Aflibercept and Faricimab Equipollently Restore Endothelial Barrier Function in VEGF-A165-Induced Permeability Model

Pathological vascular permeability is a hallmark of several ocular diseases, including diabetic macular edema (DME) and wet age-related macular degeneration (wAMD), leading to fluid leakage and vision loss. The primary driver of this leakage is vascular endothelial growth factor A (VEGF-A). Current anti-VEGF therapies, such as aflibercept, effectively inhibit VEGF-A. However, the angiopoietin-Tie2 pathway, particularly angiopoietin-2 (ANG2), also contributes to vascular instability. Faricimab, a newer bispecific antibody, targets both VEGF-A and ANG2, aiming for superior efficacy and durability. This study investigates if dual ANG2 blockade offers additional benefits for endothelial barrier integrity beyond VEGF-A inhibition alone.

This in vitro study utilized a human umbilical vein endothelial cell (HUVEC)-based model to assess drug effects on vascular permeability. Cells were initially exposed to VEGF-A165 to induce permeability. Subsequently, aflibercept (1.7 nM) or faricimab (2.0 nM) was added either simultaneously (preventive setting) or 24 hours later (therapeutic/rescue setting). Cell-layer permeability was quantitatively measured using the xCELLigence platform. Global transcriptomic changes were analyzed via RNA sequencing, and the release of angiogenesis-related proteins was quantified by electrochemiluminescence immunoassay.

Concurrent addition of aflibercept or faricimab significantly prevented the VEGF-A165-triggered increase in HUVEC cell-layer permeability (P = 0.0005). In the therapeutic/rescue setting, both drugs temporally improved cell-layer integrity (P = 0.0001). Notably, aflibercept was non-inferior to faricimab in both the preventive (P < 0.0001) and therapeutic/rescue (P < 0.0001) settings, indicating comparable efficacy in restoring barrier function. RNA sequencing revealed that both aflibercept and faricimab comparably downregulated VEGF-A165-induced angiogenesis-related genes. Specifically, they equipotently suppressed or reversed VEGF-A165 upregulation of ANGPT2 gene expression and angiopoietin-2 (ANG2) protein levels in the culture supernatant.

VEGF-A165-driven TEK gene expression and soluble Tie2 increase in culture supernatant were also reversed by both aflibercept and faricimab in both preventive and therapeutic settings. Despite significant upregulation of ANG2 expression after VEGF-A165 stimulation, the additional blockade of ANG2 with faricimab did not improve endothelial barrier integrity beyond VEGF-A165 blockade alone with aflibercept.