...Accompanied by KIT mutation 3....

...• Diagnostic criteria for refractory AML: Treatment-naïve patients refractory to 2 courses of standard regimen; patients who relapse within 12 months after consolidation and intensive treatment after CR; patients who relapse after 12 months but fail to respond to conventional chemotherapy; patients who relapse twice or more; and patients with persistent extramedullary leukemia; 3) Aged ≥ 14 years old (body surface area ≥ 1.2 m2 for patients aged 14 years), male or female (including 14 years old); 4) Patients with C-KIT D816 or C-KIT N822 mutation detected by bone marrow molecular biology, and with CBFB::MYH11 gene, or with RUNX1::RUNX1T1 fusion gene detected; 5) Performance status (ECOG PS) 0-2; 6) Adequate organ and bone marrow function, defined as follows: • Serum total bilirubin ≤ 1.5 × upper limit of normal (ULN), unless it is considered to be due to Gilbert’s syndrome or leukemia; • Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) ≤ 3.0 × ULN, unless considered to be due to leukemia; • Platelet count ≥ 20 × 109/L; • Serum creatinine ≤ 2.0 × ULN • Creatinine clearance rate > 40 mL/min based on estimated Cockcroft-Gault glomerular filtration rate (GFR); Note: Estimated glomerular filtration rate (eGFR, Cockcroft-Gault formula): Ccr = (140 - age) × weight (kg)/(72 × Scr (mg/dl)), calculated as × 0.85 for female; 7) Subjects must undergo bone marrow aspiration and/or biopsy to confirm diagnosis and evaluate AML; 8) Females of childbearing potential must agree to use contraception (e.g., intrauterine device, contraceptive pill, or condom) during the study and for 3 months after the end of the study; must have a negative serum pregnancy test within 7 days before study enrollment and must be non-lactating; male subjects must agree to use contraception during the study and for 3 months after the end of the study period....

Avapritinib is safe and effective in the prophylactic and preemptive treatment of AML with KIT mutation after allo-HSCT in children, which provides a clinical drug for the prevention of relapse after transplantation.