PROJECT SUMMARY/ABSTRACT – OVERALL The genome editing community is celebrating the ten-year anniversary of landmark CRISPR papers in 2022. What is notable to many in the field is tremendous technological advances in editing precision and versatility, along with a Nobel Prize and billions of dollars of investment. However, there is a palpable sense that these advances have not been translated into valuable drugs at a sufficient rate. In vivo gene editing still faces substantial challenges, especially when it comes to safety, efficacy, and delivery. While the development of EDIT-101, a viral vector carrying Cas9 to treat a rare retinal disorder (BRILLIANCE trial), provided a clear path to the clinic for a genome editing therapeutic program, this path can be challenging to follow for others in the field interested in developing human therapeutics. Viral strategies have several limitations involving an immune response to vector elements and prolonged expression of the editor for the lifetime of the patient, heightening off-target concerns. Newer editors like base editors cannot be readily packaged into common viral vectors, plus there is a challenging supply chain for viral vector manufacturing. We seek to overcome the limitations with viral delivery systems by using novel nonviral delivery systems termed the Silica NanoCapsule (SNC) and Target Active Gene Editors (TAGE). They can efficiently deliver genome editors to the retina with high efficiency, reaching levels of 10-70% that are among the best for nonviral delivery of editors to the eye and comparable to viral delivery systems. Based on our strong published and preliminary data we propose to develop nonviral gene editing products to treat Best Disease (BD) and Leber Congenital Amaurosis (LCA), two diseases affecting ion channels of the retinal pigment epithelium (i.e., RPE channelopathies). Our team, spanning academia and industry, will pursue the following aims. In Overall Aim 1, we evaluate the clinical readiness of a genome editor targeting a post-mitotic cell through transient, localized, and nonviral delivery. To date, outside of the liver, only viral editors have reached an IND for in vivo editing. Here, we rigorously evaluate the potential of our SNC and TAGE nonviral delivery systems for the treatment of LCA and BD. We invest our most significant effort into the Lead Project 1 that develops a base editor within a SNC. This project will reach an IND within five years and provide synergy for other projects. In Overall Aim 2, we create a platform that can address many rare diseases of the eye by streamlined manufacturing of different guides with a simple pipeline for preclinical testing. In Overall Aim 3, we provide the SCGE Consortium and broader genome editing field a set of regulatory interactions that clarifies development path to the clinic for new gene editing therapies. Finally, through our experience with BD, we expect to learn about the regulatory path in developing somatic cell genome editors for scenarios when no suitable animal model exists. Because the majority of known pathological mutations in the eye have no suitable animal models, sharing this knowledge will have a large impact on subsequent genome editing leads.

PROJECT NARRATIVE – OVERALL Genome editors make targeted changes in the genome and hold great promise in translational research but moving them into investigational new drugs has been slow and challenging. The majority of products in development target the liver or utilize viral vectors. Because these strategies are limiting for many diseases, especially those that affect post-mitotic cells in complex tissues like the eye, the CRISPR Vision Program seeks to develop novel human genome editing therapeutic platforms for transient, localized, and nonviral treatment of multiple inherited retinal disorders, specifically channelopathies affecting the retinal pigment epithelium.