NK DLI products containing >1 10e7 NK cells/kg bodyweight (BW) and < 1 x 10e5 T-cells/kg BW are administered at days +4 (Frankfurt only), and on days +40 and +100 (both centers)

The feasibility of the production of expanded NK-cell DLI will be measured. Primary quality measures of the NK cell product are the number of NK cells that can be produced (CD56+/cluster of differentiation 3(CD3)- NK cell goal dose >= 1 * 10e7/kg body weight of recipient) as well as the degree of CD3 T-cell contamination (goal CD3+ T-cell dose < 1 * 10e5 / kg body weight of recipient).

The safety evaluation regards transfusion associated adverse events (fever, fall in blood pressure, transfusion site reactions, etc) and is evaluated at the time of NK DLI infusion. The primary long-term safety measure is the absence of acute graft-versus-host disease 30 days after the last NK DLI infusion.

The efficacy of NK DLI infusions will be assessed by evaluation of the rates of overall and disease free survival and the rate of disease relapse. As this is a single arm study, outcome measures assessed will be compared to those of historical controls treated with haploidentical HSCT without NK DLI infusions.