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Nucleic Acids Research Aug 2023Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the central nervous system (CNS). By modulating RNA, they hold the...
Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the central nervous system (CNS). By modulating RNA, they hold the promise of targeting root molecular causes of disease and hold potential to treat myriad CNS disorders. Realization of this potential requires that ASOs must be active in the disease-relevant cells, and ideally, that monitorable biomarkers also reflect ASO activity in these cells. The biodistribution and activity of such centrally delivered ASOs have been deeply characterized in rodent and non-human primate (NHP) models, but usually only in bulk tissue, limiting our understanding of the distribution of ASO activity across individual cells and across diverse CNS cell types. Moreover, in human clinical trials, target engagement is usually monitorable only in a single compartment, CSF. We sought a deeper understanding of how individual cells and cell types contribute to bulk tissue signal in the CNS, and how these are linked to CSF biomarker outcomes. We employed single nucleus transcriptomics on tissue from mice treated with RNase H1 ASOs against Prnp and Malat1 and NHPs treated with an ASO against PRNP. Pharmacologic activity was observed in every cell type, though sometimes with substantial differences in magnitude. Single cell RNA count distributions implied target RNA suppression in every single sequenced cell, rather than intense knockdown in only some cells. Duration of action up to 12 weeks post-dose differed across cell types, being shorter in microglia than in neurons. Suppression in neurons was generally similar to, or more robust than, the bulk tissue. In macaques, PrP in CSF was lowered 40% in conjunction with PRNP knockdown across all cell types including neurons, arguing that a CSF biomarker readout is likely to reflect ASO pharmacodynamic effect in disease-relevant cells in a neuronal disorder. Our results provide a reference dataset for ASO activity distribution in the CNS and establish single nucleus sequencing as a method for evaluating cell type specificity of oligonucleotide therapeutics and other modalities.
Topics: Animals; Mice; Brain; Oligonucleotides; Oligonucleotides, Antisense; RNA; Tissue Distribution; Transcription Factors; Cerebrospinal Fluid; Central Nervous System Diseases
PubMed: 37188501
DOI: 10.1093/nar/gkad371 -
Drugs Apr 2024Eplontersen (Wainua™) is a ligand-conjugated antisense oligonucleotide directed to TTR, which is being developed by Ionis Pharmaceuticals and AstraZeneca for the... (Review)
Review
Eplontersen (Wainua™) is a ligand-conjugated antisense oligonucleotide directed to TTR, which is being developed by Ionis Pharmaceuticals and AstraZeneca for the treatment of TTR-mediated amyloidosis (ATTR). Eplontersen, which is targeted to the liver by a ligand containing three N-acetyl galactosamine residues, binds to wild-type and variant TTR mRNA, thus reducing the levels of circulating TTR protein and amyloid deposition. Subcutaneous eplontersen reduced serum TTR levels, inhibited neuropathy progression and improved health-related quality of life in patients with polyneuropathy of hereditary ATTR (ATTRv-PN; v for variant) in a phase III trial. Based on these results, eplontersen was approved in the USA for the treatment of ATTRv-PN on 21 December 2023 and is currently undergoing regulatory review for a similar indication in the EU, the UK, Switzerland and Canada. Eplontersen is also undergoing phase III development for ATTR cardiomyopathy. This article summarizes the milestones in the development of eplontersen leading to this first approval for ATTRv-PN.
Topics: Humans; Amyloid Neuropathies, Familial; Prealbumin; Drug Approval; Oligonucleotides; Oligonucleotides, Antisense; Quality of Life; Clinical Trials, Phase III as Topic
PubMed: 38413492
DOI: 10.1007/s40265-024-02008-5 -
JCI Insight Aug 2021Angelman syndrome (AS) is a severe neurodevelopmental disorder for which only symptomatic treatment with limited benefits is available. AS is caused by mutations...
Angelman syndrome (AS) is a severe neurodevelopmental disorder for which only symptomatic treatment with limited benefits is available. AS is caused by mutations affecting the maternally inherited ubiquitin protein ligase E3A (UBE3A) gene. Previous studies showed that the silenced paternal Ube3a gene can be activated by targeting the antisense Ube3a-ATS transcript. We investigated antisense oligonucleotide-induced (ASO-induced) Ube3a-ATS degradation and its ability to induce UBE3A reinstatement and rescue of AS phenotypes in an established Ube3a mouse model. We found that a single intracerebroventricular injection of ASOs at postnatal day 1 (P1) or P21 in AS mice resulted in potent and specific UBE3A reinstatement in the brain, with levels up to 74% of WT levels in the cortex and a full rescue of sensitivity to audiogenic seizures. AS mice treated with ASO at P1 also showed rescue of established AS phenotypes, such as open field and forced swim test behaviors, and significant improvement on the reversed rotarod. Hippocampal plasticity of treated AS mice was comparable to WT but not significantly different from PBS-treated AS mice. No rescue was observed for the marble burying and nest building phenotypes. Our findings highlight the promise of ASO-mediated reactivation of UBE3A as a disease-modifying treatment for AS.
