Hunyara, J. L. | Search bioRxiv

bioRxiv2025

Enhanced splicing modulation by NMA-modified antisense oligonucleotides

Aberrant RNA splicing contributes to many human diseases, and splice-switching antisense oligonucleotides (SSOs) are ideally suited as a therapeutic strategy to modulate splicing and restore normal gene expression. Nusinersen (Spinraza) has revolutionized the treatment of spinal muscular atrophy. It is a splice-switching oligonucleotide (SSO) that is modified with 2-O-methoxyethyl (MOE) modifications. Here, we introduce a next-generation ribose modification, 2'-O-[2-(methyl-amino)-2-oxoethyl] (NMA), which enhances the pharmacological properties of SSOs. We identified a long-lasting NMA-modified human candidate SSO, salanersen, that is 3-4-fold more potent than nusinersen in human SMN2 transgenic mice. To evaluate the generality of the NMA chemistry, we applied it to modulation of SCN1A exon 20N splicing, a therapeutic strategy for Dravet syndrome. An NMA-modified SSO is 3.5-fold more potent than STK-001, a MOE-modified SSO currently in clinical trials. Our data establish the NMA chemistry as a broadly applicable ribose modification that markedly improves the pharmacological profile of SSOs, supporting its development as a next-generation platform for splicing modulation therapies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=69 SRC="FIGDIR/small/680653v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@122e426org.highwire.dtl.DTLVardef@1b0a56eorg.highwire.dtl.DTLVardef@3ce4e8org.highwire.dtl.DTLVardef@1d86378_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2025

Therapeutic antisense oligonucleotide mitigates retinal dysfunction in a pig model of CLN3 Batten disease

CLN3 Batten disease is a lethal pediatric autosomal recessive neurodegenerative disease caused by mutations in the CLN3 gene. Typically, the disease manifests as vision loss early in life and progresses to neurological dysfunction and death in young adulthood. Therapeutic development has focused on treating the central nervous system. However, such therapies may not protect against vision loss, which has a significant impact on quality of life. We have shown that a splice-switching antisense oligonucleotide (ASO) delivered to the central nervous system can reduce neurological disease burden in mouse models of CLN3 disease. Here, we report on a similar ASO approach for treating CLN3 Batten disease retinal dysfunction in a pig model of the disease, which is more representative of human vision. A single intravitreal injection of ASO induces robust exon skipping in the retina for up to 12 months. The ASO treatment resulted in higher amplitudes on electroretinograms, suggesting mitigation of retinal dysfunction at early timepoints of disease. One ASO that efficiently induces exon skipping in vivo was well-tolerated and targets a region of CLN3 that is conserved in humans, making it a promising candidate for treating the disease in humans. Our findings demonstrate the potential utility of an ASO-based approach to treat retinal dysfunction in CLN3 Batten disease and generally supports the use of ASOs for treating eye diseases. One Sentence SummarySplice-switching antisense oligonucleotides delivered by intravitreal injection are safe and show efficacy in preventing early retinal dysfunction in a pig model of CLN3 Batten disease.

molecular biology↗