1. MDS patients diagnosed due to bone marrow morphology and immunophenotyping (met the World Health Organization(WHO) 2016 diagnosis criterion) and met revised the International Prognostic Scoring System(IPSS) prognostic risk categories intermediate(\>3-≤4.5), high(\>4.5-≤6), and very high risk(\>6), or CMML-2(PB 5-19% or bone marrow 10-19% blast equivalent, and/or when any Auer rods are present) patients diagnosed due to bone marrow morphology and immunophenotyping (met the WHO 2016 diagnosis criterion) with white blood cell count(WBC)\<13x109/L, or AML patients diagnosed due to bone marrow morphology and immunophenotyping (met the WHO 2016 diagnosis criterion) with history of myeloid neoplasms ;
2. Ineligible for allogeneic hematopoietic stem cell transplantation (HSCT) based on local medical standards and clinical decision guidelines in the study;
3. Indications for azacytidine (AZA) treatment were determined according to local medical standards and diagnostic decision guidelines in the study;
4. Morphology and immunophenotyping excluded BCR/ABL positive chronic myelogenous leukemia and other myeloid neoplasms including essential thrombocythemia, polycythemia vera and primary myelofibrosis;
5. Aged 18-80 years old;
6. Alanine transaminase(ALT), Aspartate Transaminase(AST) and serum bilirubin \<=2 upper limit of normal (ULN), serum creatinine \<=150umol/L, myocardial enzyme \<2xULN (of the same age);
7. Left ventricularinjection fraction(LVEF)\>=50% by echocardiogram;
8. Estimated glomerular filtration rate (eGFR) ≥30mL/min/1.73m2 ;
9. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2; 10. must sign (or their legally-acceptable representative must sign) an informed consent form indicating that he or she understands the purpose of and procedures required for the study and are willing to participate in the study.
Exclusion Criteria:
1. BCR/ABL positive chronic myelogenous leukemia, primary myelofibrosis, polycythemia vera and essential thrombocythemia;
2. Low risk myelodysplastic syndromes according to IPSS or revised IPSS prognostic risk categories;
3. Acute promyelocytic leukemia, myeloid sarcoma, or accelerated or blastic phase of chronic myelogenous leukemia;
4. Allergic to any of the mentioned agent in the study protocol;
5. Pregnant or lactating women, or patients during reproductive stage but not willing to take contraception methods;
6. With obvious dysfunction of liver or kidney, not fulfilling the inclusion criteria;
7. With organic heart disease, which causes clinical symptoms or cardiac dysfunction ( ≥ Class 2 cardiac disease as defined by the New York Heart Association Functional Classification, NYHA );
8. At the same time suffering from other malignant tumors, with the exception of the following: (1) malignancy treated with curative intent and with no evidence of active disease present for more than 5 years prior to screening; (2) adequately treated lentigo maligna melanoma without current evidence of disease or adequately-controlled non-melanomatous skin cancer (even if less than 3 years prior to screening); (3) adequately treated cervical carcinoma in situ without current evidence of disease (even if less than 3 years prior to screening);
9. Known history of human immunodeficiency virus (HIV) or syphilis, or active infection with Hepatitis B (HBV-DNA positive) or Hepatitis C;
10. Currently active clinically significant cardiovascular disease such as uncontrolled arrhythmia, congestive heart failure, or history of myocardial infarction within 6 months prior to first dose with study drug, or any Class 3 or 4 cardiac disease as defined by NYHA;
11. Any concurrent medical condition or disease (eg, active systemic infection) that may interfere with the research procedure or outcome, or that the subject may have a risk to participate in the study;
12. Cannot understand or follow the study protocol;
13. Patients under 12 years old or over 80 years old;
14. Received major surgery within 4 weeks prior to randomization;
15. Participated in other clinical researches at the same time one month before enrollment;
16. Cannot matching suitable cord blood stem cell;
17. Addicted to illegal drugs;
18. Have mental disorders or cognitive disorders.
