Final overall survival results of carboplatin + nab-paclitaxel ± atezolizumab in advanced squamous NSCLC

Patients with Stage IV squamous non-small cell lung cancer enrolled in clinical trial to test the immunotherapy atezolizumab and chemotherapy against chemotherapy alone experienced a longer survival rate, among a subgroup of patients with high PD-LI.

The data for the Impower131 Trial was presented today by Dr. F. Cappuzzo, from Azienda Unità Sanitaria Locale della Romagna, Ravenna/Italy at the IASLC 2019 World Conference on Lung Cancer, hosted by the International Association for the Study of Lung Cancer.

IMpower131 is a randomized Phase III trial of atezolizumab + chemotherapy vs chemotherapy alone as first-line therapy in Stage IV squamous NSCLC, which is the most advanced form of the disease. The five-year survival rate for those diagnosed with stage IV lung cancer is less than 10 percent.

The multi-center trial enrolled 1021 patients— the 343 patients in Arm B received atezolizumab + carboplatin + nab-paclitaxel 100 mg/m2 qw. There were 340 patients enrolled in Arm C who 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. 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 AEs 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," Dr. Cappuzzo said.