Stereopure oligonucleotides promote USH2A exon skipping for the treatment of Usher syndrome type 2A

Abstract

Purpose : Wave Life Sciences has developed PRISM^TM, our proprietary discovery and drug development platform that enables us to target genetically defined diseases with stereopure oligonucleotides. PRISM combines our unique ability to construct stereopure oligonucleotides with a deep knowledge of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key pharmacological properties. Here, we report the application of PRISM for the development of stereopure exon-skipping oligonucleotides as a potential disease-modifying therapy for Usher syndrome type 2A.

Methods : Stereopure oligonucleotides targeting exon 13 of the USH2A mRNA transcript were generated using PRISM. Exon-skipping was evaluated under gymnotic conditions in vitro in the Y79 human retinoblastoma cell line. Skipping of the target exon was evaluated by qPCR. The size of skipped product was determined by a gel-shift assay evaluating exons 8-17. RNA-Seq analysis was used to detect and quantify RNA junctions and the presence of skipped transcript. Exon skipping was evaluated ex vivo in non-human primate (NHP) and human retina culture systems. In vivo target engagement was evaluated in wild type NHPs and humanized transgenic mice following a single intravitreal injection of stereopure oligonucleotide.

Results : Stereopure oligonucleotides targeting USH2A induced more potent exon skipping relative to a stereorandom Reference oligonucleotide in cultured cells. We used multiple assays to confirm the presence of the skipped transcript. We also show that our stereopure oligonucleotide induced dose-dependent exon skipping in ex vivo NHP and human retinas. Finally, we demonstrate in vivo target engagement in humanized transgenic mice and NHPs following a single intravitreal injection of stereopure oligonucleotide.

Conclusions : These results indicate that stereopure oligonucleotides generated with PRISM potently induce USH2A exon 13 skipping in multiple model systems. These data support further development of stereopure oligonucleotides as a potential treatment for patients with Usher syndrome type 2A.

This is a 2020 ARVO Annual Meeting abstract.