Gene therapy for glaucoma
What is Glaucoma?
Glaucoma is the leading cause of irreversible blindness worldwide and an estimated 11.2 million people will be bilaterally blind from the disease by 2020. Direct medical costs in the US alone are estimated at $3 billion per year, with 45% of the cost accounted for by prescription drug expenditure. The UK is comparable, where the prevalence of Glaucoma is estimated at 2% of all people over the age of 40 years.
The underlying causes are varied and no cure exists, but studies have shown that high pressure in the eye (intraocular pressure, or IOP) is a key feature and deceasing this pressure can largely prevent further visual loss by halting damage to the optic nerve. At present, there is no definitive treatment and what treatments there are risk sudden loss of vision, or arduous lifelong repeated administration.
Ciliary Body H&E section
Our approach
Using the now FDA approved adeno-associated virus (AAV) platform, we have delivered CRISPR-Cas9 to disrupt Aquaporin 1 (Aqp1) in the mouse ciliary body and shown the resulting reduced intraocular pressure (IOP) can prevent of ganglion cell loss in a mouse model of Glaucoma. To achieve this, we identified that the engineered AAV serotype ShH10 was capable of efficiently targeting the ciliary body non-pigmented epithelium in both mouse and human tissue.
Ongoing work
This work is continuing at the University of Bristol and we are now taking it forward in collaboration with industry to refine the approach for clinical trials. This is still a few years away and details will be highlighted when trials are close to starting.