HEC73543 Versus Salvage Chemotherapy in R/R FLT3-ITD AML

Who May Qualify: - Subject is ≥ 18 years of age at the time of obtaining willing to sign a consent form. - Subject has a diagnosis of primary acute myeloid leukemia (AML) or AML secondary to myelodysplastic syndrome (MDS) according to WHO classification; - Subject is refractory to or relapsed after first-line AML therapy (with or without hematopoietic stem cell transplant ) - Subject is positive for FLT3 mutation in bone marrow or whole blood as determined by the central lab - Subject has an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 - Subject is eligible for pre-selected salvage chemotherapy at the investigator's discretion Who Should NOT Join This Trial: - Subject has received prior treatment with other FLT3 inhibitors - Subject has AML that has relapsed after or is refractory to more than 1 line of therapy - Subject has an active uncontrolled infection - Subject is known to have human weakened immune system virus infection - Subject has any condition which, in the investigator's opinion, makes the subject unsuitable for study participation Always talk to your doctor about whether this trial is right for you.