Osimertinib as first-line treatment for elderly patients with advanced EGFR mutation-positive non-small cell lung cancer in a real-world setting (OSI-FACT-EP)

Objectives: Osimertinib is the primary treatment for patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small cell lung cancer. However, evidence of the outcomes of osimertinib treatment in patients over 75 years of age in the real-world setting is limited. Materials and Methods: This retrospective study analyzed the data of 538 patients (203 elderly and 335 non-elderly) with EGFR mutation-positive lung cancer in whom osimertinib was initiated as first-line treatment between August 2018 and December 2019. Patients over 75 years of age were classified as elderly. The data cut-off date was February 28, 2022. Results: The progression-free survival (PFS) did not significantly differ between the elderly and non-elderly groups [elderly group: median PFS, 16.9 months (95 % confidence interval (CI), 14.3–20.2); non-elderly group: median PFS, 22.1 months (95 % CI: 19.5–26.3); hazard ratio (HR) for the elderly against the non-elderly: 1.21 (95 % CI: 0.98–1.50), p = 0.079]. However, the time to treatment failure (TTF) was significantly shorter in the elderly than in the non-elderly [elderly group: median TTF, 14.0 months (95 % CI: 0.98–1.50); non-elderly group: median TTF, 21.8 months (95 % CI: 18.2–24.6); HR for the elderly against the non-elderly: 1.46 (95 % CI: 1.20–1.77), p < 0.001]. Furthermore, the rate of treatment discontinuation because of adverse events was 28.6 % in the elderly and 14.9 % in the non-elderly (p < 0.001). Among patients who discontinued treatment, the conversion rate to second-line treatment was 39.6 % in the elderly and 72.8 % in the non-elderly. In addition, the median overall survival was 30 months (95 % CI: 25.8–37.7) in the elderly and not reached (NR) (95 % CI: NR–NR) in the non-elderly (p < 0.001). Conclusion: In a real-world clinical setting, elderly patients receiving osimertinib as first-line treatment should be aware of the frequent inability to transition to second-line treatment due to adverse events.