Low-dose Chidamide Maintenance Therapy After Allo-HSCT for T-cell Acute Lymphoblastic Leukemia or T-cell Lymphomas

Inclusion Criteria: 1. T-cell acute lymphoblastic leukemia or T-cell lymphomas (mainly including peripheral T-cell lymphoma, NK/T-cell lymphoma, T-lymphoblastic lymphoma, etc.) must be diagnosed before enrollment. The diagnostic criteria refer to the 2016 WHO classification. Patients is in high-risk group or standard-risk group with MRD-positive patients after transplantation. 2. Age 14-70; 3. Stable hematopoietic reconstitution after receiving allogeneic hematopoietic stem cell transplantation, no aGVHD or stable aGVHD control and stable primary disease; 4. Complete donor chimerism after transplantation; 5. During the screening period after transplantation (within 4 weeks before Chidanilide administration), the primary disease is remission and MRD is negative. 6. Eastern Cooperative Oncology Group (ECOG) physical condition score is 0-2 points; 7. Creatinine clearance ≥ 60 mL/min (according to the Cockcroft-Gault formula); 8. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3 × upper limit of normal range (ULN), total bilirubin ≤ 2 × ULN; 9. Echocardiography (ECHO) shows left ventricular ejection fraction (LVEF) ≥ 50% 10. Life expectancy \>8 weeks; 11. Voluntarily sign the informed consent form, understand and comply with the requirements of the research. Exclusion Criteria: 1. Bone marrow recurrence or extramedullary recurrence after transplantation; 2. Hemocytopenia after transplantation: white blood cells \<2000/ul, platelets \<25000/ul; 3. Active grade 3-4 acute GVHD, or active moderate-to-severe chronic GVHD that cannot be controlled by drugs; 4. Active autoimmune diseases, such as SLE, rheumatoid arthritis, etc.; 5. Currently suffering from clinically significant active cardiovascular disease, such as uncontrolled arrhythmia, prolonged QTc interval of electrocardiogram, uncontrolled uncontrolled hypertension, congestive heart failure, any New York Heart Association (NYHA) functional class 3 or 4 cardiac disease, or a history of myocardial infarction within 6 months before screening; 6. Other serious diseases that may limit patients to participate in this trial (such as advanced infection, uncontrolled diabetes, renal failure); 7. Known human immunodeficiency virus (HIV) infection, or hepatitis B virus that cannot be controlled by drugs (HBV-DNA positive, and HBV DNA test value above the upper limit of normal value) or hepatitis C virus (anti-HCV positive, and HCV viral titer detection value above the upper limit of normal value) Chronic Infect; 8. Pregnant or lactating women; 9. Those who cannot understand and follow the research protocol or cannot sign the informed consent form;