[Pathogenesis and treatment of acute myeloid leukemia with FLT3 mutations]

FLT3 mutations are the most frequently identified genetic abnormalities in adult acute myeloid leukemia (AML) patients, accounting for approximately 30%. FLT3-ITD mutation specifically is considered as a poor prognostic factor in AML, and allogeneic hematopoietic cell transplantation in first remission is recommended for younger patients. The recent clinical introduction of FLT3 inhibitors has been reported to improve the prognosis of patients with FLT3 mutation-positive AML. In Japan, alongside monotherapy with gilteritinib or quizartinib for relapsed/refractory patients, combination of quizartinib with intensive chemotherapy was approved in 2023 for untreated FLT3-ITD mutation-positive AML. Studies to date have demonstrated the utility of measurable/minimal residual disease evaluation targeting FLT3 mutations and the efficacy of maintenance therapy after allogeneic transplantation. However, emergence of additional genetic mutations associated with treatment resistance has been observed. Thus, FLT3 mutations are utilized not only as a prognostic factor in AML but also as a target for treatment and for response assessment. Furthermore, the development of new treatment strategies involving FLT3 inhibitors is highly anticipated to improve clinical outcomes for patients with FLT3 mutation-positive AML.