Second-generation FLT3i’s quizartinib and gilteritinib have high activity as single-agents in patients with R/R FLT3 AML who are FLT3 TKI naïve (46–67% CRc) or exposed to one prior FLT3 TKI (22–38% CRc). This evidence concerns the gene FLT3 and acute myeloid leukemia.