Humanization of an anti-vascular endothelial growth factor monoclonal antibody for the therapy of solid tumors and other disorders.

TLDR

VEGF drives angiogenesis in tumors and diseases such as diabetic retinopathy and macular degeneration, and a murine anti‑VEGF antibody has shown potent anti‑angiogenic activity in preclinical models. We describe the humanization of the murine anti‑VEGF monoclonal antibody A.4.6.1. The antibody was humanized by site‑directed mutagenesis of the human framework, replacing both CDR and selected framework residues with murine sequences. The humanized antibody retains VEGF binding affinity and inhibits endothelial proliferation and tumor growth in vitro and in vivo with potency comparable to the original murine antibody, supporting its potential for treating solid tumors and other disorders.

Abstract

Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis associated with tumors and other pathological conditions, including proliferative diabetic retinopathy and age-related macular degeneration. The murine anti-human VEGF monoclonal antibody (muMAb VEGF) A.4.6.1 has been shown to potently suppress angiogenesis and growth in a variety of human tumor cells lines transplanted in nude mice and also to inhibit neovascularization in a primate model of ischemic retinal disease. In this report, we describe the humanization of muMAb VEGF A.4.6.1. by site-directed mutagenesis of a human framework. Not only the residues involved in the six complementarity-determining regions but also several framework residues were changed from human to murine. Humanized anti-VEGF F(ab) and IgG1 variants bind VEGF with affinity very similar to that of the original murine antibody. Furthermore, recombinant humanized MAb VEGF inhibits VEGF-induced proliferation of endothelial cells in vitro and tumor growth in vivo with potency and efficacy very similar to those of muMAb VEGF A.4.6.1. Therefore, recombinant humanized MAb VEGF is suitable to test the hypothesis that inhibition of VEGF-induced angiogenesis is a valid strategy for the treatment of solid tumors and other disorders in humans.