Development of novel VEGF decoy receptor fusion protein, VEGF-Grab, targeting tumor angiogenesis

Abstract

Anti-angiogenic therapy targeting vascular endothelial growth factor A (VEGF-A) have been commonly used in clinic for advanced cancers for the past decade. But its clinical effi-cacy is limited with some drawbacks such as acquisition of resistance, and activation of compensatory pathways resulting from the elevated circulating VEGF-B and placenta growth factor (PlGF). To bypass some of these disadvantages, we developed a novel glyco-sylated soluble decoy receptor, named VEGF-Grab, which can neutralize VEGF-A, VEGF-B, and PlGF. VEGF-Grab contains the second and third immunoglobulin (Ig)-like domains of VEGF receptor 1 (VEGFR1) fused to IgG1 Fc, and three potential glycosylation sites were introduced in third Ig-like domain of VEGF-Grab by mutagenesis. Compared to VEGF-Trap, VEGF-Grab showed more potent decoying activity against VEGF and PlGF, which is mainly attributed to its VEGFR1 backbone. Most importantly, the negatively charged O-glycans attached to the third Ig-like domain of VEGFR1 counterbalanced the originally positively charged VEGFR1 backbone, consequently minimizing the non-specific binding of VEGF-Grab to extracellular matrix, and resulting in the much improved pharma-cokinetic profiles. These advancements led to stronger and more durable anti-angiogenic, anti-tumor, and anti-metastatic efficacy in both implanted and spontaneous tumor models compared to VEGF-Trap, while its toxicity profiles were comparable to VEGF-Trap. Col-lectively, our results highlight VEGF-Grab as a promising therapeutic candidate for further clinical drug development.