The Difference in Clinical Outcomes Between Osimertinib and Afatinib for First-Line Treatment in Patients with Advanced and Recurrent EGFR-Mutant Non-Small Cell Lung Cancer in Taiwan

BACKGROUND: Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors are the standard first-line treatment for patients with advanced and recurrent EGFR-positive non-small cell lung cancer. OBJECTIVE: The main objective of the present study was to compare the clinical efficacies between osimertinib and afatinib as first-line treatment in patients with EGFR-mutant non-small cell lung cancer. METHODS: We retrospectively analyzed patients with advanced and recurrent non-small cell lung cancer who harbored an exon 19 deletion or an exon 21 L858R mutation and were being given either osimertinib or afatinib as first-line treatment from January 2018 to December 2020. RESULTS: A total of 128 patients were selected for this study. The osimertinib group included 47 patients, while 81 patients received afatinib. The median follow-up time was 20.1 months in the osimertinib group and 22.7 months in the afatinib group. The median progression-free survival was 18.8 months and 13.1 months in the osimertinib and afatinib groups, respectively (hazard ratio 0.75 [95% confidence interval 0.48–1.18]). The median overall survival was not reached in the osimertinib group and was 41.7 months in the afatinib group (hazard ratio 0.79 [95% confidence interval 0.36–1.72]). In patients without brain metastasis, the median progression-free survival was 17.9 months and 17.2 months in the osimertinib and afatinib groups, respectively (hazard ratio 1.02 [95% confidence interval 0.56–1.85]). In patients with brain metastasis at baseline, the median progression-free survival was 22.1 months in the osimertinib group, and 10.9 months in the afatinib group (adjusted hazard ratio 0.45 [95% confidence interval 0.21–0.96]). CONCLUSIONS: Our research demonstrates that there was no strong evidence showing that patients taking osimertinib as first-line treatment experienced longer median progression-free survival and overall survival than patients treated with afatinib. However, there was a statistical significance revealing that osimertinib provided better median progression-free survival than afatinib in patients with brain metastasis at baseline.