Personalized Targeted Preparative Regimen Before T-depleted Allogeneic HSCT in Children With Chemoresistent Acute Leukemias

Inclusion Criteria: 1. Ability to give informed consent (for patients \> 14 years old). For subjects \< 18 years old their legal guardian must give informed consent 2. Disease stage * Acute myeloid leukemia (AML), relapsed or refractory, failure to achieve hematologic remission after at least to courses of intensive chemotherapy, including at least one course with high-dose AraC and fludarabine * Acute lymphoblastic leukemia (ALL), relapsed or refractory, failure to achieve hematologic remission after at least two high-dose therapy blocks 3. Patient eligible for current hematopoietic stem cell transplantation protocol 4. The BCL-2 expression must be detected on greater than 30% of tumor cells (AML and ALL) by flow cytometry 5. CD38 expression must be detected on greater than 30% of tumor cells (AML and ALL) by flow cytometry 6. CD184 7. Patients must have measurable or evaluable disease at the time of enrollment, which may include any evidence of disease including minimal residual disease detected by flow cytometry, cytogenetics, or polymerase chain reaction (PCR) analysis. 8. Patient Clinical Performance Status: Karnofsky \>50% or Lansky \>50% 9. Patient Life Expectancy \>12 weeks 10. Patients who agree to long-term follow up for up to 5 years Exclusion Criteria: * Age \>25 years * Patients with uncontrolled infections * Clearance of creatinine \< 70 ml/min * Cardiac ejection fraction \< 40% * Patients who can perform pulmonary function tests will be excluded if they have a diffusing capacity of the lung for carbon monoxide (DLCO) (corrected for hemoglobin) of \< 50% predicted; patients who are unable to perform pulmonary function tests will be excluded if the oxygen (O2) saturation is \< 92% on room air * Patients who have liver function test (LFTs) (including total bilirubin, aspartate aminotransferase \[AST\] and alanine aminotransferase \[ALT\]) \>= twice the upper limit of normal * Karnofsky/Lansky Scale \<70%