Accelerating the translation of oligonucleotide therapeutics by enhancing delivery

Oligonucleotide therapeutics (ONTs) are poised to ignite a paradigm shift in what constitutes a treatablehuman disease. The FDA approval of life-changing ONTs like Spinraza (Ionis ASO therapy for spinal muscularatrophy) Onpattro (Alnylams siRNA therapy for hATTR amyloidosis) and the mRNA-based COVID-19vaccines from Pfizer and Moderna that saved millions of lives demonstrate the profound potential impact ONTscan have on undruggable diseases. CRISPR-based editing strategies are now entering the clinic with lipidnanoparticle-mediated delivery of mRNA encoding Cas9 variants offering an alternative to problematic viralvectors. Suppressor tRNAs that read through premature stop codons to restore proteins that were lost intranslation are moving towards the clinic. Each of these ONTs faces a shared barrier to broad clinicaltranslation: biological membranes. The large size (5-35 kD) and charged backbone of ONTs severely limitstheir ability to cross the plasma membrane. Even if the plasma membrane is crossed by promoting theendocytosis of the ONT the endosomal membrane remains a highly effective barrier that prevents ONTs fromreaching their targets in the cytosol and nucleus. Estimates are that only 1-3% of the ONT delivered to apatient reaches its target - the delivery stats are dismal for naked ligand-conjugated and LNP-encased ONTs.ONTs tend to accumulate in the liver and most FDA-approved ONTs that are delivered systemically have livertargets. ONT conjugation to GalNAc the ligand for the asialoglycoprotein receptor expressed on hepatocytesimproves delivery 30-fold. Other approved agents rely on local delivery to increase ONT exposure to a levelsufficient to provide clinical value. However not all tissues are suited for local delivery many cell types withthese tissues remain inaccessible to ONTs and local delivery risks infection or damage to the target organ.There is thus a critical unmet need for strategies that improve the delivery of systemically administered ONTsto extrahepatic tissues. Until this need is met a revolution in medical practice ushered in by nucleotide-basedtherapies will remain a dream unrealized. This proposal seeks a small molecule solution to the deliveryproblem. This strategy would be effective for multiple ONT platforms and disease agnostic. By drilling down onrigorous target validation from the outset we hope to initiate a successful drug development program thattakes the most direct path to the clinic. Our lead compounds diverge from status quo potentiators in that theydramatically increase ONT activity without causing endosomal damage an effective but prohibitively toxicmode of action. The expected results would provide a solid foundation for funding a successful leadoptimization program supported by target engagement assays and highlight the diseases most likely to rapidlyrealize the benefits of this approach.