Allogeneic or Haploidentical Stem Cell Transplant Followed By High-Dose Cyclophosphamide in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

Inclusion Criteria:

AML without complete remission (CR/CRc/CRi) after at least 2 induction therapies OR
AML that has relapsed within 6 months after obtaining a CR OR
AML that has relapsed more than 6 months after obtaining a CR, and has treatment failure (TF) or progressive disease (PD) following at least 1 re-induction regimen OR
AML that has relapsed post Allogeneic transplantation
Active AML (bone marrow blasts ≥ 5% by morphology, staining, or flow) and/or presence of estramedullary disease

Available HLA-haploidentical donor that meets the following criteria:

Blood-related family member (sibling (full or half), offspring, or parent, cousin, niece or nephew, aunt or uncle, or grandparent)
At least 18 years of age
HLA-haploidentical donor/recipient match by at least low-resolution typing per institutional standards
In the investigator's opinion, is in general good health, and medically able to tolerate leukapheresis required for harvesting HSC
No active hepatitis
Negative for HTLV and HIV
Not pregnant

NOTE: there were HLA-matched sibling and HLA-matched unrelated donor cohorts, but those closed without completion of accrual with Amendment 11

Karnofsky performance status ≥ 50 %

Adequate organ function as defined below:

Total bilirubin ≤ 2.5 mg/dl (unless the patient has a history of Gilbert's syndrome)
AST(SGOT) and ALT(SGPT) ≤ 3.0 x IULN
Creatinine ≤ 2.0 x IULN OR estimated creatinine clearance ≥ 30 mL/min/1.73 m2 by Cockcroft-Gault Formula
Oxygen saturation ≥ 90% on room air
LVEF ≥ 40%
FEV1 and FVC ≥ 40% predicted, DLCOc ≥ 40% predicted. If DLCO is < 40%, patients will still be considered eligible if deemed safe after a pulmonary evaluation.
At least 18 years of age at the time of study registration
Able to understand and willing to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable)

Exclusion Criteria:

Circulating blast count ≥ 10,000/uL by morphology or flow cytometry (cytoreductive therapies including leukapheresis or hydroxyurea are allowed)
Known HIV or Active hepatitis B or C infection
Known hypersensitivity to one or more of the study agents
Currently receiving or has received any investigational drugs within the 14 days prior to the first dose of study drug (Day -7)
Currently receiving or has received any intensive chemotherapy within the 14 days prior to the first dose of study drug (Day -7) (hydrea or other non-intensive regimens such as decitabine may be used but must stop at least one day prior to the first dose of study drug)
Pregnant and/or breastfeeding
Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, unstable cardiac arrhythmias, or psychiatric illness/social situations that would limit compliance with study requirements.