Checkpoint Inhibitors in Metastatic EGFR-Mutated Non-Small Cell Lung Cancer A Meta-Analysis

Introduction: We performed a meta-analysis to assess the role of immune checkpoint inhibitors as second-line therapy in EGFR-mutant advanced NSCLC. Methods: Randomized trials comparing immune checkpoint inhibitors against chemotherapy were identified. We retrieved the hazard ratio (HR) and 95% confidence interval (CI) for overall survival (OS) of the intention-to-treat population and EGFR mutation-defined subgroups. We used the fixed-effects inverse variance-weighted method to pool estimates of treatment efficacy. Statistical tests were two sided. Results: In the three included studies that compared immune checkpoint inhibitors (nivolumab [n = 292], pembrolizumab = 691], and atezolizumab [n =144]) against docetaxel (n = 776), immune checkpoint inhibitors significantly prolonged OS over that with docetaxel overall (n = 1903, HR = 0.68, 95% CI: 0.61-0.77, p < 0.0001) and in the EGFR wild-type subgroup (n = 1362, HR = 0.66, 95% CI: 0.58-0.76, p < 0.0001) but not in the EGFR-mutant subgroup (n = 186, HR = 1.05, 95% CI: 0.70-1.55, p < 0.81; treatment-mutation interaction p = 0.03). Conclusion: In EGFR-mutant advanced NSCLC, immune checkpoint inhibitors do not improve OS over that with docetaxel. Mechanisms of acquired resistance to first-line tyrosine kinase inhibitor therapy should be elucidated to guide selection of second-line treatment for these patients. (C) 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.