In an open-label, single-center, phase 2 study of crenolanib in 38 R/R AML patients with FLT3-ITD or FLT3-TKD, ORR was 62% in FLT3 inhibitor-naïve patients and 38% in patients who had prior FLT3 inhibitor therapy [71]. This evidence concerns the gene FLT3 and acute myeloid leukemia.