CSL362-mediated ADCC targets BC-CML leukemia-initiating cells. MNCs from patient BC-CML 4 (A-B) and BC-CML 5 (C) were incubated with 1 µg/mL CSL362 or BM4 isotype control antibody, without or with 1 µM nilotinib, in the presence of purified NK cells (E:T 1:1) overnight prior to intravenous transplantation into sub-lethally irradiated NOD/SCID mice. Human engraftment was analyzed by flow cytometry 12 weeks postinjection. (A) Representative flow plots for positive BM engraftment 12 weeks postinjection in a mouse from the BM4 group and for eliminated engraftment in a mouse from the CSL362 group are shown. The middle panel documents CD123 expression in engrafted cells. (B-C) Percentages of engraftment in BM and spleen of individual mice and the group means are plotted. Mice injected with BC-CML 5 cells did not show significant engraftment in the spleen. P values were determined by Mann-Whitney test.