Topics: Angelman Syndrome; Animals; Biological Variation, Population; Disease Models, Animal; Gene Expression Profiling; Gene Silencing; Mice; Oligonucleotides, Antisense; Targeted Gene Repair; Treatment Outcome; Ubiquitin-Protein Ligases
PubMed: 34369389
DOI: 10.1172/jci.insight.145991 -
The Lancet. Neurology Mar 2023Myotonic dystrophy type 1 results from an RNA gain-of-function mutation, in which DM1 protein kinase (DMPK) transcripts carrying expanded trinucleotide repeats exert... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Myotonic dystrophy type 1 results from an RNA gain-of-function mutation, in which DM1 protein kinase (DMPK) transcripts carrying expanded trinucleotide repeats exert deleterious effects. Antisense oligonucleotides (ASOs) provide a promising approach to treatment of myotonic dystrophy type 1 because they reduce toxic RNA levels. We aimed to investigate the safety of baliforsen (ISIS 598769), an ASO targeting DMPK mRNA.
METHODS
In this dose-escalation phase 1/2a trial, adults aged 20-55 years with myotonic dystrophy type 1 were enrolled at seven tertiary referral centres in the USA and randomly assigned via an interactive web or phone response system to subcutaneous injections of baliforsen 100 mg, 200 mg, or 300 mg, or placebo (6:2 randomisation at each dose level), or to baliforsen 400 mg or 600 mg, or placebo (10:2 randomisation at each dose level), on days 1, 3, 5, 8, 15, 22, 29, and 36. Sponsor personnel directly involved with the trial, participants, and all study personnel were masked to treatment assignments. The primary outcome measure was safety in all participants who received at least one dose of study drug up to day 134. This trial is registered with ClinicalTrials.gov (NCT02312011), and is complete.
FINDINGS
Between Dec 12, 2014, and Feb 22, 2016, 49 participants were enrolled and randomly assigned to baliforsen 100 mg (n=7, one patient not dosed), 200 mg (n=6), 300 mg (n=6), 400 mg (n=10), 600 mg (n=10), or placebo (n=10). The safety population comprised 48 participants who received at least one dose of study drug. Treatment-emergent adverse events were reported for 36 (95%) of 38 participants assigned to baliforsen and nine (90%) of ten participants assigned to placebo. Aside from injection-site reactions, common treatment-emergent adverse events were headache (baliforsen: ten [26%] of 38 participants; placebo: four [40%] of ten participants), contusion (baliforsen: seven [18%] of 38; placebo: one [10%] of ten), and nausea (baliforsen: six [16%] of 38; placebo: two [20%] of ten). Most adverse events (baliforsen: 425 [86%] of 494; placebo: 62 [85%] of 73) were mild in severity. One participant (baliforsen 600 mg) developed transient thrombocytopenia considered potentially treatment related. Baliforsen concentrations in skeletal muscle increased with dose.
INTERPRETATION
Baliforsen was generally well tolerated. However, skeletal muscle drug concentrations were below levels predicted to achieve substantial target reduction. These results support the further investigation of ASOs as a therapeutic approach for myotonic dystrophy type 1, but suggest improved drug delivery to muscle is needed.
FUNDING
Ionis Pharmaceuticals, Biogen.
Topics: Adult; Humans; Double-Blind Method; Myotonic Dystrophy; Myotonin-Protein Kinase; Oligonucleotides, Antisense; RNA; RNA, Messenger; Treatment Outcome
PubMed: 36804094
DOI: 10.1016/S1474-4422(23)00001-7 -
RNA Biology 2022RNA therapeutics comprise a diverse group of oligonucleotide-based drugs such as antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), and short hairpin...
