Comparison of efficacy of gefitinib and osimertinib for untreated EGFR mutation-positive non-small-cell lung cancer in patients with poor performance status

Background: There is a dearth of studies on the efficacy and safety of the tyrosine kinase inhibitors osimertinib (OSI) and gefitinib (GEF) in treating epidermal growth factor receptor ( EGFR ) mutation-positive non-small cell lung cancer (NSCLC), even in patients with poor performance status (PS). Methods: We retrospectively reviewed and compared data of 113 patients with EGFR mutation-positive NSCLC with Eastern Cooperative Oncology Group PS 2-4 who were administered OSI 80 mg/day or GEF 250 mg/day from May 2016 to March 2022. Results: The GEF group (39 patients; median age: 74 years) included 20 patients with a PS of 2, 17 with a PS of 3, and 2 with a PS of 4. The OSI group (74 patients; median age: 76 years) included 48 patients with a PS of 2, 24 with a PS of 3, and 2 with a PS of 4. The overall response rates were 69% and 66% in the GEF and OSI groups, respectively. The disease control and PS improvement rates were 89% and 51% in both groups, respectively. The median progression-free survival in the GEF and OSI groups was 6.9 and 9.2 months, respectively (p = 0.15). The OSI group experienced better overall survival than the GEF group (median: 20.9 vs. 13.0 months, p = 0.0031). The incidence of pneumonitis was 10% and 11% in the GEF and OSI groups, respectively. One treatment-related death owing to pneumonitis occurred in the GEF group. Conclusions: OSI may be a useful treatment for untreated EGFR mutation-positive NSCLC with poor PS.