A human neutralizing antibody specific to Ang-2 inhibits ocular angiogenesis

Angiogenesis, a critical contributor to ocular as well as neoplastic diseases, is stimulated by endothelial production of angiopoietin-2 (Ang2). Our objective was to determine the requirement of ocular angiogenesis for Ang2 in animal models of disease.

We developed and compared the effect of a novel human Ang2 antibody with a pan-angiopoietin strategy on angiogenesis in ocular angiogenesis in animal models of oxygen-induced retinopathy, and laser photocoagulation and confirmed its efficacy in xenografted human colorectal tumors.

Human anti-Ang2 and anti-angiopoietin1(Ang1)/Ang2 antibodies blocked colorectal carcinoma growth in immuno-compromised mice (p < 0.001, n = 6). Injection of 1 μg of Ang2 or Ang2/Ang1 antibody-inhibited angiogenesis in models of retinal (p < 0.001, n = 6), and choroidal neovascularization (p < 0.001, n = 11-13 per group) to levels similar to that with anti-VEGF antibodies. There was no difference between Ang2 specific and Ang1/Ang2 bi-specific antibodies. In vitro, Ang2 antibodies showed no cytotoxicity and did not inhibit endothelial cell migration or proliferation.

Thus, human Ang2 antibodies are potentially therapeutic agents for ocular neovascularization in models of retinal and choroidal neovascularization, in the absence of VEGF inhibition.