E2 - Other Nonviral Delivery (including lipid nanoparticles and exosomes)
764: Engineered Ribonucleoproteins (eRNPs) for Non-Viral In Vivo Delivery of Gene Editors to Treat Ophthalmic Disorders
Type: Poster Session
Poster Board Number: 764
Presentation Details
Session Title: Wednesday Posters: Other Nonviral Delivery
Genome editing technologies offer great potential as durable therapies for a myriad of diseases, including many inherited disorders previously deemed untreatable. The recent approval of ex vivo gene editing therapy for blood disorders showcases the immense promise of this transformative technology while underscoring the need to develop in vivo gene editors to enable application expansion. Current in vivo delivery approaches for gene editors, such as AAV, face multiple challenges, including pre-existing immunity, capsid-induced inflammation, persistent expression of nucleases, and complexity of manufacturing.
Here we describe a new class of single administration genomic medicine, engineered RNPs (eRNPs). eRNPs are non-viral, non-encapsulated biologics designed for safe localized in vivo gene editing. These protein-RNA constructs are a scaffold of Cas nuclease fused with cell-penetrating and nuclear-localizing peptide sequences, with or without a deaminase domain, and complexed with a single guide RNA. Highlighting the modular nature of the protein scaffold, we illustrate the ability to generate bespoke eRNPs tailored to introduce indels, excise exons, or perform base editing for selected genetic lesions.
Inherited retinal disorders (IRDs) represent a class of genetic disorders with high unmet need. eRNPs are particularly well suited for subretinal administration, which enables direct delivery to retinal pigmented epithelial (RPE) cells or photoreceptors. We demonstrate that eRNPs delivered by subretinal injection are highly efficient at introducing indels in RPE and retina in wild-type, transgenic reporter, and functional mouse models. In an Ai14 tdTomato reporter model we observed high focal tdTomato signal in the retinal pigment epithelium (RPE). We demonstrate editing efficiencies are biologically functional by targeting the wild-type allele in KCNJ13+/W53X mice, which resulted in near complete ablation of electroretinogram c-wave. We further show that eRNPs with engineered adenine deaminase domains mediate efficient base editing in the retina and RPE of wild-type mice.
Taken together, these data suggest the highly modular biologic approach of eRNPs opens a new path for treating a wide range of IRDs and ocular diseases with tremendous unmet medical need.
Rina Mepani1, Aaron Cantor1, Pawan Shahi2,3, Spencer Wei1, Vihasi Jani1, Kory Melton1, Prachi Khekare1, Suhani Gupta1, Jonathan Wang1, Peter Otoupal1, Jack Walleshauser1, Benjamin Gowen1, Weng In Leong1, Krishanu Saha2,4, Adam Silverman1, Bikash Pattnaik2,3, Mary Haak-Frendscho1
1Spotlight Therapeutics, Hayward, CA,2McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI,3Department of Pediatrics, University of Wisconsin-Madison, Madison, WI,4Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI"
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