Treatment with FLT3 inhibitor in patients with FLT3-mutated acute myeloid leukemia is associated with development of secondary FLT3-tyrosine kinase domain mutations

Cancer. 2014 Jul 15;120(14):2142-9. doi: 10.1002/cncr.28705. Epub 2014 Apr 15.


Background: FLT3-internal tandem duplication (ITD) mutations are found in approximately 30% of patients with acute myeloid leukemia (AML). FLT3 inhibitors have shown clinical activity in AML with FLT3-ITD, but responses are usually short-lived.

Methods: This study examined 69 FLT3-mutated patients with AML, who were treated with different FLT3 inhibitors to analyze emergence of new mutations.

Results: At baseline, 87% of patients had an ITD mutation, 7% had a D835/I836 mutation, and 6% had combined ITD and D835/I836 mutations. Responses occurred in 32% of patients, all with FLT3-ITD; none of the patients with D835/I836 or ITD+D835/I836 responded. Mutational assessment at the time of FLT3 inhibitor discontinuation showed that 68% of patients were unchanged, 10% had become undetectable, and 22% of patients progressed from a single ITD to have combined ITD+D835/I836 mutations. In those patients with unchanged FLT3 mutation at progression, the median survival was 5 months, whereas in those with undetectable and with combined ITD+D835/I836 mutations, the median survival was 7 months, respectively.

Conclusions: These data confirm in vitro observations that a secondary tyrosine kinase domain mutation may arise after the use of FLT3 inhibitors in patients with single FLT3-ITD mutated AML, a phenomenon that is associated with resistance and a poor prognosis.

Keywords: FLT3 inhibitors; FLT3-ITD; FLT3-TKD; acute myeloid leukemia; secondary FLT3 mutations.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Benzothiazoles / therapeutic use
  • Carbazoles / therapeutic use
  • DNA Mutational Analysis
  • Female
  • Humans
  • Leukemia, Myeloid, Acute / drug therapy*
  • Leukemia, Myeloid, Acute / genetics*
  • Leukemia, Myeloid, Acute / mortality
  • Male
  • Medical Records
  • Middle Aged
  • Mutation*
  • Niacinamide / analogs & derivatives
  • Niacinamide / therapeutic use
  • Phenylurea Compounds / therapeutic use
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Retrospective Studies
  • Sorafenib
  • Survival Analysis
  • Treatment Outcome
  • fms-Like Tyrosine Kinase 3 / antagonists & inhibitors*
  • fms-Like Tyrosine Kinase 3 / genetics*


  • Antineoplastic Agents
  • Benzothiazoles
  • Carbazoles
  • Phenylurea Compounds
  • Protein Kinase Inhibitors
  • Niacinamide
  • quizartinib
  • Sorafenib
  • lestaurtinib
  • FLT3 protein, human
  • Protein-Tyrosine Kinases
  • fms-Like Tyrosine Kinase 3