Abstract
Purpose :
Glaucoma is one of the leading causes of irreversible blindness, posing a significant challenge to healthcare providers. Elevated intraocular pressure (IOP) is considered a major risk for the pathogenesis of glaucoma. While conventional therapies have shown effectiveness in lowering IOP, patient compliance for these treatments is poor. Gene therapy has emerged as a promising approach to address compliance issues, offering new hope for patients. This work aimed to develop an AAV-based gene therapy product to reduce IOP by inhibiting Rho kinase (ROCK) activity in human trabecular meshwork (HTM), which provides the resistance to aqueous humor outflow that is needed to maintain a physiological IOP.
Methods :
An scAAV vector (GVB-2001) was designed to express a transgene to inhibit the activity of ROCK in trabecular meshwork. Research grade GVB-2001 was manufactured for proof-of-concept studies. For the in vitro part, ROCK activity measured by ELISA was used to evaluate the efficiency of viral transduction in HTM cells. Different time points after infection, and several MOI (Multiplicity of Infection) were tested. For in vivo study, an ocular hypertensive rat model was created by infecting rat eyes with AdhBMP2. It was used to test if intracameral injection of GVB-2001 could reduce IOP. Rats were sacrificed 2 weeks after AAV injection and qPCR was performed to study the biodistribution of GVB-2001 in ocular tissues.
Results :
The transgene was highly expressed in HTM cells after viral infection (Fig.1A). The GVB-2001 infection also significantly reduced ROCK activity in HTM cells at different time points and different MOI (Fig.1B&C). In the rat model, IOP reading increased after injection of AdhBMP2 (Fig.2A). Then, a significant IOP reduction was observed 7 days post-AAV injection and maintained through day 14 (Fig.2B). Biodistribution confirmed that GVB-2001 could only be detected in TM of rat eyes, not in iris, retina, nor in cornea (Fig.2C). Dose-escalating efficacy and tox studies are ongoing.
Conclusions :
GVB-2001 is a strong candidate for glaucoma gene therapy to reduce IOP by inhibiting ROCK activity in trabecular meshwork. The proof-of-concept animal study supports the potential of a gene therapy approach to achieve a stable, durable IOP reduction with a single intracameral injection.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.