VA Combined With PD-1 Inhibitor for the Treatment of Relapsed and Refractory AML and High-risk MDS

Inclusion Criteria: * Patients diagnosed with relapsed and refractory acute myeloid leukemia (AML) and patients diagnosed with myelodysplastic syndrome (MDS) who require chemotherapy treatment. * Patients who did not respond or had disease recurrence after 1 course of induction chemotherapy or had positive immune residues after induction chemotherapy or positive molecular residues (if any) after induction chemotherapy. * Voluntarily participate in clinical research and sign an informed consent form and be willing to follow and be able to complete all experimental procedures. * The toxic and side effects caused by the last treatment should be recovered. * Eastern Cooperative Oncology Group score of 0 to 3 points. * The organ function is intact. * Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) ≤2×ULN (Upper Limit of Normal). * Creatinine≤2×ULN. * Bilirubin≤2×ULN. * Karnofsky≥70. * The expected survival period is at least 12 weeks. * Non-pregnant, non-breastfeeding women. Exclusion Criteria: * Suffering from other untreated or unrelieved malignant tumors within 2 years. * Major surgery, radiotherapy, chemotherapy, biological therapy, immunotherapy, and experimental therapy were performed within 2 weeks of the first medication. * 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. * Patients who are unwilling or unable to comply with the protocol. * Currently being treated with other systemic anti-tumor or anti-tumor research drugs. * Women who are pregnant or breastfeeding.