A Single-Arm, Open Phase I Clinical Study of Selinexor in Combination With Azacitidine for the Treatment of High-Risk AML/MDS Patients After Allo-HSCT

Inclusion Criteria: 1. Voluntary participation in the clinical study: The subject or their legal guardian fully understands the study, provides informed consent by signing the Informed Consent Form (ICF), and is willing to comply with and complete all trial procedures. 2. Age \< 75 years at screening, regardless of gender. 3. Post-transplant MRD-negative acute myeloid leukemia / myelodysplastic syndrome with TP53 mutation. 4. No history of severe allergic constitution. 5. Liver function: ALT and AST ≤ 2.5 × upper limit of normal (ULN), and bilirubin ≤ 2 × ULN. 6. Renal function: Serum creatinine ≤ ULN. 7. No uncontrolled infection or severe psychiatric/psychological disorders. 8. Eastern Cooperative Oncology Group (ECOG) performance status of 0-3, with an estimated life expectancy of ≥ 4 months. 9. Bone marrow flow cytometry confirming MRD negativity prior to enrollment. 10. Successful myeloid and platelet engraftment. 11. No active graft-versus-host disease (GVHD). Exclusion Criteria: * (1) Patients with known allergy or contraindications to the investigational drugs. (2) Pregnant or breastfeeding female patients. (3) Presence of uncontrolled active infection or active graft-versus-host disease (GVHD). (4) Patients with long-term smoking or heavy alcohol consumption that may interfere with the evaluation of trial results. (5) Patients with psychiatric disorders or other conditions that preclude obtaining informed consent, or who are unable to comply with treatment and examination procedures. (6) Patients who have undergone major organ surgery within less than 6 weeks prior to enrollment. (7) Abnormal liver function: ALT and AST \> 2.5 × upper limit of normal (ULN), or bilirubin \> 2 × ULN; abnormal renal function: serum creatinine \> ULN. (8) Patients deemed unsuitable for this clinical trial by the investigator (e.g., poor compliance, drug abuse, etc.).