Bayesian meta-analysis of immunotherapy for head and neck squamous cell carcinoma with PD-L1 combined positive score less than 1

Immune checkpoint inhibitors (ICIs) are recommended for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC), including patients with tumors with a PD-L1 combined positive score (CPS) less than 1. A bayesian meta-analysis of phase 3 randomized trials comparing ICI-based regimens versus standard non-ICI control in HNSCC was carried out to quantify the probability that ICIs are associated with improved of reduced survival in HNSCC with CPS less than 1. The meta-analysis included 7 trials from 2018 to 2025, involving 630 patients with tumors with a PD-L1 CPS less than 1. Bayesian methods demonstrated that ICIs were associated with high probability of reduced survival in this patient population, both in recurrent/metastatic and locally advanced settings. For recurrent/metastatic disease, frequentist methods confirmed a significant association with reduced overall survival. The authors conclude that these findings reveal a consistent signal of reduced survival with ICIs among patients with HNSCC with a PD-L1 CPS less than 1.