PD-L1

This study identifies ERO1A as a novel and promising biomarker for early-stage lung adenocarcinoma (esLUAD). High ERO1A expression is associated with poor prognosis, yet paradoxically, it correlates with an immune-activated tumor microenvironment. Tumors with elevated ERO1A levels demonstrate a superior response to immune checkpoint inhibitors. This biomarker could therefore aid in patient stratification and guide peri-operative therapeutic decisions.

This phase 2 study investigated the efficacy of pembrolizumab in 154 patients with advanced rare cancers, conditions often lacking established treatment options. The findings demonstrated an objective response rate of 14.8% and a clinical benefit rate of 26.8%. Multi-modal analysis revealed an association between clinical benefit and biomarkers such as high microsatellite instability (MSI-H), high tumor mutation burden (TMB-H), and a PD-L1 combined positive score (CPS) ≥10. The study also highlighted features of the tumor immune microenvironment, such as increased immune infiltration and T cell activation prior to treatment, as potential predictive markers.