Inclusion Criteria:

- ≥ 18 years of age

- Meets one of the following disease criteria:

- Primary acute myelogenous leukemia (AML) induction failure: no complete response
(CR )after 2 or more induction attempts

- Relapsed AML or Secondary AML (from MDS or treatment-related): not in CR after 1
or more cycles of standard induction therapy. For patients > 60 years of age
the 1 cycle of standard chemotherapy is not required if either of the following
is met:

- relapse within 6 months of last chemotherapy

- blast count <30% within 10 days of starting protocol

- AML relapsed > 2 months after transplant who do not have the option of donor
lymphocyte infusions (e.g. recipients of autologous or umbilical cord blood
[UCB] transplants)

Patients with prior central nervous system (CNS) involvement are eligible provided that it
has been treated and cerebrospinal fluid (CSF) is clear for at least 2 weeks prior to
enrollment. CNS therapy (chemotherapy or radiation) should continue as medically indicated
during the study treatment.

- Available related HLA-haploidentical donor (3-5 of 6 HLA-A, B and C)

- Karnofsky Performance Status > 50%

- Adequate organ function defined as:

- Creatinine: ≤ 2.0 mg/dL

- Hepatic: Liver function tests (LFT's) < 5 times upper limit of institutional
normal (ULN)

- Pulmonary Function: oxygen saturation ≥ 90% on room air and pulmonary function
>50% corrected DLCO and FEV1 Testing required only if symptomatic or prior known
impairment.

- Cardiac Function: Ejection fraction (EF) ≥ 40%, no uncontrolled angina, severe
uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute
ischemia or active conduction system abnormalities

- Able to be off prednisone or other immunosuppressive medications for at least 3 days
prior to Natural Killer (NK) cell infusion (excluding preparative regimen
pre-medications)

- Women of child bearing potential and men with partners of child bearing potential
must agree to use effective contraception during therapy and for 4 months after
completion of therapy.

- Voluntary written consent

Exclusion Criteria:

- Bi-phenotypic acute leukemia

- Transplant < 60 days prior to study enrollment

- Pregnant or breastfeeding - The agents used in this study include those that fall
under Pregnancy Category D - have known teratogenic potential. Women of child bearing
potential must have a negative pregnancy test within 14 days of study treatment start

- Active autoimmune disease

- History of severe asthma, presently on chronic medications (a history of mild asthma
not requiring therapy is eligible)

- New or progressive pulmonary infiltrates on screening chest x-ray or chest CT scan
that has not been evaluated with bronchoscopy, if feasible. Infiltrates attributed to
infection must be stable/improving (with associated clinical improvement) after 1
week of appropriate therapy (4 weeks for presumed or documented fungal infections).
Surgical resection waives any waiting requirements.

- Uncontrolled bacterial or viral infections - chronic asymptomatic viral hepatitis is
allowed

- Pleural effusion large enough to be detectable on chest x-ray

- Known hypersensitivity to any of the study agents used

- Received investigational drugs within the 14 days before enrollment

- Known active CNS involvement

Criteria For Initial Donor Selection:

- Related donors (sibling, parent, offspring, parent or offspring of an HLA identical
sibling)

- 14-75 years of age

- At least 40 kilogram body weight

- In general good health as determined by the evaluating medical provider

- HLA-haploidentical donor/recipient match (low resolution)

- Not pregnant

- Agree to undergo donor viral screening panel

- Able and willing to undergo apheresis

- Voluntary written consent