Longer OS with atezolizumab + carboplatin + nab-paclitaxel in advanced squamous NSCLC

The IMpower 131 study assessed atezolizumab + chemotherapy vs chemotherapy alone as first-line therapy in patients with stage IV squamous NSCLC. The final results showed that patients treated with atezolizumab + chemotherapy experienced a longer survival, as compared to those treated with chemotherapy alone. Meaningful survival difference was seen in patients with strongly PD-L1-positive tumours.

A total of 1,021 patients was enrolled in the study and they were divided between 3 arms. Patients in Arm A received atezolizumab + carboplatin+ paclitaxel (4 or 6 cycles), patients in Arm B were treated with atezolizumab + carboplatin + nab-paclitaxel (4 or 6 cycles) and those in Arm C (control group) were treated with carboplatin + nab-paclitaxel (4 or 6 cycles, followed by best supportive care). Median follow-up was 25.5 months.

The results showed that the final overall survival in the intention-to-treat population (Arm B vs Arm C) was 14.2 months in Arm B and 13.5 months in Arm C (HR 0.88; 95% CI 0.73-1.05; P=0.1581; see Figure) [1]. Patients who had high PD-L1 expression had a median OS of 23.4 months in Arm B and 10.2 months in Arm C. Treatment-related adverse events occurred in 68.0% (Arm B) and 57.5% (Arm C) of patients; no new safety signals were identified, which was consistent with previous analyses.

Figure. Final overall survival outcomes in intention-to-treat population (Arm B vs Arm C) [1]



The authors concluded that IMpower 131 provides additional evidence on the efficacy of immunotherapy in patients with squamous NSCLC. However, the observed benefit was only significant in high PD-L1 expressors, which highlights the relevance of biomarkers for patient selection in the study’s setting [1].

1.  Capuzzo F, et al. OA14.02. WCLC 2019.

Posted on 8 November 201916 February 2024