Anti‐angiogenic therapies using biological molecules that neutralize vascular endothelial growth factor‐A (VEGF‐A) have revolutionized treatment of retinal vascular diseases including age‐related macular degeneration (AMD). This study reports preclinical assessment of a strategy to enhance anti‐VEGF‐A monotherapy efficacy by targeting both VEGF‐A and angiopoietin‐2 (ANG‐2), a factor strongly upregulated in vitreous fluids of patients with retinal vascular disease and exerting some of its activities in concert with VEGF‐A. Simultaneous VEGF‐A and ANG‐2 inhibition was found to reduce vessel lesion number, permeability, retinal edema, and neuron loss more effectively than either agent alone in a spontaneous choroidal neovascularization (CNV) model. We describe the generation of a bispecific domain‐exchanged (crossed) monoclonal antibody (CrossMAb; RG7716) capable of binding, neutralizing, and depleting VEGF‐A and ANG‐2. RG7716 showed greater efficacy than anti‐VEGF‐A alone in a non‐human primate laser‐induced CNV model after intravitreal delivery. Modification of RG7716's FcRn and FcγR binding sites disabled the antibodies' Fc‐mediated effector functions. This resulted in increased systemic, but not ocular, clearance. These properties make RG7716 a potential next‐generation therapy for neovascular indications of the eye.

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To our knowledge, this is the first demonstration of visualized apoptosing RGC in vivo in a mouse. The improved image quality achieved with the HRAII compared with the Zeiss cSLO was validated by histology. This together with its enhanced maneuverability and the fact that it is already commercially available make the HRAII a potential tool for the early detection and diagnosis of glaucomatous disease in patients.

Vascular pathologies are known to be associated with age-related macular degeneration. Recently, age-related macular degeneration was associated with a single-nucleotide substitution of the complement factor H (CFH) gene, part of the alternative pathway of the complement system, a critical element in the innate immune response. Such polymorphisms are found in more than 50% of cases of age-related macular degeneration. Here we show that the absence of CFH causes an autoimmune response that targets the vascular endothelium of both the inner and outer retinal vascular networks. In CFH-knockout (cfh(-/-)) mice, C3 and C3b, key components of the complement system, are progressively deposited on retinal vessels, which subsequently become restricted and wither, resulting in a reduction of retinal blood supply. This result leads to increased oxygen stress. While such effects are not systemic, these structural changes are mirrored in functional changes with a substantial decline in retinal blood flow dynamics. When the system is challenged functionally by laser-induced choroidal neovascularization, fluorescein leakage was significantly smaller in cfh(-/-) mice compared with controls, likely due to reduced retinal perfusion. These data reveal that in both the presence and absence of exogenous challenge to the innate immune system, CFH is required to maintain normal levels of retinal perfusion. It is likely that C3 and C3b accumulation in the aged CFH-deficient retina is associated with complement-mediated retinal endothelium destruction.