Best regimens for treating chemo-naïve incurable squamous non-small cell lung cancer with a programmed death-ligand 1 tumor proportion score of 1%-49%: A network meta-analysis

Background: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. It is advisable to select the appropriate treatment based on characteristics of the cancer such as pathology, mutations, and programmed death-ligand 1 (PD-L1) levels. In this study, by remarking squamous NSCLC with low PD-L1 expression without mutations, we investigated the efficacy and safety of regimens that included molecularly targeted drugs such as immune checkpoint inhibitors (ICIs) through a network meta-analysis.

Methods: Databases were searched systematically to identify appropriate articles, in which randomized trials with incurable squamous NSCLC were described. Suitable studies were manually checked by two reviewers. A random model network meta-analysis was conducted, in which the primary outcome was the overall survival rate.

Results: We identified 48 studies, which included 16 391 patients. When a platinum + third-generation cytotoxic agent regimen (platinum regimen) was a reference, the platinum regimen + pembrolizumab (Pemb) yielded the best results in regard to the overall survival rate when compared with chemotherapy (hazard ratio [HR] = 0.57, 95% confidence interval [CI] = 0.36-0.90, p = 0.016) followed by the platinum regimen + nivolumab (Niv) + ipilimumab (Ipi) (HR = 0.61, 95% CI = 0.44-0.84, p = 0.003). However, the efficacy of ICI monotherapy was not statistically different from that of the platinum regimen.

Conclusions: The combination therapies, which were the platinum regimen + Pemb and the platinum regimen + Niv + Ipi, rather than ICI monotherapy were effective first-line agents for treating squamous NSCLC with low PD-L1 levels.