Chidamide Plus DCAG for Relapsed/Refractory AML

Inclusion Criteria: * Men and women whose age more than 18 and less than 59； * Patients diagnosed as AML according to the 2008 WHO (WHO) myeloid malignant disease diagnosis standard; * Patients who relapsed after remission or who can not achieve remission after at least two cycle of systemic therapy (including chemotherapy, hematopoietic stem cell transplantation, etc.); * ECOG performance status 0-3; * Expected survival time ˃ 3 months; * Patients without serious hearts, lung, liver, kidney disease; * Patients have not received radiotherapy, chemotherapy, targeted therapy or hematopoietic stem cell transplantation and other treatment within 4 weeks prior to the enrollment; * Patients are able to understand and willing to sign informed consent. Exclusion Criteria: * Patients who allergy to the study drug or the drug with similar chemical structure;; * Pregnancy, lactation women and women of childbearing age who do not want to practice effective methods of contraception; * Active infection; * Drug abuse, long-term alcohol abuse so as to affect the results of the evaluation of patients; * Patients with mental disorders or other conditions can not obtain informed consent, can not meet the requirements of the study treatment and procedures; * Patients have clinical significant QTc interval prolongation history (male \> 450ms. Female \>470ms), ventricular heart had tachycardia (VT) and atrial fibrillation (AF), II degree heart block, myocardial infarction attack (MI) within 1 year prior to the enrollment, congestive heart failure (CHF), patients of coronary heart disease who have clinical symptoms and need drug treatment. * Cardiac ultrasound showed that the diastolic pericardial fluid dark area width ˃ 10mm; * Patients have received organ transplantation; * Active bleeding * Patients have new thrombosis, embolism, cerebral hemorrhage and other diseases or medical history of patients within 1 year prior to enrollment; * The main organs of the surgery is less than 6 weeks; * Bone marrow hyperplasia and WBC \<2.0 \* 10\^9/L; * Liver function abnormalities (total bilirubin \> 1.5 times of upper limit of normal range , ALT / AST \> 2.5 times of the upper limit of normal range or patients with liver involvement whose ALT / AST \> 1.5 times of upper limit of normal range), renal anomalies (serum creatinine \> 1.5 times of upper limit of normal value ); * Not suitable for the study according to investigator's assessment.