In a phase 1–2 dose-escalation trial involving adults with ALS due to
SOD1
mutations who received intrathecal tofersen (an antisense oligonucleotide) or placebo, the levels of mutant SOD1 in the CSF ...were 33 percentage points lower in the highest-dose tofersen group than in the placebo group.
The original version of this paper contained an incorrect primer sequence. In the Methods subsection "Rampage libraries," the text for modification 3 stated that the reverse primer used for library ...indexing was 5'-CAAGCAGAAGACGGCATACGAGATXXXXXXXXGTGACTGGAGT-3'. The correct sequence of the oligonucleotide used is 5'-CAAGCAGAAGACGGCATACGAGATXXXXXXXXGTGACTGGAGTTCAGACGTGTGCTCTTCCGATCT-3'. This error has been corrected in the PDF and HTML versions of the paper.
In this phase 3 trial, among children with later-onset spinal muscular atrophy, those who received nusinersen had improvement in motor-function scores and those who underwent a sham procedure did not.
Phosphorothioates have found their usefulness in the general area of oligonucleotide therapeutic applications. Initially this modification was introduced into the antisense methodology because of the ...nuclease resistance of the phosphorothioate linkage in comparison with that of the phosphate linkage. However, as experimental data accumulated, it was detected that this chemical modification also facilitates cellular uptake and bioavailibity in vivo. Thus, today the majority of therapeutic oligonucleotides contain this modification. This review will discuss the historical development of this modification and present some of its chemical properties where they differ from those of the phosphate group. The antisense application will be discussed in the original context with cleavage of the target mRNA, but other target RNAs such as microRNAs and long noncoding RNAs will also be covered. It continues with applications where the target RNA should not be cleaved. A brief presentation of decoy oligonucleotides will be included, as well as some miscellaneous applications. Cellular uptake is a crucial step for oligonucleotides to reach their target and will be briefly reviewed. Lastly, a most surprising recent observation is the presence of phosphorothioate groups in bacterial DNA where functions still remain to be fully determined.
IMPORTANCE: An unmet need remains for safe and efficacious treatments for Duchenne muscular dystrophy (DMD). To date, there are limited agents available that address the underlying cause of the ...disease. OBJECTIVE: To evaluate the safety, tolerability, and efficacy of viltolarsen, a novel antisense oligonucleotide, in participants with DMD amenable to exon 53 skipping. DESIGN, SETTING, AND PARTICIPANTS: This phase 2 study was a 4-week randomized clinical trial for safety followed by a 20-week open-label treatment period of patients aged 4 to 9 years with DMD amenable to exon 53 skipping. To enroll 16 participants, with 8 participants in each of the 2 dose cohorts, 17 participants were screened. Study enrollment occurred between December 16, 2016, and August 17, 2017, at sites in the US and Canada. Data were collected from December 2016 to February 2018, and data were analyzed from April 2018 to May 2019. INTERVENTIONS: Participants received 40 mg/kg (low dose) or 80 mg/kg (high dose) of viltolarsen administered by weekly intravenous infusion. MAIN OUTCOMES AND MEASURES: Primary outcomes of the trial included safety, tolerability, and de novo dystrophin protein production measured by Western blot in participants’ biceps muscles. Secondary outcomes included additional assessments of dystrophin mRNA and protein production as well as clinical muscle strength and function. RESULTS: Of the 16 included boys with DMD, 15 (94%) were white, and the mean (SD) age was 7.4 (1.8) years. After 20 to 24 weeks of treatment, significant drug-induced dystrophin production was seen in both viltolarsen dose cohorts (40 mg/kg per week: mean range 5.7% 3.2-10.3 of normal; 80 mg/kg per week: mean range 5.9% 1.1-14.4 of normal). Viltolarsen was well tolerated; no treatment-emergent adverse events required dose reduction, interruption, or discontinuation of the study drug. No serious adverse events or deaths occurred during the study. Compared with 65 age-matched and treatment-matched natural history controls, all 16 participants treated with viltolarsen showed significant improvements in timed function tests from baseline, including time to stand from supine (viltolarsen: −0.19 s; control: 0.66 s), time to run/walk 10 m (viltolarsen: 0.23 m/s; control: −0.04 m/s), and 6-minute walk test (viltolarsen: 28.9 m; control: −65.3 m) at the week 25 visit. CONCLUSIONS AND RELEVANCE: Systemic treatment of participants with DMD with viltolarsen induced de novo dystrophin production, and clinical improvement of timed function tests was observed. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02740972
Single-stranded oligonucleotides have been explored as a therapeutic modality for more than 20 years. Only during the last 5 years have single-stranded oligonucleotides become a modality of choice in ...the fields of precision medicine and targeted therapeutics. Recently, there have been a number of development efforts involving this modality that have led to treatments for genetic diseases that were once untreatable. This review highlights key applications of single-stranded oligonucleotides that function in a sequence-dependent manner when applied to modulate precursor (pre-)mRNA splicing, gene expression, and immune pathways. These applications have been used to address diseases that range from neurological to muscular to metabolic, as well as to develop vaccines. The wide range of applications denotes the versatility of single-stranded oligonucleotides as a robust therapeutic platform. The focus of this review is centered on approved single-stranded oligonucleotide therapies and the evolution of oligonucleotide therapeutics into novel applications currently in clinical development.
