Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
National Center of Tumor Diseases, German Cancer Research Center, Heidelberg, Germany.
Leukemia. 2019 Feb;33(2):299-312. doi: 10.1038/s41375-018-0357-9. Epub 2019 Jan 16.
Genomic investigations of acute myeloid leukemia (AML) have demonstrated that several genes are recurrently mutated, leading to new genomic classifications, predictive biomarkers, and new therapeutic targets. Mutations of the FMS-like tyrosine kinase 3 (FLT3) gene occur in approximately 30% of all AML cases, with the internal tandem duplication (ITD) representing the most common type of FLT3 mutation (FLT3-ITD; approximately 25% of all AML cases). FLT3-ITD is a common driver mutation that presents with a high leukemic burden and confers a poor prognosis in patients with AML. The prognostic value of a FLT3 mutation in the tyrosine kinase domain (FLT3-TKD), which has a lower incidence in AML (approximately 7-10% of all cases), is uncertain. Accumulating evidence demonstrates that FLT3 mutational status evolves throughout the disease continuum. This so-called clonal evolution, together with the identification of FLT3-ITD as a negative prognostic marker, serves to highlight the importance of FLT3-ITD testing at diagnosis and again at relapse. Earlier identification of FLT3 mutations will help provide a better understanding of the patient's disease and enable targeted treatment that may help patients achieve longer and more durable remissions. First-generation FLT3 inhibitors developed for clinical use are broad-spectrum, multikinase inhibitors; however, next-generation FLT3 inhibitors are more specific, more potent, and have fewer toxicities associated with off-target effects. Primary and secondary acquired resistance to FLT3 inhibitors remains a challenge and provides a rationale for combining FLT3 inhibitors with other therapies, both conventional and investigational. This review focuses on the pathological and prognostic role of FLT3 mutations in AML, clinical classification of the disease, recent progress with next-generation FLT3 inhibitors, and mechanisms of resistance to FLT3 inhibitors.
急性髓系白血病（AML）的基因组研究表明，几个基因经常发生突变，导致新的基因组分类、预测生物标志物和新的治疗靶点。FMS 样酪氨酸激酶 3（FLT3）基因的突变发生在大约 30%的所有 AML 病例中，内部串联重复（ITD）是最常见的 FLT3 突变类型（FLT3-ITD；约占所有 AML 病例的 25%）。FLT3-ITD 是一种常见的驱动突变，具有高白血病负担，并在 AML 患者中预后不良。酪氨酸激酶结构域（FLT3-TKD）中的 FLT3 突变的预后价值不确定，其在 AML 中的发生率较低（约占所有病例的 7-10%）。越来越多的证据表明，FLT3 突变状态在整个疾病连续体中不断演变。这种所谓的克隆进化，以及将 FLT3-ITD 鉴定为负预后标志物，突出了在诊断时和复发时再次进行 FLT3-ITD 检测的重要性。更早地识别 FLT3 突变将有助于更好地了解患者的疾病，并能提供靶向治疗，可能帮助患者实现更长和更持久的缓解。为临床应用而开发的第一代 FLT3 抑制剂是广谱、多激酶抑制剂；然而，下一代 FLT3 抑制剂更具特异性、更强效，并且与脱靶效应相关的毒性更少。FLT3 抑制剂的原发性和获得性耐药仍然是一个挑战，并为将 FLT3 抑制剂与其他治疗方法（包括常规和研究性治疗方法）联合提供了依据。本综述重点关注 FLT3 突变在 AML 中的病理和预后作用、疾病的临床分类、新一代 FLT3 抑制剂的最新进展以及 FLT3 抑制剂耐药的机制。
