Venetoclax, Chidamide, and Chiglitazar Sodium (VCC) in Patients With Relapsed/Refractory Acute Myeloid Leukemia

Inclusion Criteria: 1. Histologically confirmed acute myeloid leukemia (AML) with relapsed or refractory disease, including: * Refractory AML, defined as failure to achieve remission after at least one prior treatment; * Relapsed AML, defined as ≥5% blasts in the bone marrow after a previous remission; * AML arising from myelodysplastic syndrome (including CMML) or myeloproliferative neoplasms (secondary AML or therapy-related AML \[t-AML\]) is also eligible. 2. Age ≥18 years, regardless of sex, with an expected survival of \>3 months. 3. Estimated creatinine clearance ≥50 mL/min. 4. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3.0 × the upper limit of normal (ULN), unless the abnormality is considered attributable to leukemic organ involvement; total bilirubin ≤3.0 × ULN, unless the abnormality is considered attributable to leukemic organ involvement. 5. Eastern Cooperative Oncology Group (ECOG) performance status ≤2. 6. Participants must not be pregnant and must agree to use effective contraception during study treatment. 7. Ability to understand the study and willingness to provide written informed consent. Exclusion Criteria: 1. Acute promyelocytic leukemia (APL). 2. Active central nervous system leukemia. 3. Clinically significant cardiovascular disease, including any of the following: * Clinically significant QTc prolongation (QTc \>450 ms in males or \>470 ms in females); * Ventricular tachycardia; * Second-degree atrioventricular block; * Myocardial infarction within 1 year prior to enrollment; * Congestive heart failure; * Coronary artery disease requiring medical treatment. 4. Active, uncontrolled severe infection. 5. Other non-hematologic malignancies within the previous 2 years. 6. Psychiatric disorders that may interfere with participation in the study. 7. Previous solid organ transplantation. Prior stem cell transplantation (SCT) is permitted; however, patients with graft-versus-host disease (GVHD) or those receiving ongoing immunosuppressive or GVHD-directed therapy are not eligible. 8. Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in the study.