A novel vascular endothelial growth factor-trap KP-VR2 with enhanced ligand blocking

Antiangiogenic therapies targeting vascular endothelial growth factor (VEGF)-A have been commonly used in clinics to treat cancers over the past decade. However, their clinical efficacy has been limited, with drawbacks including the acquisition of resistance and activation of compensatory pathways resulting from elevated circulating VEGF-B and placental growth factor (PlGF) levels. Thus, we developed a novel VEGF-Trap, KP-VR2, which can neutralize VEGF-A, VEGF-B, and PlGF to mediate these problems. KP-VR2 consists of two consecutive second Ig-like domains (D2s) of VEGF receptor 1 (VEGFR-1) fused to human IgG1 Fc. KP-VR2 showed more potent decoy activity than the current VEGF-Trap against VEGF and PlGF. Most importantly, two consecutive D2s of VEGFR-1 can generate two putative binding sites, resulting in a significant improvement in binding capacity. These advances resulted in stronger antitumor efficacy in implanted tumor models than aflibercept and bevacizumab. Overall, the results of this study highlight KP-VR2 as a promising therapeutic candidate for further clinical drug development.