RNA therapeutics comprise a diverse group of oligonucleotide-based drugs such as antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), and short hairpin RNAs (shRNAs) that can be designed to selectively interact with drug targets currently undruggable with small molecule-based drugs or monoclonal antibodies. Furthermore, RNA-based therapeutics have the potential to modulate entire disease pathways, and thereby represent a new modality with unprecedented potential for generating disease-modifying drugs for a wide variety of human diseases, including central nervous system (CNS) disorders. Here, we describe different strategies for delivering RNA drugs to the CNS and review recent advances in clinical development of ASO drugs and siRNA-based therapeutics for the treatment of neurological diseases and neuromuscular disorders. 2'-MOE: 2'--(2-methoxyethyl); 2'--Me: 2'--methyl; 2'-F: 2'-fluoro; AD: Alzheimer's disease; ALS: Amyotrophic lateral sclerosis; ALSFRS-R: Revised Amyotrophic Lateral Sclerosis Functional Rating Scale; ARC: Antibody siRNA Conjugate; AS: Angelman Syndrome; ASGRP: Asialoglycoprotein receptor; ASO: Antisense oligonucleotide; AxD: Alexander Disease; BBB: Blood brain barrier; Bp: Basepair; CNM: Centronuclear myopathies; CNS: Central Nervous System; CPP: Cell-penetrating Peptide; CSF: Cerebrospinal fluid; DMD: Duchenne muscular dystrophy; DNA: Deoxyribonucleic acid; FAP: Familial amyloid polyneuropathy; FALS: Familial amyotrophic lateral sclerosis; FDA: The United States Food and Drug Administration; GalNAc: N-acetylgalactosamine; GoF: Gain of function; hATTR: Hereditary transthyretin amyloidosis; HD: Huntington's disease; HRQOL: health-related quality of life; ICV: Intracerebroventricular; IT: Intrathecal; LNA: Locked nucleic acid; LoF: Loss of function; mRNA: Messenger RNA; MS: Multiple Sclerosis; MSA: Multiple System Atrophy; NBE: New Biological Entity; NCE: New Chemical Entity; NHP: Nonhuman primate; nt: Nucleotide; PD: Parkinson's disease; PNP: Polyneuropathy; PNS: Peripheral nervous system; PS: Phosphorothioate; RISC: RNA-Induced Silencing Complex; RNA: Ribonucleic acid; RNAi: RNA interference; s.c.: Subcutaneous; siRNA: Small interfering RNA; SMA: Spinal muscular atrophy; SMN: Survival motor neuron; TTR: Transthyretin.
Topics: Animals; Amyloid Neuropathies, Familial; Amyotrophic Lateral Sclerosis; Neuromuscular Diseases; Oligonucleotides, Antisense; Quality of Life; RNA, Messenger; RNA, Small Interfering; United States; Genetic Therapy; Humans; Disease Models, Animal
PubMed: 35482908
DOI: 10.1080/15476286.2022.2066334 -
Proceedings of the National Academy of... Jul 2023Aberrant alternative splicing of mRNAs results in dysregulated gene expression in multiple neurological disorders. Here, we show that hundreds of mRNAs are incorrectly...
Aberrant alternative splicing of mRNAs results in dysregulated gene expression in multiple neurological disorders. Here, we show that hundreds of mRNAs are incorrectly expressed and spliced in white blood cells and brain tissues of individuals with fragile X syndrome (FXS). Surprisingly, the gene is transcribed in >70% of the FXS tissues. In all -expressing FXS tissues, RNA itself is mis-spliced in a CGG expansion-dependent manner to generate the little-known -217 RNA isoform, which is comprised of exon 1 and a pseudo-exon in intron 1. -217 is also expressed in FXS premutation carrier-derived skin fibroblasts and brain tissues. We show that in cells aberrantly expressing mis-spliced , antisense oligonucleotide (ASO) treatment reduces -217, rescues full-length RNA, and restores FMRP (Fragile X Messenger RibonucleoProtein) to normal levels. Notably, gene reactivation in transcriptionally silent FXS cells using 5-aza-2'-deoxycytidine (5-AzadC), which prevents DNA methylation, increases -217 RNA levels but not FMRP. ASO treatment of cells prior to 5-AzadC application rescues full-length expression and restores FMRP. These findings indicate that misregulated RNA-processing events in blood could serve as potent biomarkers for FXS and that in those individuals expressing , ASO treatment may offer a therapeutic approach to mitigate the disorder.
Topics: Humans; Fragile X Syndrome; Trinucleotide Repeat Expansion; Oligonucleotides, Antisense; Decitabine; Fragile X Mental Retardation Protein; Oligonucleotides; RNA
PubMed: 37364131
DOI: 10.1073/pnas.2302534120 -
Cell Jun 2022Spinal muscular atrophy (SMA) is a motor-neuron disease caused by mutations of the SMN1 gene. The human paralog SMN2, whose exon 7 (E7) is predominantly skipped, cannot...
Spinal muscular atrophy (SMA) is a motor-neuron disease caused by mutations of the SMN1 gene. The human paralog SMN2, whose exon 7 (E7) is predominantly skipped, cannot compensate for the lack of SMN1. Nusinersen is an antisense oligonucleotide (ASO) that upregulates E7 inclusion and SMN protein levels by displacing the splicing repressors hnRNPA1/A2 from their target site in intron 7. We show that by promoting transcriptional elongation, the histone deacetylase inhibitor VPA cooperates with a nusinersen-like ASO to promote E7 inclusion. Surprisingly, the ASO promotes the deployment of the silencing histone mark H3K9me2 on the SMN2 gene, creating a roadblock to RNA polymerase II elongation that inhibits E7 inclusion. By removing the roadblock, VPA counteracts the chromatin effects of the ASO, resulting in higher E7 inclusion without large pleiotropic effects. Combined administration of the nusinersen-like ASO and VPA in SMA mice strongly synergizes SMN expression, growth, survival, and neuromuscular function.
