Simultaneous blockade of VEGF and Dll4 by HD105, a bispecific antibody, inhibits tumor progression and angiogenesis

Abstract

Several angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway have been approved for cancer treatment. However, VEGF inhibitors alone were shown to promote tumor invasion and metastasis by increasing intratumoral hypoxia in some preclinical and clinical studies. Emerging reports suggest that Delta-like ligand 4 (Dll4) is a promising target of angiogenesis inhibition to augment the effects of VEGF inhibitors. To evaluate the effects of simultaneous blockade against VEGF and Dll4, we developed a bispecific antibody, HD105, targeting VEGF and Dll4. The HD105 bispecific antibody, which is composed of an anti-VEGF antibody (bevacizumab-similar) backbone C-terminally linked with a Dll4-targeting single-chain variable fragment, showed potent binding affinities against VEGF (K D : 1.3 nM) and Dll4 (K D : 30 nM). In addition, the HD105 bispecific antibody competitively inhibited the binding of ligands to their receptors, i.e., VEGF to VEGFR2 (EC 50 : 2.84 § 0.41 nM) and Dll4 to Notch1 (EC 50 : 1.14 § 0.06 nM). Using in vitro cell-based assays, we found that HD105 effectively blocked both the VEGF/ VEGFR2 and Dll4/Notch1 signaling pathways in endothelial cells, resulting in a conspicuous inhibition of endothelial cell proliferation and sprouting. HD105 also suppressed Dll4-induced Notch1-dependent activation of the luciferase gene. In vivo xenograft studies demonstrated that HD105 more efficiently inhibited the tumor progression of human A549 lung and SCH gastric cancers than an anti-VEGF antibody or anti-Dll4 antibody alone. In conclusion, HD105 may be a novel therapeutic bispecific antibody for cancer treatment.

ABT-165, a Dual Variable Domain Immunoglobulin (DVD-Ig) Targeting DLL4 and VEGF, Demonstrates Superior Efficacy and Favorable Safety Profiles in Preclinical Models

“…We found that ABT-165 was well tolerated in monkeys even at doses as high as 200 mg/kg, with nonadverse histopathologic findings noted only in the liver and thymus. Of note, DLL4 inhibition alone is known to induce endothelial cell proliferation that could be VEGF-dependent (6,39). Therefore, we hypothesized that dual DLL4 and VEGF inhibition may mitigate some normal tissue toxicity derived from DLL4 inhibition alone by potentially restoring the balance of DLL4 and VEGF pathways thereby, preventing proliferation of endothelial cells.…”

“…A bispecific approach represents an attractive combination strategy to efficiently inhibit both targets, and currently two other DLL4/VEGF bispecific biologics in addition to ABT-165 have been recently reported, HD105 (39) and OMP-305B83 (40). HD105 was engineered by fusing a DLL4-targeting single-chain variable fragment (scFv) to the C-terminal of an anti-VEGF mAb.…”

A promising cancer diagnosis and treatment strategy: targeted cancer therapy and imaging based on antibody fragment

“…In addition to single-target antibody fragment, there is also multiple-target antibody fragment for the treatment of tumours. Recently, bispecific antibodies HD105 that inhibit angiogenesis by targeting vascular endothelial growth factor (VEGF) and Delta-like ligand 4 (DII4) are constructed [78]. Both target sites promote tumour angiogenesis in a variety of tumours, and DII4 is also associated with cancer stem cells.…”

Development, validation, and application of ELISA for detection of anti-HD105 antibodies in pre-clinical safety evaluation using monkeys

“…The tumor-suppressive effects are more prominent when both VEGF and DLL4 agents are used in combination [15][16][17]. HD105, a novel antibody designed to target both VEGF and DLL4, is formed by an anti-VEGF antibody linked with anti-DLL4 single-chain Fv [18].…”