High endothelial venules predict response to PD-1 inhibitors combined with anti-angiogenesis therapy in NSCLC

Tumor-associated high endothelial venules (TA-HEVs) mediate lymphocyte entry into tumors. Therefore, combined anti-angiogenesis therapy and programmed death-1 (PD-1) inhibitors might stimulate tumor immunity. This study will explore the TA-HEVs and real-world data of the combination therapy in non-small cell lung cancer (NSCLC). Firstly, we found a certain relationship between HEVs and immune effector cells by multiple immunofluorescence staining. We then analyzed the efficacy of immunotherapy combined with anti-angiogenesis therapy in advanced NSCLC patients by collecting real-world clinical data. Finally, we explored the predictive value of HEVs in combination therapy by analyzing pre-treatment pathological slides of patients with multiple immunofluorescence and RNA sequencing. Immunofluorescence staining of high endothelial venules (PNAd+) reveals that the frequency of HEVs is positively correlated with tumor-infiltrating stem-like CD8+ T cells (TCF-1+PD-1+) in the TME of advanced NSCLC patients (P = 0.0221). We retrospectively analyzed the efficacy of 96 patients with advanced NSCLC who received PD-1 inhibitors combined with anti-angiogenesis therapy in the real-world. The median PFS of patients combined with anti-angiogenesis therapy was longer than that of patients without anti-angiogenesis therapy (9.7 vs 8.6 months, P = 0.041). Multiple immunofluorescence staining of tumor biopsies before treatment from 14 patients with advanced NSCLC reveals that PNAd+ is predictive of better response and survival upon PD-1 inhibitors combined with anti-angiogenesis therapy (P = 0.0274). In addition, we collected peripheral blood from an effective group of patients for RNA sequencing and found that immune cells activation-related gene expression scores were higher. Combined anti-angiogenic and anti-PD-1 therapy stimulates tumor immunity through TA-HEVs formation. TA-HEVs not only mediate immune cell entry into tumors, but also are associated with the efficacy of PD-1 inhibitors and anti-angiogenesis therapy in NSCLC.