title: Validation of ITD mutations in FLT3 as a therapeutic target in human acute myeloid leukaemia.
abstract: Effective targeted cancer therapeutic development depends upon distinguishing disease-associated 'driver' mutations, which have causative roles in malignancy pathogenesis, from 'passenger' mutations, which are dispensable for cancer initiation and maintenance. Translational studies of clinically active targeted therapeutics can definitively discriminate driver from passenger lesions and provide valuable insights into human cancer biology. Activating internal tandem duplication (ITD) mutations in FLT3 (FLT3-ITD) are detected in approximately 20% of acute myeloid leukaemia (AML) patients and are associated with a poor prognosis. Abundant scientific and clinical evidence, including the lack of convincing clinical activity of early FLT3 inhibitors, suggests that FLT3-ITD probably represents a passenger lesion. Here we report point mutations at three residues within the kinase domain of FLT3-ITD that confer substantial in vitro resistance to AC220 (quizartinib), an active investigational inhibitor of FLT3, KIT, PDGFRA, PDGFRB and RET; evolution of AC220-resistant substitutions at two of these amino acid positions was observed in eight of eight FLT3-ITD-positive AML patients with acquired resistance to AC220. Our findings demonstrate that FLT3-ITD can represent a driver lesion and valid therapeutic target in human AML. AC220-resistant FLT3 kinase domain mutants represent high-value targets for future FLT3 inhibitor development efforts.
authors.affiliation: Division of Hematology/Oncology, University of California, San Francisco, California 94143, USA.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Smith
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Chen-Shan
authors.initials: CS
authors.lastname: Chin
authors.forename: Sara
authors.initials: S
authors.lastname: Salerno
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Damon
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Levis
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Perl
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Travers
authors.forename: Susana
authors.initials: S
authors.lastname: Wang
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Hunt
authors.forename: Patrick P
authors.initials: PP
authors.lastname: Zarrinkar
authors.forename: Eric E
authors.initials: EE
authors.lastname: Schadt
authors.forename: Andrew
authors.initials: A
authors.lastname: Kasarskis
authors.forename: John
authors.initials: J
authors.lastname: Kuriyan
authors.forename: Neil P
authors.initials: NP
authors.lastname: Shah
mesh_terms: D052160:Benzothiazoles / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D004252:DNA Mutational Analysis; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D058990:Molecular Targeted Therapy; D009154:Mutation / Q000235:genetics*; D010671:Phenylurea Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D011485:Protein Binding; D017434:Protein Structure, Tertiary / Q000235:genetics; D012008:Recurrence; D015203:Reproducibility of Results; D051941:fms-Like Tyrosine Kinase 3 / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism
chemical_list: D052160:Benzothiazoles; D010671:Phenylurea Compounds; C544967:quizartinib; C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3