Non-neutralizing antibodies increase endogenous circulating Ang1 levels

Abstract

Ang1 is a soluble ligand to receptor Tie2, and increasing the circulating Ang1 level may improve vascular stabilization under certain disease conditions. Here, we found that the circulating Ang1 level was significantly increased in cynomolgus monkeys treated with non-neutralizing anti-Ang1 antibodies. Improving the antibodies’ pharmacokinetic properties by IgG Fc mutations further increased the circulating Ang1 level. However, the mutations decreased the thermal stability of the molecules, which may limit their use as therapeutic antibodies. Nevertheless, we showed that non-neutralizing antibodies may have therapeutic potential by increasing the level of a target molecule in the circulation.

Effect of Novel Biotherapeutic Elevating Angiopoietin 1 on Progression of Diabetic Nephropathy in Diabetic/Obese Mice

“…Finally, the present study tested a recently described and novel biotherapeutic modality to increase endogenous ANGPT1 protein levels using a non-neutralizing anti-ANGPT1 antibody, referred to as O010, that binds within the coiled-coil domain of ANGPT1 (a site independent of the receptor binding domain) and reduces the clearance, resulting in increased circulating concentrations of ANGPT1. It was previously shown that the O010 antibody does not interfere with ANGPT1 binding to TIE2, nor does it reduce pAKT signaling in a cell line (Zheng et al, 2018). Furthermore, this antibody significantly increases circulating ANGPT1 levels in healthy cynomolgus monkeys (Zheng et al, 2018) consistent with the targeted mechanism-of-action.…”

“…It was previously shown that the O010 antibody does not interfere with ANGPT1 binding to TIE2, nor does it reduce pAKT signaling in a cell line (Zheng et al, 2018). Furthermore, this antibody significantly increases circulating ANGPT1 levels in healthy cynomolgus monkeys (Zheng et al, 2018) consistent with the targeted mechanism-of-action. The present study also demonstrated an increase in circulating ANGPT1 with O010 in db/db UNx mice, however the molecule failed to reduce renal injury endpoints including no effect on albuminuria or histopathology scores, including the incidence of glomerulosclerosis and interstitial lesions.…”

“…We also demonstrated proof of concept that the same molecule, termed O010, significantly elevates circulating levels of the protein in cynomolgus monkeys after a single injection of the antibody (Zheng et al, 2018).…”

“…Materials (antibody, DNA Minicircle, AAV): Mouse ANGPT1 minicircle was obtained from System Biosciences (Palo Alto, CA). The ANGPT1 antibody O010, and the IgG control antibody were produced at Boehringer Ingelheim Pharmaceuticals as previously disclosed (Zheng et al, 2018). The COMP-Ang1 AAV (Cho et al, 2004) was produced as follows: a synthetic piece of DNA containing a Kozak sequence followed by a secretory signal sequence for hemagglutinin, the coiled-coil domain of rat cartilage oligomeric matrix protein fused to the fibrinogen-like domain of human Ang1 (Cho et al, 2004) and a WPRE sequence was synthesized at GeneArt (Regensburg, Germany) and cloned into the pAAV-MCS (Agilent Technologies, catalog no.…”

“…It was previously reported circulating ANGPT1 levels were significantly increased in cynomolgus monkeys treated with a non-neutralizing anti-ANGPT1 antibody (Zheng et al, 2018). In order to demonstrate the potential benefit of increasing circulating ANGPT1 levels on the renoprotective efficacy in db/db UNx mice, a study was performed utilizing the same biotherapeutic molecule, termed O010.…”