Prognostic immunoinflammatory and transcriptomic profiles in patients with pleural mesothelioma undergoing immunotherapy

Aim: A translational multiscale approach, encompassing tumor immune microenvironment (TIME), circulating immune-inflammatory benchmarks, and transcriptomic profiles, was undertaken to identify prognostic biomarkers of immunotherapy (IT) efficacy in patients with advanced pleural mesothelioma (PM). Methods: Advanced PM patients (n = 17) treated with nivolumab plus ipilimumab were prospectively enrolled in the FIL-QI 2021 study. Baseline blood and tumor samples were analyzed for immune subsets and functional markers (Granzyme B, Ki67) by flow cytometry, cytokines by multiplex ELISA, TILs and PD-L1 by immunohistochemistry, and gene expression by nanostring. Associations with overall survival (OS), progression-free survival (PFS), time-to-treatment failure (TTF), and modified disease control rate (mDCR) were assessed. Results: Higher baseline CD4+ GnzB+ T cells were significantly associated with OS ≥ 12 months (p < 0.001), PFS ≥ 6 months (p = 0.027), and TTF ≥ 6 months (p = 0.016), along with lower CD14+ monocytes (PFS: p = 0.038). Elevated proliferating CD8+ Ki67+ T cells (PFS: p = 0.038; TTF: p = 0.022) also predicted improved outcomes. Low IL-2 levels correlated with OS ≥ 12 months (p = 0.02). TIME analysis showed higher intratumor CD4+ TILs (p = 0.03) and CD4/CD8 ratio (p = 0.016) in long survivors. Transcriptomics revealed nine genes differentially regulated according to clinical outcomes, among which ULBP2 emerged as a strong predictor of poor prognosis (LASSO-Cox regression model). Conclusion: Parallel immune and transcriptomic profiling identifies biomarkers predictive of IT benefit in PM.