Ang-2-VEGF-A CrossMab, a Novel Bispecific Human IgG1 Antibody Blocking VEGF-A and Ang-2 Functions Simultaneously, Mediates Potent Antitumor, Antiangiogenic, and Antimetastatic Efficacy

Abstract

VEGF-A blockade has been clinically validated as a treatment for human cancers. Angiopoietin-2 (Ang-2) expression has been shown to function as a key regulator of tumor angiogenesis and metastasis. We have applied the recently developed CrossMab technology for the generation of a bispecific antibody recognizing VEGF-A with one arm based on bevacizumab (Avastin), and the other arm recognizing Ang-2 based on LC06, an Ang-2 selective human IgG1 antibody. The potency of Ang-2-VEGF CrossMab was evaluated alone and in combination with chemotherapy using orthotopic and subcutaneous xenotransplantations, along with metastasis analysis by quantitative real-time Alu-PCR and ex vivo evaluation of vessels, hypoxia, proliferation, and apoptosis. The mechanism of action was further elucidated using Western blotting and ELISA assays. Ang-2-VEGF-A CrossMab showed potent tumor growth inhibition in a panel of orthotopic and subcutaneous syngeneic mouse tumors and patient or cell line-derived human tumor xenografts, especially at later stages of tumor development. Ang-2-VEGF-A CrossMab treatment led to a strong inhibition of angiogenesis and an enhanced vessel maturation phenotype. Neoadjuvant combination with chemotherapy resulted in complete tumor regression in primary tumor-bearing Ang-2-VEGF-A CrossMab-treated mice. In contrast to Ang-1 inhibition, anti-Ang-2-VEGF-A treatment did not aggravate the adverse effect of anti-VEGF treatment on physiologic vessels. Moreover, treatment with Ang-2-VEGF-A CrossMab resulted in inhibition of hematogenous spread of tumor cells to other organs and reduced micrometastatic growth in the adjuvant setting. These data establish Ang-2-VEGF-A CrossMab as a promising antitumor, antiangiogenic, and antimetastatic agent for the treatment of cancer.