FLT3 and acute lymphoblastic leukemia: Despite very promising preclinical data, the randomized COG phase 3 trial AALL0631 (NCT00557193) failed to demonstrate benefit of lestaurtinib addition to chemotherapy in infants with KMT2A-rearranged ALL, although achievement of sustained FLT3 inhibition as measured by PIA assays was variable among patients and across therapy phases (68).