To evaluate the feasibility, effectiveness and safety of chidamide combined with venetoclax and azacitidine in the treatment of newly diagnosed acute myeloid leukemia (AML) who are not suitable for intensive chemotherapy.

Inclusion Criteria:

• （1）Age ≥18 years old, no gender limit ;
• （2）be diagnosed with AML (non-M3) according to WHO 2016 standards;
• （3）No previous treatment;
• （4）Ineligible for intensive chemotherapy based on the following definitions: ≥75 years of age or 18 to 74 years of age with at least one of the following comorbidities: Eastern Cooperative Oncology Group (ECOG) performance status of 2 or 3 A history of cardiac disease such as congestive heart failure Treatment is required, or ejection fraction ≤ 50%, or chronic stable angina, diffusing capacity of lung for carbon monoxide (DLCO) ≤ 65%, or forced expiratory volume in first second (FEV1) ≤ 65%, creatinine clearance ≥ 30 mL/min to < 45 mL/min, moderate hepatic impairment, total bilirubin > 1.5 to ≤ 3.0 × ULN, other comorbidities that are not suitable for intensive chemotherapy in the physician's judgment.
• （5）Subjects must have an ECOG performance status score of: 0 to 2 for subjects aged ≥ 75 years or 0 to 3 for subjects aged ≥ 18 to 74 years.
• （6）Other comorbidities that are not suitable for intensive chemotherapy in the doctor's judgment;
• （7）Expected survival time ≥3 months;
• （8）Have the ability to understand and be willing to sign the informed consent form for this study.

Exclusion Criteria:

• (1) Combined with other malignant tumors
• (2) Have ever received treatment with chidamide and / or venetoclax or azacitidine;
• (3) The risk is assessed as low risk according to the NCCN 2022 guidelines [t(8;21)(q22;q22.1);RUNX1-RUNX1T1, inv(16)(p13.1q22) or t(16;16 )(p13.1;q22);CBFB-MYH11 ] ;
• (4) The subject is known to have AML central nervous system (CNS) infiltration;
• (5) Have undergone cardiac angioplasty or stent placement within 12 months before signing the informed consent form , or have a history of myocardial infarction, unstable angina, or other clinically significant heart disease;
• (6 ) Active infections (including bacterial, fungal or viral infections) and organ bleeding that cannot be controlled clinically;
• (7) Pregnant or lactating women;
• (8) Participated in any other clinical research within 3 months before signing the informed consent form ;
• (9 ) The researcher believes that it is not suitable to participate in this study;