Comparison of clinical outcomes of osimertinib and first-generation EGFR-tyrosine kinase inhibitors (TKIs) in TKI-untreated EGFR-mutated non-small-cell lung cancer with leptomeningeal metastases

ESMO Open. 2023 Aug;8(4):101594. doi: 10.1016/j.esmoop.2023.101594. Epub 2023 Jul 28.

Abstract

Background: Leptomeningeal metastases (LM) are devastating complications of epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC). Although osimertinib, a third-generation EGFR-tyrosine kinase inhibitor (TKI), has better penetration into the central nervous system than first-generation EGFR-TKIs, data on the distinct activity of EGFR-TKIs in untreated advanced EGFR-mutated NSCLC with LM are lacking.

Patients and methods: We retrospectively reviewed patients treated with EGFR-TKIs for TKI-untreated common EGFR-mutated NSCLC with LM between July 2002 and July 2021 at the National Cancer Center Hospital. The patients were divided into two groups: patients treated with osimertinib (Osi group) and those treated with gefitinib or erlotinib [first-generation (1G)-TKI group].

Results: Of the 967 patients, 71 were eligible, including 29 in the Osi group and 42 in the 1G-TKI group. The median progression-free survival (PFS) and overall survival (OS) in the Osi group were better than those in the 1G-TKI group (PFS: 16.9 months versus 8.6 months, P = 0.007, and OS: 26.6 months versus 20.0 months, P = 0.158). The LM-overall response rate (ORR) and LM-PFS were significantly better in the Osi group than in the 1G-TKI group (LM-ORR: 62.5% versus 25.7%, P = 0.007; LM-PFS: 23.4 months versus 12.1 months, P = 0.021). In the subgroup analysis of EGFR mutation status, LM-PFS for patients with exon 19 deletion was significantly longer in the Osi group than in the 1G-TKI group (32.7 months versus 13.4 months, P = 0.013), whereas those with L858R mutation in exon 21 did not differ between the two groups. In the multivariate analysis, osimertinib and exon 19 deletion were significant factors for better LM-PFS and OS.

Conclusion: Osimertinib can be more effective for untreated common EGFR-mutated NSCLC patients with LM, especially those with exon 19 deletion, compared to first-generation TKIs.

Keywords: erlotinib; gefitinib; leptomeningeal metastases; non-small-cell lung cancer; osimertinib.

Publication types

  • Comparative Study

MeSH terms

  • Carcinoma, Non-Small-Cell Lung* / drug therapy
  • Carcinoma, Non-Small-Cell Lung* / genetics
  • Carcinoma, Non-Small-Cell Lung* / pathology
  • ErbB Receptors / genetics
  • Humans
  • Lung Neoplasms* / drug therapy
  • Lung Neoplasms* / genetics
  • Lung Neoplasms* / pathology
  • Protein Kinase Inhibitors / therapeutic use
  • Retrospective Studies
  • Tyrosine Kinase Inhibitors

Substances

  • EGFR protein, human
  • ErbB Receptors
  • osimertinib
  • Protein Kinase Inhibitors
  • Tyrosine Kinase Inhibitors