HYML-122

Primary objective: To evaluate the efficacy of HYML-122 tablets combined with cytarabine in the treatment of relapsed or refractory acute myeloid leukemia (AML) with FLT3 mutation, explore the optimal dosing regimen, and provide a design basis for Phase III clinical trials. Secondary objectives: 1) To evaluate the pharmacokinetic characteristics of HYML-122 tablets in different dosing regimens in humans; 2) To observe and evaluate the efficacy differences through other secondary efficacy indicators; 3) To observe and evaluate safety, including clinical symptoms and signs observation and laboratory indicators, the incidence and severity of AEs (and SAEs).