Erlotinib at a dose of 25 mg daily for non-small cell lung cancers with EGFR mutations

J Thorac Oncol. 2010 Jul;5(7):1048-53. doi: 10.1097/JTO.0b013e3181dd1386.


Purpose: The tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are effective in non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) gene mutations. The usual clinical dose of gefitinib (250 mg/d) is only one third of its maximum tolerated dose, whereas the dose of erlotinib (150 mg/d) is at its maximum tolerated dose. In NSCLC cell lines, both TKIs have similar micromolar inhibitory concentrations. We explored whether erlotinib at 25 mg/d (trough serum concentration similar to gefitinib 250 mg/d) would be efficacious in EGFR-mutated NSCLC.

Methods: To study the inhibitory concentrations of gefitinib and erlotinib, we exposed EGFR-mutated cell lines (HCC827, H3255, PC-9, and H1975) to increasing concentrations of these TKIs. Further on, we performed a retrospective evaluation of seven patients with advanced EGFR-mutated (exon 19 deletions and L858R) NSCLC that were given erlotinib at 25 mg/d as their first EGFR TKI.

Results: Gefitinib and erlotinib generated similar inhibitory curves across our panel of EGFR-mutated NSCLC cell lines with overlapping mean 50% inhibitory concentration 95% confidence intervals for HCC827, PC-9, and H1975. Both drugs also displayed a high degree of correlation in mean 50% inhibitory concentration (Pearson's r = 0.99, p = 0.0417). Of the seven patients, five patients (71.5%) had partial responses to erlotinib 25 mg/d. Median progression-free survival was 17 months (95% confidence interval, 6-35 months). Toxicities were minimal, with only two (28.5%) patients having a rash and none experiencing (0%) diarrhea.

Conclusions: In NSCLC cell lines, gefitinib and erlotinib have similar inhibitory profiles. In patients with NSCLC and EGFR-activating mutations, a dose of erlotinib 25 mg/d (equivalent to gefitinib 250 mg/d) leads to impressive response rates and progression-free survival similar to the growing experience with the approved doses of gefitinib (250 mg/d) and erlotinib (150 mg/d). Identifying prospectively the lowest and clinically active dose ranges of erlotinib and gefitinib will help further to personalize care for patients with tumors harboring EGFR mutations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Aged
  • Aged, 80 and over
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Proliferation / drug effects
  • ErbB Receptors / genetics*
  • Erlotinib Hydrochloride
  • Female
  • Gefitinib
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / pathology
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Quinazolines / administration & dosage
  • Retrospective Studies
  • Survival Rate
  • Treatment Outcome
  • Tumor Cells, Cultured


  • Quinazolines
  • Erlotinib Hydrochloride
  • EGFR protein, human
  • ErbB Receptors
  • Gefitinib