Cell-permeable. A second generation FLT3 receptor tyrosine kinase inhibitor. Quizartinib displays high affinity for FLT3 in a binding assay (Kd = 1.6 nM) and is a potent inhibitor in cellular autophosphorylation assays (IC₅₀ = 1.1 nM for FLT3-ITD and 4.2 nM for wt FLT3).  It inhibits the growth of human leukemia cell line MV4-11 (IC₅₀0 = 0.56 nM) which is FLT3 dependent and contains a homozygous FLT3-ITD mutation, and A375 cells (IC50 > 10,000 nM) which are not FLT3 dependent and contain an activating mutation in BRAF.