Figure 4.

Anti-leukemic activity of CAR-NK-92 cells in vivo. (a) Reduction of AML blasts in peripheral blood following infusion of 5 × 10⁶ Δ-CAR-NK-92 or full-length CAR-NK-92 cells. # All Δ-CAR-NK-92 died or were sacrificed due to illness one week earlier. (b) Persistence of hIL-15-expressing Δ-CAR-NK-92 and CAR-NK-92 cells as measured by the hCD45⁺CD56⁺ population. (c) AML burden at time of sacrifice. AML blast percentages were determined in the peripheral blood, spleen, and bone marrow via flow cytometric analyses for hCD45⁺CD123⁺ cells. (d) NK cell persistence at time of sacrifice. NK-92 levels were determined in the peripheral blood, spleen and bone marrow via flow cytometric analyses for hCD45⁺CD56⁺ cells. (e) and (f) show the AML level and NK-92 cell persistence at the time of sacrifice as in panels c and d, respectively, but the two mice in the CAR-NK-92 group that showed no NK-92 persistence were excluded. Data are shown as mean ± standard error of mean (SEM) and the unpaired t-test was used to assess differences between groups. Statistically significant differences are indicated by * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).