We believe our platform offers the potential for safer, targeted ocular gene therapy without some of the risks of surgery and subretinal administration. Suprachoroidal administration of gene therapy could ultimately enhance access to care because it does not require specialized gene therapy surgery treatment centers. The procedure for suprachoroidal injection is conducted in an office setting and is similar in terms of patient preparation and duration to the procedure for intravitreal injection. Therefore, we believe our products could be incorporated into retina specialists’ standard medical practice.
We believe suprachoroidal administration may further enhance the value proposition of ocular gene therapy by potentially improving safety and expanding access. We are dedicating some of our resources toward development of therapeutics using this approach and are exploring non-viral gene therapies in preclinical studies both alone and in collaborations with an academic center and gene therapy companies.
Avoid risks of vitrectomy (surgery)
Avoid risks of retinotomy, subretinal injection, and macular detachment
Deliver larger genes using non-viral vectors
Convert gene therapy into an office-based procedure
Provide potentially broader retinal coverage
Enhance patient access
In preclinical studies conducted independently and through collaborations with both an academic center and gene therapy companies, we have observed that suprachoroidal injection can administer both viral and non-viral gene therapy. Using marker genes like green fluorescent protein and luciferase in both rabbits and non-human primates, gene therapy was delivered with our suprachoroidal injection to achieve expression in the retina and choroid.
Inherited retinal diseases, or IRDs, such as Stargardt disease and Usher syndrome, represent some of the most challenging diseases that ophthalmologists encounter. They cause progressive, relentless vision loss due to changes in genes critical to the survival of photoreceptors and RPE cells, yet delivery of therapeutics to these cells is challenging.
In preclinical animal studies from which data was presented at the American Academy of Ophthalmology 2019 Annual Meeting in October 2019, the suprachoroidal injection of luciferase DNA nanoparticles (DNPs), in rabbits produced activity comparable to that seen from subretinal injections of luciferase DNPs. In these studies, SCS injections of DNPs were generally well tolerated across both rabbits and non-human primates, and no significant abnormalities were observed on ophthalmic exams. DNPs can also transfer large genes at potentially higher doses without the risks of subretinal surgery, which may allow for gene therapy in some of the most common IRDs.