VEGFA (vascular endothelial growth factor A) is a potent angiogenic factor that regulates vascular development and pathological neovascularization. It is widely expressed in endothelial cells, smooth muscle cells, and stromal cells, and plays a critical role in tissue growth, repair, and tumor progression. Overexpression of VEGFA contributes to uncontrolled angiogenesis in cancers, diabetic retinopathy, and age-related macular degeneration (AMD), making VEGFA a central target in anti-angiogenic therapy.

In VEGFA humanized mice, the murine Vegfa gene exons 1–8 are replaced by the corresponding human VEGFA sequences, enabling the physiological expression of human VEGFA under native regulation. Importantly, these mice exhibit normal vascular morphology and angiogenesis, ensuring that human VEGFA expression does not disrupt baseline physiology.

VEGFA humanized mice express human VEGFA under endogenous regulation, supporting anti-VEGFA drug validation, angiogenesis studies, and preclinical ophthalmology and oncology research.

Key Advantages

• Fully humanized VEGFA locus ensures physiological expression of human VEGFA while preserving normal gene regulation.
• No baseline angiogenesis disruption, as confirmed by mCD31 staining—ideal for studying pathological angiogenesis without developmental artifacts.
• Retinal morphology preserved, supporting ophthalmic studies without structural confounds.
• Robust platform for anti-VEGFA therapeutics, validated by bevacizumab efficacy and angiogenesis inhibition.
• Versatile preclinical tool, suitable for efficacy testing of anti-VEGFA and bispecific therapeutics, including combination regimens.

Validation

• Lung homogenates from wild-type and homozygous B-hVEGFA (H/H) mice were tested using species-specific ELISA kits. Mouse VEGFA was detected only in WT mice, whereas human VEGFA was exclusively present in B-hVEGFA mice.
• Fundus photography of B-hVEGFA mice (male, n=3) shows no significant differences compared with WT mice, indicating preserved ocular structure.
• mCD31 immunohistochemistry in heart, liver, lung, kidney, and eye tissues of B-hVEGFA and C57BL/6 mice (female, 8 weeks old, n=3) revealed no significant differences in microvascular density, suggesting humanization has no impact on baseline angiogenesis.
• Bevacizumab inhibited tumor growth in B-hVEGFA mice bearing B-hVEGFA MC38 tumors (female, 6–7 weeks old, n=6). Additionally, CD31+ area in tumor tissues was significantly reduced, demonstrating suppressed angiogenesis and confirming model suitability for anti-VEGFA therapeutic evaluation.

Application

Preclinical oncology research

• Evaluation of anti-VEGFA therapies (e.g., bevacizumab) in solid tumor models.
• Studies on tumor angiogenesis, vascular normalization, and resistance mechanisms.

Ophthalmology models

• Preclinical testing of anti-VEGFA drugs for age-related macular degeneration (AMD).
• Evaluation of therapeutic strategies for diabetic retinopathy and retinal neovascularization.

Vascular biology and angiogenesis studies

• Mechanistic studies of human VEGFA signaling in endothelial cells and stromal cells.
• Analysis of angiogenesis in physiological and pathological contexts.

Antibody and biologics validation

• In vivo efficacy testing of anti-VEGFA antibodies and biosimilars.
• Preclinical evaluation of VEGFA-targeted fusion proteins and bispecific antibodies.

Combination therapy studies

• Assessment of anti-VEGFA agents combined with chemotherapy, radiotherapy, or immunotherapy.
• Investigation of synergistic effects in tumor regression and vascular modulation.

Biomarker discovery

• Identification of VEGFA-related biomarkers for response prediction and resistance profiling.
• Development of translational endpoints for clinical trial design.

Gene targeting strategy for B-hVEGFA mice. The exons 1-8 of mouse Vegfa gene that encode the full-length protein were replaced by human VEGFA exons 1-8 in B-hVEGFA mice.

Strain-specific VEGFA expression was analyzed in homozygous VEGFA humanized mice by ELISA. Lung homogenates were collected from wild-type (+/+) and homozygous VEGFA (H/H) humanized mice, and analyzed with species-specific VEGFA kits. Mouse VEGFA was detected only in wild-type mice, while human VEGFA was exclusively detected in B-hVEGFA mice. ELISA confirmed species-specific VEGFA expression, validating successful humanization of the VEGFA gene.

Fundus photographs of B-hVEGFA mice showed no significant differences compared with wild-type mice (male, n=3), indicating preserved retinal morphology. Fundus imaging confirmed that human VEGFA expression does not alter baseline ocular structure.

Mouse CD31 expression was assessed by immunohistochemistry in the heart, liver, lung, kidney, and eye of C57BL/6 and VEGFA humanized mice (female, 8 weeks old, n=3). No significant differences in the proportion of mCD31+ cells were observed between the two groups across all tissues examined. These results suggest that VEGFA humanization has no effect on baseline angiogenesis.

Antitumor activity of anti-human VEGFA antibody in VEGFA humanized mice.
(A) Anti-human VEGFA antibody (bevacizumab) significantly inhibited tumor growth in VEGFA humanized mice bearing B-hVEGFA MC38 tumors. Tumor cells were subcutaneously implanted into homozygous VEGFA humanized mice (female, 6–7 weeks old, n=6). Mice were grouped when tumor volumes reached ~100 mm³ and treated with bevacizumab according to indicated schedules.
(B) Body weight changes were monitored during treatment.
(C) CD31 immunostaining showed a reduction in vascular endothelial cell area in tumor tissues following bevacizumab treatment, confirming anti-angiogenic efficacy.
These results demonstrate that VEGFA humanized mice provide a robust preclinical model for in vivo evaluation of anti-human VEGFA antibodies. Values are expressed as mean ± SEM.

Faricimab reduces CNV lesion leakage and size in VEGFA humanized mice. VEGFA humanized mice were used to establish a choroidal neovascularization (CNV) model by laser treatment and randomly divided into four groups (n=4/group, female, 6–7 weeks old). PBS (control) or the bispecific antibody faricimab (targeting VEGFA and ANG2) was administered intravitreally at different doses.(A) Fundus fluorescein angiography (FFA) was performed on Day 7 to quantify leakage scores (Grade I–IV) and lesion area.(B) Faricimab treatment significantly reduced leakage scores and lesion size compared to PBS, in a dose-dependent manner (*P<0.05, **P<0.01, One-Way ANOVA).
These results confirm that VEGFA humanized mice are suitable for ophthalmology drug development, particularly anti-VEGFA and anti-ANG2 combination therapies. Data were co-validated with Pharmalegacy.

Q1: What are VEGFA humanized mice used for?

A1: They are designed for preclinical efficacy testing of anti-VEGFA therapies, including cancer, diabetic retinopathy, and age-related macular degeneration models.

Q2: How is human VEGFA expression validated in VEGFA humanized mice?

A2: ELISA assays confirmed species-specific VEGFA expression, with human VEGFA detected exclusively in homozygous VEGFA humanized mice and absent in WT controls.

Q3: Do VEGFA humanized mice show normal vascular development?

A3: Yes. mCD31 immunohistochemistry revealed no significant differences in vascular density compared to WT mice, confirming preserved baseline angiogenesis.

Q4: Can VEGFA humanized mice be used for ophthalmology studies?

A4: Yes. Fundus imaging confirmed normal retinal morphology, making them suitable for testing anti-VEGFA treatments in eye diseases such as AMD.

Q5: Which anti-VEGFA antibody has been validated in this model?

A5: Bevacizumab treatment significantly inhibited tumor growth and reduced angiogenesis in VEGFA humanized mice, confirming translational relevance for therapeutic evaluation.