Final Overall Survival With Atezolizumab/Chemotherapy in Advanced Lung Cancer
Posted: Wednesday, November 27, 2019
According to the final overall survival results of the IMpower131 trial presented at the International Association for the Study of Lung Cancer (IASLC) 2019 World Conference on Lung Cancer (WCLC) in Barcelona (Abstract OA14.02), no meaningful difference in overall survival was observed between patients with advanced squamous non–small cell lung cancer (NSCLC) treated with atezolizumab plus chemotherapy versus those treated with chemotherapy alone. In addition, no unexpected safety signals were reported.
“The study provides additional evidence on the efficacy of immunotherapy in patients with lung cancer,” stated Federico Cappuzzo, MD, PhD, of the Azienda UNITA Sanitarian Locale Della Romagna, Italy, in an IASLC press release. “The strong benefit observed in high PD-L1 expressors highlights the relevance of biomarkers for patient selection.”
The IMpower131 trial enrolled 1,021 patients with stage IV squamous NSCLC. Patients were randomly assigned to receive atezolizumab plus carboplatin and paclitaxel every 3 weeks (arm A), atezolizumab plus carboplatin and nab-paclitaxel every week (arm B), or carboplatin plus nab-paclitaxel every week (arm C). This analysis reported only on arm B versus arm C.
A total of 343 patients in arm B and 340 patients in arm C were evaluated. PD-L1 expression was comparable between both groups, with high expression in 14% of those in arm B, positive expression in 39%, and negative expression in 47%, whereas the rates were 13% high, 37% positive, and 50% negative in arm C. Among patients in the intention-to-treat analysis, median overall survival was 14.2 months for arm B versus 13.5 months for arm C, which was not a statistically significant difference. However, in the PD-L1–high subgroup, there was a large gap in median overall survival—23.4 months for arm B versus 10.2 months for arm C.
The safety profile of the treatments coincided with expected results. Arm B experienced treatment-related grade 3 or 4 adverse events in 68% of patients and treatment-related serious adverse events in 21% of patients. As for arm C, such events were recorded in 57.5% and 10.5% of patients, respectively.
Disclosure: The study authors’ disclosure information may be found at wclc2019.iaslc.org.