Anti-leukemic effects of FF-10101 in in vivo models. (A-B) MOLM-13 cells were injected into the tail vein of NOD/SCID mice. Mice were divided into 5 groups (n = 10/group) at 8 days after the injection. FF-10101 (2, 5, and 10 mg/kg) or quizartinib (5 mg/kg) was orally administered to mice once daily for 8 days. Mice were weighed at days 0, 4, and 8, and relative body weight to initial body weight (day 0) was represented as percent changes. At day 8, mice were euthanized and the percentage of human CD45-positive cells in the BM was determined by flow cytometry. The percentage of human CD45-positive cells in each mouse was plotted (panel A). No significant differences in body weight among groups were observed (panel B). Bars show mean ± standard deviation (SD). *P < .05 compared with control by Dunnett's Multiple Comparison Test. (C-E) 32D cells stably expressing FLT3-ITD, FLT3-ITD-D835Y, or FLT3-ITD-F691L were subcutaneously implanted into SCID mice. Mice were randomly divided into 5 groups (n = 5/group) when mean subcutaneous tumor volume reached 100 to 300 mm³. FF-10101 and quizartinib were orally administered at 5 and 10 mg/kg daily for 9 days for FLT3-ITD (panel C) and FLT3-ITD-D835Y (panel D), and at 10 and 20 mg/kg daily for 11 days for FLT3-ITD-F691L (panel E). Tumor volume was measured twice per week. No differences in body weight among groups were observed during the studies (data not shown). Data of tumor volume are represented as mean ± SD. *P < .05 compared with control by Dunnett's Multiple Comparison Test.