Vascular Endothelial Growth Factor Antagonists: Promising Players in the Treatment of Neovascular Age-Related Macular Degeneration

Abstract

Neovascular age-related macular degeneration (nAMD) treatment has been revolutionized by the introduction of vascular endothelial growth factor antagonists (anti-VEGF), but the need for frequent intravitreal injections poses a heavy burden to patients and physicians. Evolving anti-VEGF therapies include longer duration agents, approaches that target multiple pathways, topical anti-VEGF agents, sustained-release, and genetic therapies. Abicipar pegol, a designed ankyrin repeat protein (DARPin), demonstrated the ability to maintain stable visual acuity with 12-week dosing, but was not approved by the FDA due to higher than usual rates of intraocular inflammation. Conbercept, a recombinant anti-VEGF fusion protein, has been approved in China, and is in Phase 3 trials globally. KSI-301 is an anti-VEGF antibody biopolymer conjugate that allowed 66% of nAMD patients to maintain at least a 6-month treatment-free interval in Phase 1b studies. OPT-302, an inhibitor of VEGF-C/D, will be tested in phase 3 studies that compare anti-VEGF-A monotherapy against combination therapy with OPT-302. Faricimab is a bispecific anti-VEGF/Ang-2 antibody that upregulates the Tie-2 signaling pathway and promotes vascular stability; it is undergoing phase 3 trials with potential for 12- or 16-week dosing. PAN-90806 is a topical anti-VEGF agent that showed the ability to reduce injection frequency by 79% compared to ranibizumab monotherapy in a phase 1/2a trial. Sustained-release anti-VEGF therapies include the ranibizumab Port Delivery System (in phase 3 studies), GB-102 (Phase 2b), OTX-TKI (phase 1), and Durasert (preclinical). Suprachoroidal delivery of the tyrosine kinase inhibitor, axitinib, is in preclinical studies. Genetic therapies in phase 1 studies include RGX-314 and ADVM-022, which introduce a viral vector that modifies the retina's cellular apparatus to create an anti-VEGF biofactory, potentially serving as a one-time treatment. Further investigation is warranted for drugs and delivery systems that hope to advance visual outcomes and reduce treatment burden of nAMD.

Keywords: ADVM-022; CLS-AX; GB-102; KSI-301; OTX-TKI; PAN-90806; RGX-314; VEGF; abicipar pegol; age-related macular degeneration; conbercept; faricimab; ranibizumab port delivery system.