OBJECTIVES: Both afatinib and osimertinib are approval for first-line treatment of non–small-cell lung cancer (NSCLC) among the patients with epidermal growth factor receptor (EGFR) exon 19 deletion (E19del). However, real-world evidence of head-to-head comparison of these agents remains limited. Our study was aimed to evaluate osimertinib and afatinib as first-line therapy for NSCLC patients.

METHODS: We conducted a retrospectively cohort study with historical control design by using a multi-institutional electronic database in Taiwan. Patients with advanced NSCLC and EGFR E19del were enrolled. We included patients who newly used osimertinib between April 2020 to December 2021. We defined afatinib new users between May 2018 to December 2019 as historical group. We extracted electronic medical records to confirm disease status. Each patient followed up to death, loss of follow-up or maximum time of two years. Inverse probability of treatment weighting (IPTW) method was applied to ensure two groups comparability. Effectiveness outcomes include progress-free survival (PFS) and overall survival (OS). Time-varying Cox regression model was applied to estimate adjusted hazard ratio (aHR) between osimertinib and afatinib users.

RESULTS: A total of 69 osimertinib and 96 afatinib new users were included. All baseline characteristics, including sex, disease status and performance status, were similar between two groups, except for age (median: 60.0 vs. 67.0 years, P value < 0.01). Unadjusted median PFS was 15 and 17.5 months in afatinib and osimertinib groups, respectively. After IPTW, adjusted hazard ratio of PFS and OS were 0.86 (0.64-1.17) and 0.93 (0.63-1.38), respectively.

CONCLUSIONS: According to our real-world data, osimertinib and afatinib showed similar clinical effectiveness. But it still need a longer observation to support our research findings.