Atezolizumab in PD-L1–Selected Advanced Non–Small Cell Lung Cancer
The anti–PD-L1 monoclonal antibody atezolizumab may improve outcomes in patients who have programmed cell death ligand 1 (PD-L1) advanced non–small cell lung cancer (NSCLC), according to the results of the phase II BIRCH trial reported by Peters et al in the Journal of Clinical Oncology. Enriqueta Felip, MD, PhD, of Vall d’Hebron University Hospital, Barcelona Spain, corresponding author of this article, and colleagues conclude that “PD-L1 status may serve as a predictive biomarker for identifying patients most likely to benefit from atezolizumab.”
A total of 659 evaluable patients took part in the trial, and all had advanced NSCLC and no central nervous system metastases. Atezolizumab was given to 139 patients as first-line therapy (cohort 1), 268 patients as second-line therapy (cohort 2), and 252 patients as third-line or higher-line therapy (cohort 3). Only patients with PD-L1 expression ≥ 5% of tumor cells or tumor-infiltrating immune cells were enrolled. Expression levels ≥ 50% on tumor cells or ≥ 10% on tumor-infiltrating immune cells were defined as TC3 and IC3, respectively.
With a minimum of 12 months of follow-up, objective response rates were 22%, 19%, and 18% in cohorts 1, 2, and 3, respectively. In addition, the objective response rates in the TC3 or IC3 subgroups of the cohorts were 31%, 26%, and 27%, respectively.
With a minimum follow-up of 20 months, in the 3 cohorts, median overall survival was 23.5 months (26.9 months for TC3 or IC3 patients), 15.5 months (16.6 months for TC3 or IC3 patients), and 13.2 months (17.5 months for TC3 or IC3 patients).