Gefitinib does not provide a comparable improvement in progression-free survival to erlotinib in the treatment of patients with previously treated advanced lung adenocarcinoma, a study published in the Journal of Clinical Oncology has shown.1
Erlotinib and gefitinib are first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors indicated for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have EGFR exon 19 deletions or exon 21 substitution mutations. In this study, researchers sought to investigate the difference in outcomes, particularly progression-free survival, between these 2 EGFR kinase inhibitors.
For the phase 3 trial, researchers enrolled 561 previously treated patients with lung adenocarcinoma, of whom 401 had an EGFR mutation. Patients were randomly assigned to receive erlotinib or gefitinib.
Results showed that median progression-free survival was 6.5 months with gefitinib and 7.5 months with erlotinib (HR, 1.125; 95% CI: 0.940-1.347; P = .257). Median overall survival was 22.8 months and 24.5 months, respectively (HR, 1.038; 95% CI: 0.833-1.294; P = .768).
Furthermore, 45.9% of patients in the gefitinib arm achieved a response compared with 44.1% in the erlotinib arm.
Researchers found that among patients who were EGFR mutation-positive, median progression-free survival was 8.3 months with gefitinib vs 10.0 months with erlotinib (HR, 1.093; 95% CI: 0.879-1.358; P = .424).
In terms of safety, the most common grade 3 or 4 erlotinib-related adverse events was rash, while the most frequently reported grade 3 or 4 toxicity with gefitinib was alanine aminotransferase (ALT)/aspartate aminotransferase (AST) elevation.
The findings ultimately suggest that gefitinib is not noninferior to erlotinib in terms of progression-free survival in patients with lung adenocarcinoma.
1. Urata Y, Katakami N, Morita S, et al. Randomized phase III study comparing gefitinib with erlotinib in patients with previously treated advanced lung adenocarcinoma: WJOG 5108L [published online ahead of print March 28, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.63.4154.