FLT3 ITD-IN-1 (Compound 1) is a highly potent inhibitor of FLT3 internal tandem duplications (FLT3-ITD). It exhibits remarkable inhibitory effects against FLT3 and FLT3-ITD, with impressive IC50 values of 38.2 nM and 144.1 nM, respectively. Moreover, FLT3 ITD-IN-1 shows exceptional antiproliferative activities against several acute myeloid leukemia cell lines [1].