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Single-stranded oligonucleotide therapeutics represent a platform of targeted and selective medicines that address severe genetic diseases that were once untreatable. Continued advances in chemistry, targeted delivery, and new applications have paved the way for a future in which ASO therapeutics become a common modality to treat genetic diseases and beyond.
Abstract
Using primary melanocytes and HEK293 cells, we found that cAMP signaling accelerates repair of bi- and mono-functional platinum-induced DNA damage. Elevating cAMP signaling either by the ...agonistic MC1R ligand melanocyte stimulating hormone (MSH) or by pharmacologic cAMP induction by forskolin enhanced clearance of intrastrand cisplatin-adducts in melanocytes or MC1R-transfected HEK293 cells. MC1R antagonists human beta-defensin 3 and agouti signaling protein blocked MSH- but not forskolin-mediated enhancement of platinum-induced DNA damage. cAMP-enhanced repair of cisplatin-induced DNA damage was dependent on PKA-mediated phosphorylation of ATR on S435 which promoted ATR’s interaction with the key NER factor xeroderma pigmentosum A (XPA) and facilitated recruitment of an XPA-ATR-pS435 complex to sites of cisplatin DNA damage. Moreover, we developed an oligonucleotide retrieval immunoprecipitation (ORiP) assay using a novel platinated-DNA substrate to establish kinetics of ATR-pS435 and XPA’s associations with cisplatin-damaged DNA. Expression of a non-phosphorylatable ATR-S435A construct or deletion of A kinase-anchoring protein 12 (AKAP12) impeded platinum adduct clearance and prevented cAMP-mediated enhancement of ATR and XPA’s associations with cisplatin-damaged DNA, indicating that ATR phosphorylation at S435 is necessary for cAMP-enhanced repair of platinum-induced damage and protection against cisplatin-induced mutagenesis. These data implicate cAMP signaling as a critical regulator of genomic stability against platinum-induced mutagenesis.
Spinal muscular atrophy (SMA) is a rare autosomal recessive disorder characterized by muscle atrophy and weakness resulting from motor neuron degeneration in the spinal cord and brainstem. It is most ...commonly caused by insufficient levels of survival motor neuron (SMN) protein (which is critical for motor neuron maintenance) secondary to deletions or mutations in the
SMN1
gene. Nusinersen (SPINRAZA™) is a modified antisense oligonucleotide that binds to a specific sequence in the intron, downstream of exon 7 on the pre-messenger ribonucleic acid (pre-mRNA) of the
SMN2
gene. This modulates the splicing of the
SMN2
mRNA transcript to include exon 7, thereby increasing the production of full-length SMN protein. Nusinersen is approved in the USA for intrathecal use in paediatric and adult patients with SMA. Regulatory assessments for nusinersen as a treatment for SMA are underway in the EU and several other countries. This article summarizes the milestones in the development of nusinersen leading to this first approval for SMA in paediatric and adult patients.
Angiopoietin-like 3 (ANGPTL3) inhibits endothelial lipase and lipoprotein lipase. Injection of antisense oligonucleotides targeting
ANGPTL3
messenger RNA effects a reduction of atherogenic ...lipoproteins in humans and mice and a slowing of progression of atherosclerosis in mice.
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