title: A novel engineered VEGF blocker with an excellent pharmacokinetic profile and robust anti-tumor activity.
abstract: BACKGROUND
  Relatively poor penetration and retention in tumor tissue has been documented for large molecule drugs including therapeutic antibodies and recombinant immunoglobulin constant region (Fc)-fusion proteins due to their large size, positive charge, and strong target binding affinity. Therefore, when designing a large molecular drug candidate, smaller size, neutral charge, and optimal affinity should be considered.
  
  
  METHODS
  We engineered a recombinant protein by molecular engineering the second domain of VEGFR1 and a few flanking residues fused with the Fc fragment of human IgG1, which we named HB-002.1. This recombinant protein was extensively characterized both in vitro and in vivo for its target-binding and target-blocking activities, pharmacokinetic profile, angiogenesis inhibition activity, and anti-tumor therapeutic efficacy.
  
  
  RESULTS
  HB-002.1 has a molecular weight of ~80 kDa, isoelectric point of ~6.7, and an optimal target binding affinity of <1 nM. The pharmacokinetic profile was excellent with a half-life of 5 days, maximal concentration of 20.27 μg/ml, and area under the curve of 81.46 μg·days/ml. When tested in a transgenic zebrafish embryonic angiogenesis model, dramatic inhibition in angiogenesis was exhibited by a markedly reduced number of subintestinal vessels. When tested for anti-tumor efficacy, HB-002.1 was confirmed in two xenograft tumor models (A549 and Colo-205) to have a robust tumor killing activity, showing a percentage of inhibition over 90% at the dose of 20 mg/kg. Most promisingly, HB-002.1 showed a superior therapeutic efficacy compared to bevacizumab in the A549 xenograft model (tumor inhibition: 84.7% for HB-002.1 versus 67.6% for bevacizumab, P<0.0001).
  
  
  CONCLUSIONS
  HB-002.1 is a strong angiogenesis inhibitor that has the potential to be a novel promising drug for angiogenesis-related diseases such as tumor neoplasms and age-related macular degeneration.
authors.affiliation: Department of Cell Biology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. lily.liu@huabobio.com.
authors.forename: Lily
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Cell Biology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. haijia.yu@huabobio.com.
authors.forename: Haijia
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Antibody Technology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. xin.huang@huabobio.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. hongzhi.tan@huabobio.com.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Antibody Technology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. song.li@huabobio.com.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Cell Biology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. yan.luo@huabobio.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. li.zhang@huabobio.com.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. sumei.jiang@huabobio.com.
authors.forename: Sumei
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. huifeng.jia@huabobio.com.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Jia
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. yao.xiong@huabobio.com.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Department of Project Management, Huabo Biopharm Co Ltd., Shanghai, 201203, China. ruliang.zhang@huabobio.com.
authors.forename: Ruliang
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Protein Science, Huabo Biopharm Co Ltd., Shanghai, 201203, China. ruliang.zhang@huabobio.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Huang
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-LIJ Health System, Manhasset, NY, 11030, USA. cchu@nshs.edu.|Department of Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, 11549, USA. cchu@nshs.edu.|Department of Molecular Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, 11549, USA. cchu@nshs.edu.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Chu
authors.affiliation: Department of Cell Biology, Huabo Biopharm Co Ltd., Shanghai, 201203, China. tian110602@huabobio.com.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Tian
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D015195:Drug Design; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D007074:Immunoglobulin G / Q000737:chemistry; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D011993:Recombinant Fusion Proteins / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000494:pharmacology; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D015027:Zebrafish / Q000196:embryology
chemical_list: D020533:Angiogenesis Inhibitors; C000605334:HB-002.1 fusion protein; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1