Salvage Chemotherapy With Sonrotoclax, Cladribine, and Standard-dose Cytarabine, Sequentially Followed by HSCT for R/R AML.

Inclusion Criteria:

* 1.Patients with a confirmed diagnosis of relapsed or refractory acute myeloid leukemia (AML) based on bone marrow morphology, immunophenotyping, and cytogenetics.
* 2\. Patients who are planned to undergo allogeneic hematopoietic stem cell transplantation, including HLA-matched or HLA-mismatched related allogeneic transplantation, as well as unrelated donor transplantation.
* 3\. Age between 18 and 65 years, inclusive, regardless of gender.
* 4\. Eastern Cooperative Oncology Group performance status (ECOG) of 0-2.
* 5\. Written informed consent must be obtained prior to the initiation of any study-related procedures. For patients aged 18 years or older, the consent form may be signed by the patient or by a direct relative. Should the patient's own signature be judged to be potentially harmful to their clinical care, consent may instead be given by a legal guardian or a direct relative.

Exclusion Criteria:

* 1\. Uncontrolled active infection (bacterial, fungal, or viral).
* 2\. Known positive serology for human immunodeficiency virus (HIV) or active hepatitis C virus (HCV).
* 3\. Psychiatric disorders or other medical conditions that preclude compliance with the study treatment and monitoring requirements.
* 4\. Pregnant patients, or patients who are unwilling or unable to use adequate contraceptive measures during the treatment period.
* 5\. Prior hematopoietic stem cell transplantation.
* 6\. Active cardiac disease, defined as one or more of the following: History of uncontrolled or symptomatic angina pectoris; Myocardial infarction within 6 months prior to study enrollment; History of arrhythmia requiring medication or clinically significant symptomatic arrhythmia; Uncontrolled or symptomatic congestive heart failure (\> New York Heart Association \[NYHA\] class 2); Ejection fraction below the lower limit of normal; Previous coronary angioplasty or stent implantation.
* 7\. Severe hepatic impairment, defined as liver function parameters (ALT, TBIL) \> 3 × upper limit of normal (ULN); or severe renal impairment, defined as serum creatinine (Cr) \> 2 × ULN, or 24-hour urine creatinine clearance \< 50 mL/min; or any other condition that, in the investigator's opinion, renders the patient unsuitable for treatment with the study drug.
* 8\. Any other condition that, in the investigator's opinion, makes the patient ineligible for study participation.