Vascular diseases, encompassing a spectrum from oncological indications to sight-threatening diabetic retinopathy, present formidable global health challenges. Central to maintaining vascular homeostasis, Angiopoietin-2 (ANG2) has emerged as a pivotal therapeutic target, its dysregulated expression being intimately linked to the pathogenesis of these debilitating conditions. The recent clinical success of bispecific antibodies simultaneously targeting both ANG2 and Vascular Endothelial Growth Factor A (VEGFA), exemplified by Roche's Faricimab, underscores a critical and unmet need for highly predictive animal models to accelerate the trajectory of drug discovery and development.
Angiopoietin-2 (ANG2), a secreted glycoprotein encoded by the ANGPT2 gene, orchestrates vascular stability and pathological remodeling through its specific binding to the TIE2 receptor. Functionally, ANG2 operates as a dimer, exhibiting a nuanced, concentration-dependent modulation of vascular processes. In the presence of VEGFA, low concentrations of ANG2 can promote angiogenesis. Conversely, at higher concentrations, ANG2 acts as an antagonist, disrupting TIE2 receptor signaling to compromise vascular stability, leading to characteristic hallmarks such as vascular leakage and inflammatory responses.
This intricate regulatory mechanism is underpinned by three distinct structural domains: a C-terminal fibrinogen-like domain directly mediating TIE2 receptor interaction, a central coiled-coil domain essential for protein dimerization, and an N-terminal superfamily domain governing protein secretion and subcellular localization. Dysregulation of ANGPT2 gene expression is broadly associated with diverse pathological processes, including aberrant tumor angiogenesis, microvascular compromise in diabetic retinopathy, and maladaptive vascular remodeling in chronic inflammatory states.
Figure 1. Regulatory Mechanism of Ang/Tie Signaling Pathway[1]
VEGFA (Vascular Endothelial Growth Factor A) and ANGPT2 represent synergistic molecular orchestrators of angiogenesis. VEGFA directly drives endothelial cell proliferation and migration via its cognate receptor VEGFR2 (KDR/Flk-1). Concurrently, ANGPT2 modulates vascular maturation and stability by fine-tuning the TIE2 signaling pathway. Together, they establish a pivotal "angiogenic switch" mechanism: VEGFA induces the initial sprouting of new vessels, while ANGPT2 subsequently determines the ultimate fate of these nascent structures—either stabilization (when TIE2 is activated) or regression (when ANGPT2 inhibits TIE2). Their reciprocal interactions are exquisitely sensitive to microenvironmental cues, such as hypoxia (which upregulates VEGFA via HIF-1α) and inflammation (which induces ANG2 release via TNF-α).
VEGFA (Vascular Endothelial Growth Factor A) and ANGPT2 represent synergistic molecular orchestrators of angiogenesis. VEGFA directly drives endothelial cell proliferation and migration via its cognate receptor VEGFR2 (KDR/Flk-1). Concurrently, ANGPT2 modulates vascular maturation and stability by fine-tuning the TIE2 signaling pathway. Together, they establish a pivotal "angiogenic switch" mechanism: VEGFA induces the initial sprouting of new vessels, while ANGPT2 subsequently determines the ultimate fate of these nascent structures—either stabilization (when TIE2 is activated) or regression (when ANGPT2 inhibits TIE2). Their reciprocal interactions are exquisitely sensitive to microenvironmental cues, such as hypoxia (which upregulates VEGFA via HIF-1α) and inflammation (which induces ANG2 release via TNF-α).
The inherent complexity of the ANG2 pathway, characterized by its pleiotropic and context-dependent roles in both angiogenesis and inflammation, underscores the intrinsic limitations of monotherapy. This biological nuance has propelled the research community towards combination treatment strategies. For example, bispecific antibodies designed to simultaneously target both VEGFA and ANG2, or the strategic combination of ANG2 inhibitors with immune checkpoint blockers, exemplify multi-pathway synergistic interventions. These innovative approaches aim to more effectively modulate vascular abnormalities and reshape the immune microenvironment, thereby circumventing monotherapy resistance and substantially enhancing clinical outcomes.
As of 2025, therapies targeting both ANG2 and VEGFA continue to hold significant clinical importance in neovascular eye diseases, such as neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME), as well as in specific solid tumor indications.
- Ophthalmology: Roche's Vabysmo (Faricimab), capitalizing on its dual-target inhibition advantage, led the market in 2024 with global sales reaching 3.864 billion Swiss Francs (approximately $4.60 billion USD) [3]. Its sustained efficacy is continuously corroborated by accumulating real-world data [5]. Concurrently, Chinese pharmaceutical companies, including China Medical System Holdings Limited, are rapidly advancing similar tetravalent bispecific antibodies. These novel nanobody designs boast attributes such as high affinity and reduced dosing frequency. As of March 2024, clinical trials for nAMD have progressed, with the first patient dosed in Phase II after successful completion of Phase I [4].
- Oncology: Dual-target inhibition, by actively remodeling the tumor microenvironment to foster CD8+ T cell infiltration, has become a focal point for combination immunotherapy research (e.g., combining VEGF and ANG2 inhibitors with PD-1 antibodies) [2]. This strategy is particularly promising in challenging and refractory tumors like glioblastoma, where synergistic mechanisms are being intensively explored to overcome therapeutic resistance.
Presently, while ANG2 and VEGFA-targeting therapies are firmly established in ophthalmic practice, their application in oncology remains an area of ongoing mechanistic elucidation and clinical breakthrough.
