Prospective multicenter, open-lab el, observational, single arm study of decitabine. Subjects will be elderly patients with newly diagnosed, treatment-naïve AML who are unfit to receive and not candidate for intensive induction chemotherapy (iIC)

Inclusion Criteria:

1. Newly diagnosed and therapy-naïve AML (bone marrow or peripheral blood blast counts ≥20%)
2. 65 years of age or older
3. Taking informed consent with signature and date
4. Not eligible for iIC based on either:

i) ≥75 years of age ii) comorbidity iii) secondary AML iv) poor performance (ECOG ≥2) v) Poor-risk by NCCN Guideline version 1.2015 vi) subject's choice (refusal for iIC) investigator's judgement incompatible with iIC

Exclusion Criteria:

1. Candidate for iIC at the time of enrollment
2. Promyelocytic leukemia, or AML with t(15;17) or PML/RARα rearrangement
3. AML with t(9;22) or BCR/ABL rearrangement
4. Leukemia central nervous system involvement
5. Extramedullary myeloid sarcoma without bone marrow involvement
6. Prior treatment with decitabine or azacitidine of any cause
7. Any leukemia-specific therapy, except for hydroxyurea for reducing leukemic cells prior decitabine
8. Second malignancy currently requiring active therapy except breast or prostate cancer stable on or responding to endocrine therapy, or curatively resected non-melanoma skin cancer or intraepithelial cancer
9. Premenopausal woman
10. Severe active infection
11. Uncontrolled bleeding Hypersensitivity to decitabine

elderly patients with previously untreated AML who are ufit to receive and not considered candidates for iIC at the time of enrollment