Abstract

Antiangiogenic therapies targeting VEGFA have been commonly used in clinics to treat cancers over the past decade. However, their clinical efficacy has been limited, with drawbacks including acquisition of resistance and activation of compensatory pathways resulting from elevated circulating VEGFB and placental growth factor (PlGF). To bypass these disadvantages, we developed a novel glycosylated soluble decoy receptor fusion protein, VEGF-Grab, that can neutralize VEGFA, VEGFB, and PlGF. VEGF-Grab has the second and third immunoglobulin (Ig)-like domains of VEGF receptor 1 (VEGFR1) fused to IgG1 Fc, with three potential glycosylation sites introduced into the third Ig-like domain of VEGF-Grab by mutagenesis. Compared with VEGF-Trap, VEGF-Grab showed more potent decoy activity against VEGF and PlGF, mainly attributed to the 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, minimizing nonspecific binding of VEGF-Grab to the extracellular matrix, and resulting in greatly improved pharmacokinetic profile. These advancements led to stronger and more durable antiangiogenic, antitumor, and antimetastatic efficacy in both implanted and spontaneous tumor models as compared with VEGF-Trap, while toxicity profiles were comparable with VEGF-Trap. Collectively, our results highlight VEGF-Grab as a promising therapeutic candidate for further clinical drug development.

Highlights

  • VEGFA is a critical regulator of tumor angiogenesis, mainly through the activation of its primary receptor, VEGF receptor 2 (VEGFR2; refs. 1–3)

  • VEGFA is expressed in most tumor cells and corresponding stromal cells throughout tumor progression, whereas VEGFR2 is highly expressed in growing tumor vessels, leading to the formation of structurally and functionally malformed tumor blood vessels [1, 4]

  • Residues in VEGF receptor 1 (VEGFR1) D3 participate in the high-affinity binding of VEGFA and placental growth factor (PlGF) [18]

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Summary

Introduction

VEGFA is a critical regulator of tumor angiogenesis, mainly through the activation of its primary receptor, VEGF receptor 2 (VEGFR2; refs. 1–3). VEGFA is a critical regulator of tumor angiogenesis, mainly through the activation of its primary receptor, VEGF receptor 2 VEGFA is expressed in most tumor cells and corresponding stromal cells throughout tumor progression, whereas VEGFR2 is highly expressed in growing tumor vessels, leading to the formation of structurally and functionally malformed tumor blood vessels [1, 4]. VEGFA binds to the second immunoglobulin (Ig) homology domain (D2) of the extracellular region of VEGFR2, resulting in activation of proangiogenic signaling [5]. Much effort has been devoted to targeting this VEGFA/VEGFR2 signaling pathway using monoclo-. Note: Supplementary data for this article are available at Molecular Cancer Therapeutics Online (http://mct.aacrjournals.org/).

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