Diverse Resistance Mechanisms to the Third-Generation ALK Inhibitor Lorlatinib in ALK-Rearranged Lung Cancer

Clin Cancer Res. 2020 Jan 1;26(1):242-255. doi: 10.1158/1078-0432.CCR-19-1104. Epub 2019 Oct 4.


Purpose: Lorlatinib is a third-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor with proven efficacy in patients with ALK-rearranged lung cancer previously treated with first- and second-generation ALK inhibitors. Beside compound mutations in the ALK kinase domain, other resistance mechanisms driving lorlatinib resistance remain unknown. We aimed to characterize the mechanisms of resistance to lorlatinib occurring in patients with ALK-rearranged lung cancer and design new therapeutic strategies in this setting.

Experimental design: Resistance mechanisms were investigated in 5 patients resistant to lorlatinib. Longitudinal tumor biopsies were studied using high-throughput next-generation sequencing. Patient-derived models were developed to characterize the acquired resistance mechanisms, and Ba/F3 cell mutants were generated to study the effect of novel ALK compound mutations. Drug combinatory strategies were evaluated in vitro and in vivo to overcome lorlatinib resistance.

Results: Diverse biological mechanisms leading to lorlatinib resistance were identified. Epithelial-mesenchymal transition (EMT) mediated resistance in two patient-derived cell lines and was susceptible to dual SRC and ALK inhibition. We characterized three ALK kinase domain compound mutations occurring in patients, L1196M/D1203N, F1174L/G1202R, and C1156Y/G1269A, with differential susceptibility to ALK inhibition by lorlatinib. We identified a novel bypass mechanism of resistance caused by NF2 loss-of-function mutations, conferring sensitivity to treatment with mTOR inhibitors.

Conclusions: This study shows that mechanisms of resistance to lorlatinib are diverse and complex, requiring new therapeutic strategies to tailor treatment upon disease progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aminopyridines
  • Anaplastic Lymphoma Kinase / antagonists & inhibitors*
  • Anaplastic Lymphoma Kinase / genetics*
  • Animals
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm
  • Epithelial-Mesenchymal Transition
  • Female
  • Gene Rearrangement
  • Humans
  • Lactams
  • Lactams, Macrocyclic / pharmacology*
  • Lactams, Macrocyclic / therapeutic use
  • Longitudinal Studies
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / pathology
  • Male
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Middle Aged
  • Mutation
  • Neurofibromin 2 / genetics
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Pyrazoles
  • Xenograft Model Antitumor Assays


  • Aminopyridines
  • Lactams
  • Lactams, Macrocyclic
  • NF2 protein, human
  • Neurofibromin 2
  • Protein Kinase Inhibitors
  • Pyrazoles
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • lorlatinib