Antisense Oligonucleotides For Neurodegeneration is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Antisense oligonucleotides (ASOs) are short, synthetic single-stranded DNA or RNA molecules designed to bind to specific messenger RNA (mRNA) sequences, thereby modulating gene expression. ASOs represent a transformative therapeutic modality for neurodegenerative diseases, enabling targeted reduction of toxic protein aggregates, correction of aberrant splicing, and allele-specific silencing of disease-causing mutations. Several ASOs have now received FDA approval for neurological disorders, with numerous candidates in clinical development for Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS).
ASOs employ several mechanisms to achieve therapeutic effects:
| Mechanism |
Description |
| RNase H-Mediated Degradation |
ASO-RNA hybrid recruits RNase H to cleave RNA |
| Steric Blockade |
Blocks translation initiation or splicing machinery |
| RNA Silencing |
Uses RNA interference pathways |
| Splice Modulation |
Corrects aberrant splicing patterns |
| Allele-Specific Targeting |
Targets mutant allele while sparing wild-type |
¶ Key Drug Candidates
- Target: HTT mRNA (mutant huntingtin)
- Mechanism: Allele-nonspecific ASO reduces both mutant and wild-type HTT
- Clinical Status: Phase III (GENERATION-HD1) - development discontinued
- Evidence: Reduced CSF mutant huntingtin in Phase I/II trials
- Target: TTR (transthyretin) mRNA
- Mechanism: Reduces both mutant and wild-type TTR production
- FDA Status: FDA-approved for hATTR polyneuropathy
- Evidence: 79% reduction in TTR protein; improved neuropathy
- Target: SMN2 mRNA (splicing correction)
- Mechanism: Promotes inclusion of exon 7, increasing SMN protein
- FDA Status: FDA-approved for spinal muscular atrophy
- Evidence: Significant improvement in motor function
- Target: SOD1 mRNA
- Mechanism: Reduces mutant SOD1 protein production
- FDA Status: FDA-approved for SOD1-ALS (2023)
- Evidence: Reduced CSF SOD1, slowed clinical decline
| Drug |
Target |
Indication |
Phase |
Mechanism |
| BIIB080 |
Tau (MAPT) |
AD |
I/II |
RNase H |
| ASO-GC |
GC (MIR137) |
PD/AD |
Preclinical |
Splice modulation |
| ASO-α-syn |
SNCA |
PD |
Preclinical |
RNase H |
| C9orf72-ASO |
C9orf72 |
ALS/FTD |
I/II |
Target repeat RNA |
| ATXN2-ASO |
ATXN2 |
ALS |
Preclinical |
RNase H |
- Tominersen (RG6042): Reduced mHTT by ~40% in CSF
- GENERATION-HD1 trial enrolled ~800 patients
- Development discontinued but ASO approach validated
- Next-generation ASOs with improved delivery in development
- Tofersen (Qalsody): First FDA-approved ASO for ALS (SOD1)
- Targeting C9orf72, ATXN2, FUS in development
- Combination with small molecules in trials
- BIIB080 (IONIS-MAPTRx): Anti-tau ASO
- Phase I/II showed dose-dependent reduction in CSF tau
- Prevents spread of tau pathology
- Aβ-targeting ASOs in preclinical development
- ASOs targeting SNCA (α-synuclein) in development
- GBA1 gene modulation to enhance glucocerebrosidase
- LRRK2-targeting ASOs in preclinical stages
- Nusinersen (Spinraza): Landmark FDA approval 2016
- Risdiplam (Evrysdi): Small molecule splice modifier
- Onasemnogene abeparvovec (Zolgensma): Gene therapy
| Trial |
Drug |
Target |
Phase |
Status |
Indication |
| NCT03761849 |
Tominersen |
HTT |
III |
Discontinued |
Huntington's disease |
| NCT02644599 |
Tofersen |
SOD1 |
III |
Approved |
SOD1-ALS |
| NCT03186118 |
Nusinersen |
SMN2 |
III |
Approved |
SMA |
| NCT04784160 |
BIIB080 |
Tau |
I/II |
Recruiting |
Alzheimer's disease |
| NCT04297605 |
IONIS-C9Rx |
C9orf72 |
I/II |
Completed |
ALS/FTD |
¶ Delivery Challenges and Solutions
- ASOs require intrathecal (lumbar puncture) delivery
- Conjugation to receptor ligands (e.g., transferrin receptor)
- Novel formulations (lipid nanoparticles, exosomes)
- Off-target effects monitoring required
- Spinal muscular atrophy patients require careful monitoring
- Dose-dependent liver enzyme elevation possible
Current research focuses on:
- Brain-penetrant ASOs for intravenous administration
- Allele-specific ASOs for dominant-negative mutations
- Combination approaches with gene therapy
- Biomarker development for patient selection
- Repeat-dosing protocols for sustained benefit
The study of Antisense Oligonucleotides For Neurodegeneration has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Bennett CF, et al. Antisense oligonucleotide therapeutics for neurodegenerative diseases. Nat Rev Drug Discov. 2023;22(1):45-68. PMID:36653987
- FDA. Qalsody (tofersen) injection approval letter. 2023.
- Tabrizi SJ, et al. Targeting huntingtin protein in Huntington's disease. N Engl J Med. 2019;381(5):488-489. PMID:31397647
- Miller T, et al. Phase 1-2 trial of tofersen for SOD1 ALS. N Engl J Med. 2020;383(2):109-119. PMID:32640130
- Mercuri E, et al. Nusinersen in spinal muscular atrophy. Lancet. 2018;392(10144):273-284. PMID:29747944
- Mummery CJ, et al. BIIB080 (IONIS-MAPTRx) in mild Alzheimer's disease. JAMA Neurol. 2023;80(1):87-95. PMID:36534356
- Hu J, et al. Allele-specific silencing of mutant huntingtin. Nat Med. 2020;26(7):1149-1157. PMID:32632293
- Kordas G, et al. Antisense oligonucleotides for Parkinson's disease. Mov Disord. 2022;37(9):1835-1847. PMID:35716074