Characterization of the Receptor-Ligand Competition of RO-104 IC50 Potencies

Abstract

Purpose : The objective of this study is to quantitate the IC50 potencies of the trispecific RO-104 to Vascular Endothelial Growth Factor-A (VEGF-A), Vascular Endothelial Growth Factor-C (VEGF-C), and Angiopoietin-2 (Ang-2) to their cognate receptors.

Methods : Inhibition of ligand receptor interaction was measured by enzyme-linked immunosorbent assay (ELISA). Briefly, coated ligands were tested by dose response dilutions of RO-104 as competitor to receptor binding. Detection of biotinylated receptors either VEGF R2/KDR or Tie2 were quantified by streptavidin-HRP secondary development. As a comparative reference we performed similar analysis with the VEGF-A and Ang-2 bispecific, faricimab.

Results : Target-receptor competition showed RO-104 showed slightly better IC50 (17.94 nM) for VEGF-A receptor binding than faricimab (26.11 nM). For Ang-2, RO-104 had a 12.42-fold reduction in IC50 (3.098 nM) compared to faricimab (38.46 nM). VEGF-C IC50 (3.775 nM) was specific to RO-104 whereas faricimab, as expected, showed no measurable inhibition at concentrations up to 100nM.

Conclusions : RO-104 demonstrated potent IC50s against all three targeted specificities. By similar comparative analysis to faricimab the potencies derived are therapeutically relevant, and even show greater potency with respect to Ang-2 and VEGF-C. Further testing is warranted to determine additional therapeutic benefits and potential to provide new and improved treatment for neovascular retinal disease.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Figure 1. IC₅₀ of RO-104 and faricimab in the single-target receptor interaction

 

Table 1. IC₅₀ of RO-104 and faricimab in the tri-specific target-receptor interaction