An Anti-VEGF-B Antibody Reduces Abnormal Tumor Vasculature and Enhances the Effects of Chemotherapy.

Simple Summary: In order to grow, tumors need nutrients and oxygen, which are supplied by new blood vessels that are often abnormal and leaky. The development of these blood vessels is driven by proteins called growth factors, which bind to receptor proteins on other cells. We show for the first time that an antibody against a vascular growth factor called VEGF-B, when used to treat mice with tumors, reduces the amount of abnormal tumor blood vessels, and inhibits tumor growth, as well as improving the response to chemotherapy. These results suggest that targeting VEGF-B could be a potential approach for anti-cancer therapy, particularly in combination with chemotherapy. The vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key regulators of blood vessel formation, including in tumors, where their deregulated function can promote the production of aberrant, leaky blood vessels, supporting tumor development. Here we investigated the VEGFR1 ligand VEGF-B, which we demonstrate to be expressed in tumor cells and in tumor stroma and vasculature across a range of tumor types. We examined the anti-VEGF-B-specific monoclonal antibody 2H10 in preclinical xenograft models of breast and colorectal cancer, in comparison with the anti-VEGF-A antibody bevacizumab. Similar to bevacizumab, 2H10 therapy was associated with changes in tumor blood vessels and intra-tumoral diffusion consistent with normalization of the tumor vasculature. Accordingly, treatment resulted in partial inhibition of tumor growth, and significantly improved the response to chemotherapy. Our studies indicate the importance of VEGF-B in tumor growth, and the potential of specific anti-VEGF-B treatment to inhibit tumor development, alone or in combination with established chemotherapies. [ABSTRACT FROM AUTHOR]