[HTML][HTML] Atezolizumab in combination with bevacizumab enhances antigen-specific T-cell migration in metastatic renal cell carcinoma

JJ Wallin, JC Bendell, R Funke, M Sznol… - Nature …, 2016 - nature.com
JJ Wallin, JC Bendell, R Funke, M Sznol, K Korski, S Jones, G Hernandez, J Mier, X He
Nature communications, 2016nature.com
Anti-tumour immune activation by checkpoint inhibitors leads to durable responses in a
variety of cancers, but combination approaches are required to extend this benefit beyond a
subset of patients. In preclinical models tumour-derived VEGF limits immune cell activity
while anti-VEGF augments intra-tumoral T-cell infiltration, potentially through vascular
normalization and endothelial cell activation. This study investigates how VEGF blockade
with bevacizumab could potentiate PD-L1 checkpoint inhibition with atezolizumab in mRCC …
Abstract
Anti-tumour immune activation by checkpoint inhibitors leads to durable responses in a variety of cancers, but combination approaches are required to extend this benefit beyond a subset of patients. In preclinical models tumour-derived VEGF limits immune cell activity while anti-VEGF augments intra-tumoral T-cell infiltration, potentially through vascular normalization and endothelial cell activation. This study investigates how VEGF blockade with bevacizumab could potentiate PD-L1 checkpoint inhibition with atezolizumab in mRCC. Tissue collections are before treatment, after bevacizumab and after the addition of atezolizumab. We discover that intra-tumoral CD8+ T cells increase following combination treatment. A related increase is found in intra-tumoral MHC-I, Th1 and T-effector markers, and chemokines, most notably CX3CL1 (fractalkine). We also discover that the fractalkine receptor increases on peripheral CD8+ T cells with treatment. Furthermore, trafficking lymphocyte increases are observed in tumors following bevacizumab and combination treatment. These data suggest that the anti-VEGF and anti-PD-L1 combination improves antigen-specific T-cell migration.
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