The best regimens for chemo-naïve incurable non-squamous non-small cell lung cancer with a programmed death-ligand 1, tumor proportion score 1–49%: a network meta-analysis

BACKGROUND: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. There is a rank order of the efficacy and safety of treatment options, including immune checkpoint inhibitors (ICIs), bevacizumab (Bev), and cytotoxic drugs. When patients have low programmed death-ligand 1 (PD-L1) expression, there are multiple options for treatment. In this study, we focused on ICI regimens in patients with non-squamous NSCLC with low PD-L1 expression and no driver alterations and assessed the efficacy of the regimens using network meta-analysis. METHODS: Randomized trials for incurable chemo-naïve non-squamous NSCLC were collected through electronic searches. The data were independently extracted and cross-checked by two investigators. The primary outcome of this analysis was overall survival (OS). A frequentist weighted least-squares approach random-model network meta-analysis was applied. RESULTS: Sixty-eight eligible studies and 22,619 patients were identified. Using a platinum + third-generation cytotoxic agent regimen (platinum regimen) as a reference, the platinum regimen + pembrolizumab (Pemb) [hazard ratio (HR) =0.55, 95% confidence interval (CI): 0.34–0.89, P=0.015] showed the best OS, followed by the platinum regimen + nivolumab (Niv) + ipilimumab (Ipi) (HR =0.61, 95% CI: 0.44–0.84, P=0.003) with no heterogeneity (I(2)=0%, P=0.348). CONCLUSIONS: The addition of Pemb or Niv/Ipi to platinum-based chemotherapy seems to be a good therapeutic option for non-squamous NSCLC with a PD-L1 tumor proportion score (TPS) of 1–49%.