Bugitinib Combined With Venetoclax and Cytarabine in Relapsed/Refractory Acute Myeloid Leukemia

Inclusion Criteria: Participants must meet all of the following criteria: * Age 18-70 years (inclusive), regardless of sex; * Diagnosis of non-M3 acute myeloid leukemia (AML), and meeting at least one of the following conditions: * Failure to achieve complete remission (CR) after standard induction chemotherapy; * First CR duration ≤12 months; * First CR duration \>12 months, followed by relapse and failure of at least one line of standard chemotherapy; * Relapsed disease after ≥2 prior lines of therapy; * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2; * Estimated life expectancy ≥3 months; * Adequate organ function, defined as: * Cardiac: left ventricular ejection fraction (LVEF) ≥50% by echocardiography, with no clinically significant ECG abnormalities; * Renal: serum creatinine ≤2.0 × upper limit of normal (ULN) and creatinine clearance ≥60 mL/min (Cockcroft-Gault); * Hepatic: ALT and AST ≤3.0 × ULN; * Total bilirubin ≤2.0 × ULN (≤3.0 × ULN for patients with Gilbert syndrome); * Oxygen saturation ≥92% on room air; * Ability to take oral medications and comply with study procedures; * Willingness to participate and provide written informed consent. Exclusion Criteria: Participants meeting any of the following criteria will be excluded: * Known hypersensitivity to any study drug or its excipients; * Active central nervous system (CNS) leukemia (patients with prior CNS involvement who achieved complete remission and are clinically stable may be eligible); * Active, uncontrolled bacterial, viral, or systemic fungal infection; * Known hereditary bleeding or coagulation disorders, history of non-traumatic bleeding or thromboembolism, or other conditions that may increase bleeding risk; * Evidence of active infection, including: * Hepatitis B virus (HBV) infection with positive HBsAg or HBcAb and HBV DNA \>100 copies/mL; * Hepatitis C virus (HCV) antibody positive with detectable HCV RNA; * Human immunodeficiency virus (HIV) infection; * Positive test for syphilis; * Active bleeding or clinically significant bleeding tendency, including but not limited to: * Active gastrointestinal bleeding, intracranial hemorrhage, or bleeding in other vital organs; * Grade ≥3 bleeding event within 4 weeks prior to enrollment (per CTCAE); * Known hereditary bleeding disorders (e.g., hemophilia); * Severe platelet dysfunction not correctable; * Significant cardiovascular disease, including but not limited to: * New York Heart Association (NYHA) class III-IV heart failure; * Myocardial infarction or coronary artery bypass grafting (CABG) within 6 months prior to enrollment; * Clinically significant ventricular arrhythmias or unexplained syncope (excluding vasovagal or dehydration-related causes); * Severe cardiomyopathy; * History of or concurrent other malignancies (except for adequately treated basal cell carcinoma of the skin or carcinoma in situ of the cervix); * Clinically significant central nervous system disorders (e.g., epilepsy, stroke, psychiatric disorders) that may affect compliance or safety; * Participation in another interventional clinical trial within 30 days prior to enrollment; * Pregnant or breastfeeding women, or subjects planning pregnancy during the study period or within 6 months after the last dose and unwilling to use effective contraception; * Known or suspected drug abuse or alcohol dependence; * Requirement for concomitant use of strong CYP3A inhibitors or inducers that cannot be discontinued or dose-adjusted per protocol; * Any other condition that, in the investigator's opinion, would make the subject unsuitable for participation.