Antileukemic properties of merestinib in vitro and in vivo. (A) Expression of cell cycle markers in merestinib-treated MV4-11 cells. Cells were treated with or without merestinib (10 nM) for the indicated times. Whole cell lysates were evaluated by western blot analysis with the indicated antibodies. (B-C) MV4-11 cells were incubated for 24 and 48 hours in the presence or absence of merestinib (LY2801653) at the indicated doses. Whole cell lysates were analyzed by western blot with the indicated antibodies. (D-F) MM6 cells were injected subcutaneously into the left flank of nu/nu mice (n = 10). Once tumors reached a measurable size, mice were divided into control (vehicle-Captisol) and merestinib (LY2801653) (12 mg/kg)-treated groups. (D) Mice body weight was recorded throughout the study. (E) Average of tumor volumes treated with vehicle or merestinib. Data are means ± SE of tumor volumes. Mann-Whitney test was used to assess statistically significant differences between the 2 treatment groups (*P < .05, **P < .01, ***P < .001). The arrow symbols indicate that mice were killed when significant morbidity was observed as described in the Study design. (E) Kaplan-Meier survival analysis of control and merestinib-treated mice, P = .0006, using a log-rank (Mantel-Cox) test.