Topics: Animals; Chromatin; Exons; Mice; Muscular Atrophy, Spinal; Oligonucleotides, Antisense; RNA Splicing
PubMed: 35688133
DOI: 10.1016/j.cell.2022.04.031 -
Drugs Jul 2020Viltolarsen (Viltepso in Japan) is a phosphorodiamidate morpholino antisense oligonucleotide being developed by Nippon Shinyaku, in collaboration with the National... (Review)
Review
Viltolarsen (Viltepso in Japan) is a phosphorodiamidate morpholino antisense oligonucleotide being developed by Nippon Shinyaku, in collaboration with the National Center of Neurology and Psychiatry (NCNP), for the treatment of Duchenne muscular dystrophy (DMD). Viltolarsen binds to exon 53 of the dystrophin mRNA precursor and restores the amino acid open-reading frame by skipping exon 53, resulting in the production of a shortened dystrophin protein that contains essential functional portions. In March 2020, intravenous viltolarsen received its first global approval in Japan for the treatment of DMD in patients with confirmed deletion of the dystrophin gene that is amenable to exon 53 skipping. Viltolarsen is under regulatory review in the USA and clinical trials continue in the USA, Canada and globally. This article summarizes the milestones in the development of viltolarsen leading to the first approval for DMD.
Topics: Drug Approval; Humans; Molecular Conformation; Muscular Dystrophy, Duchenne; Oligonucleotides; Oligonucleotides, Antisense
PubMed: 32519222
DOI: 10.1007/s40265-020-01339-3 -
Journal of Pharmacokinetics and... Oct 2021Antisense oligonucleotides (ASOs) are promising therapeutic agents for a variety of neurodegenerative and neuromuscular disorders, e.g., Alzheimer's, Parkinson's and...
Antisense oligonucleotides (ASOs) are promising therapeutic agents for a variety of neurodegenerative and neuromuscular disorders, e.g., Alzheimer's, Parkinson's and Huntington's diseases, spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), caused by genetic abnormalities or increased protein accumulation. The blood-brain barrier (BBB) represents a challenge to the delivery of systemically administered ASOs to the relevant sites of action within the central nervous system (CNS). Intrathecal (IT) delivery, in which drugs are administered directly into the cerebrospinal fluid (CSF) space, enables to bypass the BBB. Several IT-administered ASO therapeutics have already demonstrated clinical effect, e.g., nusinersen (SMA) and tofersen (ALS). Due to novelty of IT dosing for ASOs, very limited pharmacokinetic (PK) data is available and only a few modeling reports have been generated. The objective of this work is to advance fundamental understanding of whole-body distribution of IT-administered ASOs. We propose a physiologically-based pharmacokinetic modeling approach to describe the distribution along the neuroaxis based on PK data from non-human primate (NHP) studies. We aim to understand the key processes that drive and limit ASO access to the CNS target tissues. To elucidate the trade-off between parameter identifiability and physiological plausibility of the model, several alternative model structures were chosen and fitted to the NHP data. The model analysis of the NHP data led to important qualitative conclusions that can inform projection to human. In particular, the model predicts that the maximum total exposure in the CNS tissues, including the spinal cord and brain, is achieved within two days after the IT injection, and the maximum amount absorbed by the CNS tissues is about 4% of the administered IT dose. This amount greatly exceeds the CNS exposures delivered by systemic administration of ASOs. Clearance from the CNS is controlled by the rate of transfer from the CNS tissues back to CSF, whereas ASO degradation in tissues is very slow and can be neglected. The model also describes local differences in ASO concentration emerging along the spinal CSF canal. These local concentrations need to be taken into account when scaling the NHP model to human: due to the lengthier human spinal column, inhomogeneity along the spinal CSF may cause even higher gradients and delays potentially limiting ASO access to target CNS tissues.
Topics: Animals; Biological Transport; Blood-Brain Barrier; Central Nervous System; Humans; Injections, Spinal; Oligonucleotides, Antisense; Primates
PubMed: 33991294
DOI: 10.1007/s10928-021-09761-0 -
The New England Journal of Medicine Mar 2022
Topics: Angioedemas, Hereditary; Complement C1 Inhibitor Protein; Humans; Oligonucleotides; Oligonucleotides, Antisense
PubMed: 35294818
DOI: 10.1056/NEJMe2201729