Quizartinib, also know as AC220 and AC010220, is an orally available FLT3 STK1 inhibitor with potential antineoplastic activity. Class III receptor tyrosine kinase inhibitor AC220 selectively inhibits class III receptor tyrosine kinases, including FMS-related tyrosine kinase 3 (FLT3 STK1), colony-stimulating factor 1 receptor (CSF1R FMS), stem cell factor receptor (SCFR KIT), and platelet derived growth factor receptors (PDGFRs), resulting in inhibition of ligand-independent leukemic cell proliferation and apoptosis. Mutations in FLT3, resulting in constitutive activation, are the most frequent genetic alterations in acute myeloid leukemia (AML) and occur in approximately one-third of AML cases.