Chemo-refractory relapse (MRD+) * High risk ALL in CR1; Philadelphia (like) or any poor risk feature * ≥ CR2 * Acute leukemia of ambiguous lineage: * ≥ CR1 with a minimal residual disease (MRD) \<5% (flow cytometry, molecular and/or cytogenetics accepted) 2. Patient eligible for a T-depleted allogeneic HSCT 3. Age \< 18y at the time of inclusion 4. Absence of a matched sibling donor (MSD) 5. Lansky ≥ 70% / Karnofsky performance status ≥ 70% prior to conditioning regimen 6. Patients with normal organ function prior to conditioning regimen Exclusion Criteria: Groups A and B: 1. Use of an HLA matched Cord Blood (8/8 allele matched) or haploidentical donor 2. Prior therapy with allogeneic stem cell transplantation 3. Treatment with another cellular therapy within one month before inclusion