XY0206

Phase I dose escalation: Study objectives: 1. To evaluate the safety and tolerability of XY0206 tablets combined with DA (daunorubicin + cytarabine) in the treatment of first-line AML subjects with FLT3-ITD mutations, observe dose-limiting toxicity (DLT), and determine the recommended Phase II dose (RP2D); 2. To evaluate the pharmacokinetic (PK) characteristics of XY0206 tablets combined with DA (daunorubicin + cytarabine) in the treatment of first-line AML subjects with FLT3-ITD mutations; 3. To evaluate the preliminary efficacy of XY0206 tablets combined with DA (daunorubicin + cytarabine) in the treatment of first-line AML subjects with FLT3-ITD mutations (if available). Phase II randomized controlled study: Study objectives: 1. To compare the efficacy of XY0206 tablets combined with DA (daunorubicin + cytarabine) and placebo combined with DA in the treatment of first-time AML subjects with FLT3-ITD mutations; 2. To compare the safety and tolerability of XY0206 tablets combined with DA (daunorubicin + cytarabine) and placebo combined with DA in the treatment of first-time AML subjects with FLT3-ITD mutations; 3. To evaluate the pharmacokinetic (PK) characteristics of XY0206 tablets combined with DA (daunorubicin + cytarabine) in the treatment of first-time AML subjects with FLT3-ITD mutations.