Mutations in the FMS-like tyrosine kinase 3 (FLT3) gene are detected in approximately 30% of acute myeloid leukemia (AML). The high frequency of FLT3 mutations, along with their adverse effect on prognosis, makes FLT3 a promising therapeutic target, and has spurred development of FLT3 inhibitors. First-generation inhibitors, including midostaurin and sorafenib, lack specificity for FLT3 and act on multiple kinases, whereas second-generation inhibitors, including gilteritinib, and quizartinib, are highly specific to FLT3 and are more potent than first-generation inhibitors. Several FLT3 inhibitors have recently gained regulatory approval worldwide, and several others are under development. The advent of FLT3 inhibitors has changed the standard treatment for FLT3-mutated AML in the frontline and relapsed/refractory settings and contributed to improved outcomes for this formidable AML subtype. However, numerous unresolved issues remain owing to rapid changes in practice. These include identification of optimum FLT3 inhibitors and combination therapies, the role of maintenance therapy, and the indication for allogeneic hematopoietic cell transplantation. Furthermore, strategies to overcome resistance to FLT3 inhibitors must be pursued. Results of ongoing and future studies will improve our ability to use FLT3 inhibitors more effectively, which should provide significant benefits to a wider range of patients.
Keywords: Acute myeloid leukemia; Allogeneic hematopoietic cell transplantation; FLT3; Targeted therapy.
© 2022. Japanese Society of Hematology.