SUMMARY Id helix-loop-helix (HLH) proteins (Id1–4) bind E protein bHLH transcription factors, preventing them from forming active transcription complexes that drive changes in cell states. Id proteins are primarily expressed during development to inhibit differentiation, but they become re-expressed in adult tissues in diseases of the vasculature and cancer. We show that the genetic loss of Id1/Id3 reduces ocular neovascularization in mouse models of wet age-related macular degeneration (AMD) and retinopathy of prematurity (ROP). An in silico screen identifies AGX51, a small-molecule Id antagonist. AGX51 inhibits the Id1-E47 interaction, leading to ubiquitin-mediated degradation of Ids, cell growth arrest, and reduced viability. AGX51 is well-tolerated in mice and phenocopies the genetic loss of Id expression in AMD and ROP models by inhibiting retinal neovascularization. Thus, AGX51 is a first-in-class compound that antagonizes an interaction formerly considered undruggable and that may have utility in the management of multiple diseases.

Aberrant angiogenesis can cause or contribute to a number of diseases such as neovascular age-related macular degeneration (NVAMD). While current NVAMD treatments target angiogenesis, these treatments are not effective for all patients and also require frequent intravitreal injections. New agents and delivery systems to treat NVAMD could be beneficial to many patients. We have recently developed a serpin-derived peptide as an anti-angiogenic agent. Here, this peptide is investigated for activity in human retinal endothelial cells in vitro and for reducing angiogenesis in a laser-induced choroidal neovascularization mouse model of NVAMD in vivo. While frequent intravitreal injections can be tolerated clinically, reducing the number of injections can improve patient compliance, safety, and outcomes. To achieve this goal, and to maximize the in vivo activity of injected peptide, we have developed biodegradable polymers and controlled release particle formulations to extend anti-angiogenic therapy. To create these devices, the anionic peptides are first self-assembled into nanoparticles using a biodegradable cationic polymer and then as a second step, these nanoparticles are encapsulated into biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles. In situ, these particles show approximately zero-order, linear release of the anionic peptide over 200 days. These particles are made of safe, hydrolytically degradable polymers and have low endotoxin. Long-term in vivo experiments in the laser-induced neovascularization model for NVAMD show that these peptide-releasing particles decrease angiogenesis for at least fourteen weeks in vivo following a single particle dose and therefore are a promising treatment strategy for NVAMD.

We conducted a genome-wide association study (GWAS) on the outcome of anti-VEGF treatment for exudative age-related macular degeneration (AMD) in a prospective cohort. Four hundred and sixty-one treatment-naïve AMD patients were recruited at 13 clinical centers and all patients were treated with 3 monthly injections of ranibizumab followed by pro re nata regimen treatment for one year. Genomic DNA was collected from all patients for a 2-stage GWAS on achieving dry macula after the initial treatment, the requirement for an additional treatment, and visual acuity changes during the 12-month observation period. In addition, we evaluated 9 single-nucleotide polymorphisms (SNPs) in 8 previously reported AMD-related genes for their associations with treatment outcome. The discovery stage with 256 patients evaluated 8,480,849 SNPs, but no SNPs showed genome-wide level significance in association with treatment outcomes. Although SNPs with P-values of <5 × 10−6 were evaluated in replication samples of 205 patients, no SNP was significantly associated with treatment outcomes. Among AMD-susceptibility genes, rs10490924 in ARMS2/HTRA1 was significantly associated with additional treatment requirement in the discovery stage (P = 0.0023), and pooled analysis with the replication stage further confirmed this association (P = 0.0013). ARMS2/HTRA1 polymorphism might be able to predict the frequency of injection after initial ranibizumab treatment.