Combination of Venetoclax, Hypomethylation Agent and Low-dose Cytarabine as a Salvage Therapy for Acute Myeloid Leukemia

Inclusion Criteria: 1. Aged ≥18 years old, voluntarily participate in clinical research and sign an informed consent form and be willing to follow and be able to complete all experimental procedures. 2. The toxic and side effects caused by the last treatment should be recovered. 3. Eastern Cooperative Oncology Group score of 0 to 3 points. 4. The organ function is intact. * Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) ≤2.5×ULN (Upper Limit of Normal). * Creatinine≤1.5×ULN. * Bilirubin≤1.5×ULN. 5. Karnofsky≥70. 6. The expected survival period is at least 12 weeks. 7. Non-pregnant, non-breastfeeding women. Exclusion Criteria: 1. Suffering from other untreated or unrelieved malignant tumors within 2 years. 2. Major surgery, radiotherapy, chemotherapy, biological therapy, immunotherapy, and experimental therapy were performed within 2 weeks of the first medication. 3. Suffering from any other known serious and/or uncontrolled disease (eg, uncontrolled diabetes; cardiovascular disease, including congestive heart failure New York Heart Association \[NYHA\] Class III or IV, 6 months patients with myocardial infarction and poorly controlled blood pressure); chronic renal failure; or active uncontrolled infection); the investigators considered unsuitable for this clinical trial. 4. Patients who are unwilling or unable to comply with the protocol. 5. Currently being treated with other systemic anti-tumor or anti-tumor research drugs. 6. Women who are pregnant or breastfeeding.