Alloreactive NK Cells for Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

1.5 mg/kg By Vein Daily x 3 Days

130 mg/m\^2 By Vein Over 3 Hours x 4 Days

40 mg/m\^2 By Vein Over 30 Minutes x 4 Days

Alloreactive NK infusion from haploidentical donor on Day -8. The alloreactive NK cell infusion given at one of 4 dose levels 10e6, 5 x 10e6, 3 x 10e7 cells/kg and 3 x10e7.

5 mcg/kg/day subcutaneously beginning on Day +7, and continuing until absolute neutrophil count (ANC) is \> 500 x 109/L for 3 consecutive days.

Starting dose of 0.015 mg/kg as a 24 hour continuous infusion daily adjusted to achieve a therapeutic level of 5-15 ng/ml. Tacrolimus changed to oral dosing when tolerated and can be tapered off after Day +90 if no GVHD is present.

5 mg/m2 intravenously on Days 1, 3 and 6 and Day +11 post transplant.

0.5 million units per day subcutaneously starting on Day -8 (day of the NK cell infusion) to Day -4 only to participants receiving fourth dose level of NK cells.