Abstract 3285: Ang-2-VEGF CrossMab, a novel bispecific human IgG1 antibody blocking VEGF-A and Ang-2 function mediates potent anti-tumoral and anti-angiogenic efficacy

Abstract

Abstract VEGF-A blockade has been validated clinically as a treatment for human cancers. Angiopoietin-2 (Ang-2) expression has been shown to function as a key regulator of blood vessel remodeling and tumor angiogenesis. In tumors Ang-2 is up-regulated and a bad prognostic factor. Recent data demonstrated that Ang-2 inhibitors, both as a single agent or in combination with chemo- or anti-VEGF therapy mediate anti-tumoral effects. We have recently described a novel generic method for the production of bivalent bispecific human IgG1 antibodies (CrossMabs) based on the crossover of the CH1 and CL domains within the Fab region of one half of a bispecific antibody combined with the knobs-into-holes technology to enforce heterodimerization of the Fc portion. Subsequently, we have applied the CrossMab technology for the generation of a bispecific antibody recognizing VEGF-A with one arm based on bevacizumab and recognizing Ang-2 with the other arm based on LC06, a highly Ang-2 selective human IgG1 antibody. The Ang-2-VEGF CrossMAb could be produced with good yields and purity by eukaryotic. Surface Plasmon resonance studies showed that the two different arms of the Ang-2-VEGF CrossMab retained their antigen binding affinity for VEGF-A and Ang-2 and interfered with VEGF-induced HUVEC proliferation and Ang-2 induced Tie2-phosphorylation in a similar manner than the parental antibodies. Crossmab showed very potent tumor growth inhibition in orthotopic (KPL-4) and in subcutaneous xenograft tumors (Colo205). In the orthotopic KPL-4 and the s.c. Colo205 xenograft we observed a strong inhibition of angiogenesis by ex vivo analysis. In the VEGF-induced cornea pocket assay Crossmab resulted in a complete shutdown of angiogenesis. We have generated a bispecific human IgG1 antibody blocking VEGF-A and Ang-2 function simultaneously. Our data indicate that the Ang-2-VEGF CrossMab mediates potent anti-tumoral, anti-metastatic and anti-angiogenic efficacy and represents a promising therapeutic agent for the therapy of cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3285. doi:10.1158/1538-7445.AM2011-3285