Evidence for disease control with erlotinib after gefitinib failure in typical gefitinib-sensitive Asian patients with non-small cell lung cancer

Introduction: The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are gaining an increasing role in the management of advanced non-small cell lung cancer (NSCLC). There is mounting interest in the benefit of administering a second TKI after failure of the first TKI, especially in Asian patients, in whom they are expected to be more efficacious. Methods: We did a retrospective analysis of patients receiving both gefitinib and erlotinib in our institution during a 2-year period. Patients were to have received the second TKI after progressive disease on the first TKI. EGFR gene mutation analysis was done on patient tumor samples. Results: Fourteen patients were included in the analysis, all of whom received erlotinib after progression on gefitinib. Chinese race, females, never-smokers, and adenocarcinoma subtype were predominant in their respective categories. Disease control rate was 64.3% (9 of 14) for gefitinib. Disease control rate for erlotinib administered after progression on gefitinib was 35.7% (5 of 14). All patients who achieved disease control with erlotinib after progression on gefitinib were never-smokers with adenocarcinoma subtype, who had prior disease control on gefitinib. Presence of EGFR mutations predicted for disease control with gefitinib, and for disease control with erlotinib after gefitinib failure. Conclusion: A significant proportion of typical gefitinib-sensitive Asian NSCLC patients can have disease control with erlotinib after gefitinib failure. The role of subsequent administration of a second EGFR TKI after failure of the first TKI in advanced NSCLC should be further pursued.