To address the critical need for advanced preclinical models, researchers have developed innovative humanized ANGPT2 and VEGFA/ANGPT2 double-humanized mouse models. These sophisticated platforms leverage precise gene replacement technology to enable the controlled expression of human proteins, offering invaluable tools for evaluating single-target therapeutics. Crucially, they also serve as highly relevant experimental systems for assessing the efficacy of contemporary bispecific antibodies and combination therapies, thereby addressing existing bottlenecks in anti-angiogenic treatment strategies.
These meticulously engineered models offer unparalleled utility to:
- Accelerate Translational Validation: Expedite the assessment of ANGPT2's translational significance as a therapeutic target for both vascular and inflammatory diseases.
- Facilitate Enhanced Drug Development: Drive the discovery and development of more potent and effective VEGFA/ANGPT2 dual-target therapeutic agents.
- Optimize Clinical Efficacy Assessment: Improve the efficiency and predictive power of preclinical efficacy evaluations for existing and novel anti-angiogenic drugs, thereby providing robust preclinical support for innovative drug development.
| Product name | Catalog | Strain name | Type |
|---|---|---|---|
| B6-hANG2(ANGPT2) | C001615 | C57BL/6JCya-Angpt2tm1(hANGPT2)/Cya | ANGPT2 Gene Humanization |
| B6-hVEGFA/hANGPT2 | C001691 | C57BL/6JCya-Vegfatm1(hVEGFA)Angpt2tm1(hANGPT2)/Cya | VEGFA/ANGPT2 Gene Humanization |
mRNA Expression Level Detection: RT-qPCR analysis unequivocally demonstrates significant expression of the human ANGPT2 gene and a complete absence of endogenous mouse Angpt2 gene expression in homozygous B6-hANG2(ANGPT2) mice, confirming successful humanization.
Western Blot analysis revealed the presence of target bands in both wild-type (WT) and B6-hANG2(ANGPT2) mouse plasma. While this could be partly attributable to high human-mouse sequence homology, B6-hANG2(ANGPT2) mice consistently exhibited discernibly higher ANG2 protein expression compared to WT mice.
ELISA results definitively confirmed the significant and specific expression of human ANG2 protein in both the serum and plasma of B6-hANG2(ANGPT2) mice, with consistent protein levels observed across both sample types. Critically, no human ANG2 protein was detected in WT mice, validating the human-specific expression.
Homozygous B6-hANG2(ANGPT2) mice exhibited normal ocular fundus morphology and retinal OCT (Optical Coherence Tomography) results, consistent with wild-type counterparts. Furthermore, scotopic (dark-adapted) and photopic (light-adapted) a- and b-wave amplitudes in 6-week-old homozygous B6-hANG2(ANGPT2) mice were virtually indistinguishable from wild-type controls, indicating preserved retinal function and integrity in the humanized models.
Beyond their established utility in oncology and ocular neovascular diseases such as neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME), these versatile humanized models hold significant promise for investigating a broader spectrum of vascular-related conditions, including:
- Atherosclerosis and Ischemic Diseases: Elucidating the precise roles of ANG2 and VEGFA in plaque formation, vessel occlusion, and the response to ischemic injury.
- Inflammatory Vascular Disorders: Exploring their critical involvement in the pathophysiology of conditions such as vasculitis and sepsis-induced vascular dysfunction.
- Wound Healing and Tissue Regeneration: Investigating their contributions to both physiological and impaired vascular repair processes and tissue regeneration.
- Diabetic Complications: Extending beyond retinopathy, assessing their impact on systemic diabetic complications like diabetic nephropathy and neuropathy.
These sophisticated humanized mouse models are designed to be invaluable assets for researchers aiming to accelerate the understanding and treatment of vascular diseases. By providing highly clinically relevant platforms, they facilitate robust preclinical studies and deepen insights into complex disease mechanisms. For those interested in exploring the full potential of these models, including access to comprehensive CRO services that range from preclinical study design to detailed phenotyping and pathological analysis, further information is available. These resources can significantly aid in lead optimization, candidate selection, and ultimately, the translation of scientific discoveries into impactful therapeutic solutions.
[1] Sha L, Zhao Y, Li S, Wei D, Tao Y, Wang Y. Insights to Ang/Tie signaling pathway: another rosy dawn for treating retinal and choroidal vascular diseases. J Transl Med. 2024 Oct 4;22(1):898. doi: 10.1186/s12967-024-05441-y. PMID: 39367441; PMCID: PMC11451039.
[2] Leong A, Kim M. The Angiopoietin-2 and TIE Pathway as a Therapeutic Target for Enhancing Antiangiogenic Therapy and Immunotherapy in Patients with Advanced Cancer. Int J Mol Sci. 2020 Nov 18;21(22):8689. doi: 10.3390/ijms21228689. PMID: 33217955; PMCID: PMC7698611.
[3] F. Hoffmann-La Roche Ltd. Communications appendix tables_FY 2024 Sales + Results [Internet]. Basel, Switzerland: F. Hoffmann-La Roche Ltd.; 2025. Vabysmo sales. Available from: https://roche.com/appendix-tables-fy-2024.pdf. Accessed June 7, 2025.
[4] China Medical System Holdings Limited. 2024 Annual Report. Hong Kong: China Medical System Holdings Limited; 2024. [Accessed June 7, 2025].
[5] Ferro Desideri L, Traverso CE, Nicolò M, Munk MR. Faricimab for the Treatment of Diabetic Macular Edema and Neovascular Age-Related Macular Degeneration. Pharmaceutics. 2023 May 5;15(5):1413. doi: 10.3390/pharmaceutics15051413. PMID: 37242655; PMCID: PMC10222467.
