De novo ALK kinase domain mutations are uncommon in kinase inhibitor-naïve ALK rearranged lung cancers

Lung Cancer. 2016 Sep;99:17-22. doi: 10.1016/j.lungcan.2016.06.006. Epub 2016 Jun 14.

Abstract

Introduction: Anaplastic lymphoma kinase (ALK) rearranged lung adenocarcinomas are responsive to the multitargeted ALK inhibitor crizotinib. One of the common mechanisms of resistance to crizotinib is the acquisition of ALK kinase domain mutations. However, the presence of ALK mutations in crizotinib-naïve tumors has not been widely reported and it is unclear if de novo ALK mutations affect the response to crizotinib.

Methods: We analyzed preclinical models of ALK rearranged lung cancers that were sensitive/resistant to ALK inhibitors, probed our institutional and other lung cancer databases for tumors with ALK kinase domain mutations, and evaluated tumor response to crizotinib.

Results: ALK rearranged cell lines with ALK kinase domain mutations were heterogeneously less inhibited by increasing concentrations of crizotinib than cells driven solely by EML4-ALK fusions. Previous ALK rearranged lung cancer cohorts did not report ALK kinase mutations in inhibitor-naïve tumors. We identified one TKI-naïve ALK rearranged tumor with an ALK kinase domain mutation: ALK-S1206F (mutations at ALK-S1206 shifted crizotinib inhibitory curves only minimally in preclinical models). The never smoker whose tumor harbored de novo EML4-ALK-E5;A20+ALK-S1206F only achieved a 4-month radiographic response to crizotinib 250mg twice daily.

Conclusions: Combining data from our and prior cohorts, ALK kinase domain mutations were uncommon events (<3% of cases) in ALK inhibitor-naïve ALK rearranged lung adenocarcinomas but their effect on intrinsic resistance to ALK inhibitors should be better evaluated.

Keywords: ALK; Adenocarcinoma; Crizotinib; Kinase domain; Lung cancer; Mutation.

MeSH terms

  • Adenocarcinoma / drug therapy
  • Adenocarcinoma / genetics
  • Adenocarcinoma of Lung
  • Anaplastic Lymphoma Kinase
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Cell Line, Tumor
  • Crizotinib
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm / genetics
  • Gene Rearrangement*
  • Humans
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / genetics*
  • Mutation*
  • Oncogene Proteins, Fusion / genetics
  • Protein Interaction Domains and Motifs / genetics*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use
  • Pyridines / pharmacology
  • Pyridines / therapeutic use
  • Receptor Protein-Tyrosine Kinases / chemistry
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Treatment Outcome

Substances

  • Oncogene Proteins, Fusion
  • Protein Kinase Inhibitors
  • Pyrazoles
  • Pyridines
  • Crizotinib
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Receptor Protein-Tyrosine Kinases