Abstract
Purpose :
Persistence of intraretinal fluid has been observed in most patients with diabetic macular edema (DME) after anti-angiogenic therapies, including aflibercept and faricimab. One of the reasons is due to unchecked inflammation, specifically interleukin 6 (IL-6). We aimed to develop a humanized tri-specific antibody (EB-105) to inhibit vascular endothelial growth factor (VEGF), IL-6 receptor (IL-6R) and angiopoietin 2 (Ang-2) for DME.
Methods :
A series of molecules were engineered, expressed, purified, and characterized for their binding affinities to VEGF-A, VEGF-B, placental growth factor (PlGF); IL-6R; Ang-1 and Ang-2. Promising molecules were evaluated for their effects on inhibition of VEGF-A/VEGF receptor 2 (VEGF-R2), IL-6/IL-6R and Ang-2/Tie-2 signaling using engineered cells corresponding to each pathway. A lead molecule coded as EB-105 was tested via intravitreal (IVT) injection in two animal models, including DL-aminoadipic acid (DL-AAA)-induced pre-retinal neovascularization (PRN) in pigmented rabbits and laser-induced choroidal neovascularization (CNV) in monkeys. EB-105 has proceeded to chemistry manufacturing and controls (CMC) development, followed by pre-clinical studies for investigational new drug (IND) filing.
Results :
EB-105 potently binds to VEGF-A, VEGF-B, PlGF; IL-6R and Ang-2 but not Ang-1, with a binding affinity comparable to aflibercept, tocilizumab and faricimab in each respective pathway. Sequential binding studies using surface plasmon resonance indicate that EB-105 is capable of binding to VEGF-A, IL-6R and Ang-2 simultaneously and independently. Relevant cell-based functional studies confirmed that EB-105 potently inhibits VEGF-A mediated VEGF-R2 signaling and blocks IL-6 and Ang-2 binding to their corresponding receptors, with an inhibitory efficacy comparable to aflibercept, tocilizumab and faricimab in relevant pathways. EB-105 effectively inhibits vascular leakage in DL-AAA-induced PRN and laser-induced CNV. EB-105 has been formulated to 80 mg/ml through CMC development. A single dose of IVT injection of EB-105 as high as 8 mg/100μl/eye did not induce obvious inflammation in posterior vitreous, retina and optic nerve head in monkeys.
Conclusions :
We have developed EB-105 as a novel tri-specific antibody that effectively inhibits VEGF, IL-6R and Ang-2 signaling in pre-clinical studies. A Phase 1b first-in-human safety and tolerability study in DME is planned for 2024.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.