First-line treatment with irreversible tyrosine kinase inhibitors associated with longer OS in EGFR mutation-positive non-small cell lung cancer.

Background: Few studies have compared the efficacy of the irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), afatinib, with that of reversible EGFR-TKIs. Therefore, this study assessed the effectiveness of afatinib, erlotinib, and gefitinib in terms of OS (overall survival) and progression-free survival (PFS) in EGFR mutation-positive advanced non-small cell lung cancer (NSCLC) patients.

Methods: Patients with EGFR mutation-positive advanced NSCLC who sought treatment from December 2013 to June 2018, at a tertiary referral center were retrospectively analyzed. These patients were treated with afatinib or a reversible EGFR-TKI (erlotinib or gefitinib) until disease progression, intolerable adverse events, or death. The Kaplan-Meier and log-rank tests were then used to compare the OS and PFS of the patients. We further analyzed the survival differences among the subgroup of patients without brain metastases.

Results: Of the 363 patients enrolled, 134 and 229 received first-line afatinib and first-line reversible EGFR-TKI, respectively. Those given afatinib had better OS (39.3 vs. 26.0 months; HR 0.65, P = 0.033) and PFS (14.1 vs.11.2 months; HR 0.58, P < 0.001). Of the 246 patients without brain metastases, 93 and 153 received first-line afatinib and a first-line reversible EGFR-TKI, respectively. Those given afatinib had a better OS (52.6 vs. 24.9 months; HR 0.62, P = 0.0030) and PFS (17.7 vs. 11.1 months; HR 0.51, P < 0.001). The survival benefit was more significant in the subgroup of patients with L858R substitutions.

Conclusions: The results indicated that afatnib resulted in significantly better OS and PFS than gefitnib and erlotinib for EGFR mutation-positive advanced NSCLC patients without brain metastases.

Key Points: Significant findings of the study Afatnib resulted in significantly better overall survival and progression-free survival than gefitnib and erlotinib for EGFR mutation-positive advanced non-small cell lung cancer patients without brain metastases. What this study adds This study helps fill the gap in our limited understanding of the differences in the efficacy of the irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), afatinib, with that of reversible EGFR-TKIs.