Efficacy and safety findings of the EXTRA study in older adult EGFR-mutant lung cancer patients receiving afatinib as first-line treatment.

The EXTRA trial was the first to identify predictive biomarkers for afatinib efficacy in epidermal growth factor receptor (EGFR)-mutant NSCLC. We analyzed the clinical data of older adult patients before translational analysis. This prospective study involved untreated patients with EGFR-mutant NSCLC who received afatinib at an initial dose of 40 mg/day, followed by stepwise dose reductions, ultimately reaching 20 mg administered every other day. Treatment efficacy and adverse events (AEs) were compared between non-older and older adult patients. Among the 103 patients, 71 were aged < 75 years, and 32 were aged ≥ 75 years. Despite increased dose reductions in the older adults, progression-free survival was comparable: 21.5 vs. 18.6 months for non-older and older adults, respectively. The median overall survival (OS) was not reached in either group; the 2-year OS rates were 82% and 75% in non-older and older adults, respectively. Median post-progression survival in patients administered second-line drug therapy was 14.3 and 11.2 months in non-older (n = 42) and older adults (n = 20), respectively. Among older adults, 31 (97%) patients experienced AEs of all grades, and only six patients had grade ≥ 3 AEs with no grade 5 AEs. Afatinib demonstrated comparable therapeutic efficacy and safety in older and non-older adult patients with advanced EGFR-mutant NSCLC.Trial registration: UMIN-CTR identifier (UMIN000024935).