Blinatumomab Prevents Recurrence of R/R ALL After Allo-HSCT

Inclusion Criteria: B-ALL patients with history of relapse, or MRD positive in the last bone marrow examination before allo-HSCT; Age ≥16 years old and ≤ 65 years old when signing informed consent Form (ICF); KPS > 60 or ECOG 0-2; The expected survival time is more than 3 months; Complete remission (CR) after allo-HSCT with either myeloablative or non-myeloablative conditioning regimen determined by the investigator; Reach the standard of hematopoietic reconstitution (neutrophil count ≥ 0.5×10^9/L for 3 consecutive days without G-CSF application, platelet count ≥ 20×10^9/L for 7 consecutive days without platelet transfusion, Hb ≥ 80 g /L without red blood cell transfusion); and neutrophil count ≥ 1.5×10^9/L, platelet count ≥ 50×10^9/L within 45 days after transplantation; No central nervous system involvement or clinical symptoms after transplantation; Those who have no serious functional damage to important organs of the body; Fully understand and be informed of this study and sign the ICF; willing to follow and have the ability to complete all test procedures; Females of childbearing age must afford a serum pregnancy test within 7 days before the first dose, and the result should be negative; female participants and their partners should agree to use effective contraception from signing the ICF until 6 months after the last dose. Exclusion Criteria: Serious basic diseases of important organs: such as myocardial infarction, chronic cardiac insufficiency, decompensated hepatic insufficiency, renal function, gastrointestinal insufficiency, etc.; Uncontrolled active infection (including bacterial, fungal, or viral infection), and drug treatment is ineffective; Participating in other clinical studies, or planning to start treatment in this study and less than 4 weeks before the end of treatment in the previous clinical study; Poor graft function (PGF) occurred after allo-HSCT; Combined with other malignant tumors and require treatment; Active GVHD; Have a history of allergy to Chidamide; Pregnant or lactating females; Patients with known history of human immunodeficiency virus (HIV) virus infection and/or acquired immunodeficiency syndrome; Patients with active chronic hepatitis B or active hepatitis C; History of prolonged QT syndrome; Patients considered by other researchers to be unsuitable for this study