Patients with stage IV squamous non–small cell lung cancer (NSCLC) with high programmed cell death ligand 1 (PD-L1) expression treated with atezolizumab and chemotherapy experienced longer overall survival rates than those treated with chemotherapy alone. The data from the IMpower131 trial were presented by Federico Cappuzzo, MD, of Azienda Unità Sanitaria Locale della Romagna at the International Association for the Study of Lung Cancer (IASLC) 2019 World Conference on Lung Cancer (WCLC) (Abstract OA14.02).
“The study provides additional evidence on the efficacy of immunotherapy in patients with lung cancer. The strong benefit observed in high PD-L1 expressors highlights relevance of biomarkers for patient selection.”— Federico Cappuzzo, MD
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IMpower 131
IMpower131 is a randomized phase III trial of atezolizumab plus chemotherapy vs chemotherapy alone as first-line therapy in stage IV squamous NSCLC. The multicenter trial enrolled 1.021 patients. The 343 patients in arm B received atezolizumab/carboplatin/nab-paclitaxel 100 mg/m2 once a week. The 340 patients enrolled in arm C received carboplatin/nab-paclitaxel for four or six cycles, followed by best supportive care. The proportion of patients with high positive or negative PD-L1 expression was similar between arms.
Results
Median overall survival in the intention-to-treat population was 14.2 months in arm B vs 13.5 months in arm C, not crossing the boundary for statistical significance. In the PD-L1–high subgroup, median overall survival was 23.4 vs 10.2 months, respectively.
Treatment-related grade 3-4 adverse events and treatment-related adverse effects occurred in 68.0% and 21.0% (arm B) and 57.5% and 10.5% (arm C) of patients; no new safety signals were identified—consistent with previous analyses.
Final overall survival in arm B vs C did not cross the boundary for statistical significance, but clinically meaningful overall survival improvement was observed in the PD-L1–high subgroup, despite not being formally tested.
“The study provides additional evidence on the efficacy of immunotherapy in patients with lung cancer. The strong benefit observed in high PD-L1 expressors highlights relevance of biomarkers for patient selection,” said Dr. Cappuzzo in a press release.
Disclosure: For full disclosures of the study authors, visit wclc2019.iaslc.org.
