Updated Overall Survival Analysis From IMpower110: Atezolizumab Versus Platinum-Based Chemotherapy in Treatment-Naive Programmed Death-Ligand 1-Selected NSCLC

Introduction: IMpower110 previously revealed significant overall survival (OS) benefit with atezolizumab versus chemotherapy in patients with treatment-naive EGFR-and ALK-negative (wild type [WT]) metastatic NSCLC with high programmed death-ligand 1 (PD-L1) expression (>50% on tumor cells [TCs] or >10% on tumor-infiltrating immune cells [ICs], per SP142 immunohistochemistry assay; p = 0.0106). We present primary OS analyses in lower PD-L1 expression groups and an updated, exploratory analysis in the high PD-L1 expression group. Methods: This open-label, phase 3 trial randomized patients with PD-L1 expression on greater than or equal to 1% of TC or IC to receive atezolizumab or platinum-based chemotherapy. The primary end point was OS, hierarchically tested in PD-L1 expression WT subgroups: first the high PD-L1 expression subgroup, then the high-or intermediate PD-L1 expression subgroup (>5% on TC or IC), and then the any PD-L1 expression subgroup (>1% on TC or IC). Results: The any PD-L1 expression WT population included 554 patients (excluded 18 EGFR-or ALK-positive patients). With 17 months' additional follow-up, OS improvement in the atezolizumab versus chemotherapy arm was not statistically significant in high-or-intermediate PD-L1 expression WT patients (n = 328; hazard ratio = 0.87, 95% confidence interval: 0.66-1.14, p = 0.3091; median = 19.9 versus 16.1 mo), precluding formal OS testing in any PD-L1 expression WT patients. Exploratory analysis in high PD-L1 expression WT patients (n = 205) revealed maintained OS benefit in the atezolizumab arm (hazard ratio = 0.76, 95% confidence interval: 0.54-1.09; median = 20.2 versus 14.7 mo). Updated safety data continued to favor atezolizumab. Conclusions: Statistical significance for OS was not revealed in the high-or-intermediate expression WT group, and, as a result, OS in the any PD-L1 expression WT group was not formally tested. No new safety signals were found. This updated analysis of IMpower110 supports using atezolizumab in treatment-naive, metastatic WT NSCLC with high PD-L1 expression. (c) 2021 Published by Elsevier Inc. on behalf of International Association for the Study of Lung Cancer.

Automated summary

The study demonstrated that atezolizumab did not show significant OS benefit compared to chemotherapy in NSCLC patients with lower PD-L1 expression levels, while maintaining OS benefit in patients with higher PD-L1 expression levels. Safety data continued to support the use of atezolizumab.