Patients with non-small cell lung cancer (NSCLC) and high levels of PD-L1 expression derived significant benefit from first-line atezolizumab compared with platinum-based chemotherapy, according to interim results of the IMpower110 study presented at the the European Society for Medical Oncology (ESMO) Congress 2019.
The study included 572 chemotherapy-naive patients with stage IV NSCLC at PD-L1 expression of at least 1% on tumor cell (TC) or tumor-infiltrating immune cell (IC) staining. The patients were randomly assigned to receive atezolizumab or platinum-based chemotherapy.
The primary end point was overall survival tested hierarchically in wild-type patients classified by PD-L1 status on TC or IC. TC3 or IC3 was defined as PD-L1 expression of 50% or greater on TC and 10% or greater in IC (205 patients); TC2/3 was 5% or greater on TC and IC2/3 was 5% or greater in IC (328 patients); TC1/2/3 was 1% of greater and IC1/2/3 was 1% or greater (554 patients).
Among patients with the highest level of PD-L1 expression (TC3 and IC3), atezolizumab resulted in a 7.1-month improvement in median overall survival compared with chemotherapy (hazard ratio [HR], 0.595; P =.0106). Median overall survival was 20.2 months for atezolizumab and 13.1 months for chemotherapy.
Among patients classified at TC2/3 or IC2/3, the median overall survival for atezolizumab was 18.2 months compared with 14.9 months for chemotherapy (HR, 0.717; 95% CI, 0.520-0.989; P =.0416). No significant difference was found for the TC1/2/3 and IC1/2/3 groups.
Treatment-related adverse events occurred in 60.5% of patients assigned to receive atezolizumab and 85.2% of patients assigned to receive chemotherapy; grade 3/4 adverse events occurred in 12.9% of patients administered atezolizumab and 44.1% of patients administered chemotherapy.
Disclosure: This study was funded by F. Hoffman-LaRoche. For a full list of author disclosures, please refer to the abstract.
Spigel D, de Marinis F, Giaccone G, et al. Impower110: Interim overall survival (OS) analysis of a phase III study of atezolizumab (atezo) vs platinum-based chemotherapy (chemo) as first-line (1L) treatment (tx) in PD-L1–selected NSCLC. Presented at: European Society for Medical Oncology (ESMO) Congress 2019; September 27-October 1, 2019: Barcelona, Spain. Abstract LBA78.