Avapritinib Maintenance for AML With KIT Mutations

Inclusion Criteria: * Age≥ 14 years old; * First allo-HSCT for AML (including secondary AML) ; * KIT mutation at diagnosis (no restriction on locus for kit mutation * CR and negative MFC-MRD prior to initiation of maintenance therapy; * Absolute neutrophil count ≥ 1.0 x 109 /L, platelets ≥ 75 x 109 /L, hemoglobin ≥ 80 g/L before maintenance; * Normal functioning of major organs and laboratory findings in accordance with the following criteria:AST and ALT) ≤ 3x ULN; Total serum bilirubin ≤ 1.5x ULN unless the patient has Gilbert syndrome; patients with Gilbert-Meulengracht syndrome with bilirubin ≤ 3.0 times the upper limit of normal and direct bilirubin ≤ 1.5 times the upper limit of normal may be included; HB ≥ 70 g/L (had not received a red blood cell transfusion within 1 week prior to administration); ANC ≥ 0.8 x 10\^9/L (had not received long-acting colony-stimulating factor (LACSF) within 1 week prior to administration and short-acting colony-stimulating factor (SACSF) within 3 days prior to administration); Platelet count ≥ 20 x 10\^9/L (had not received a platelet transfusion within 1 week prior to administration); serum creatinine ≤ 1.5x ULN or creatinine clearance ≥ 60 mL/min; Coagulation function: International Normalized Ratio (INR) ≤1.5×ULN, Activated Partial Thromboplastin Time (APTT) ≤1.5×ULN; Left ventricular ejection fraction (LVEF) ≥45%; * ECOG PS 0-2 points; * Expected survival ≥ 3 months; * Patient consent Exclusion Criteria: * concurrently receiving other targeted therapies for AML; * Prior treatment with a TKI inhibitor that proved ineffective; * with concurrent FLT3-ITD mutations at enrollment; * Acute/chronic graft-versus-host disease requiring systemic immunosuppressive therapy prior to maintenance therapy; * Accompanied by other malignant tumors requiring treatment; * Have important organ-based diseases: e.g., myocardial infarction, chronic cardiac insufficiency, decompensated hepatic insufficiency, renal failure; * Active, uncontrolled infection; * HIV-positive, active hepatitis B (HBV) or active hepatitis C (HCV) requiring antiviral therapy; * Other interventional clinical studies have been enrolled; * Men and women of childbearing potential are unwilling to use contraception during and for 12 months after treatment; * The investigator believes that there are other conditions that make the patient unsuitable for participation in this study.