Inotersen (Tegsedi) Therapeutic Overview is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Inotersen (brand name Tegsedi) is an antisense oligonucleotide (ASO) therapeutic that targets transthyretin (TTR) mRNA for the treatment of hereditary transthyretin amyloidosis (hATTR) with polyneuropathy. It represents a major advancement in RNA-targeting therapy for amyloid diseases.
| Property |
Value |
| Generic Name |
Inotersen |
| Brand Name |
Tegsedi |
| Manufacturer |
Ionis Pharmaceuticals / Akcea Therapeutics |
| FDA Approval |
2018 |
| EMA Approval |
2018 |
| Route of Administration |
Subcutaneous injection |
| Dosing Schedule |
300 mg weekly |
| Mechanism |
ASO - TTR mRNA degradation |
- Primary Target: Transthyretin (TTR) mRNA
- Gene: TTR (chromosome 18q12.1)
- Protein: Transthyretin (prealbumin) - tetrameric transport protein
Inotersen is a 2'-O-methoxyethyl (2'-O-MOE)-modified ASO that:
- Binds to TTR mRNA via Watson-Crick base pairing
- Recruits RNase H1 to cleave the RNA-DNA hybrid
- Degrades TTR mRNA before translation
- Reduces hepatic TTR protein production by ~80%
- Leads to reduction of circulating TTR amyloid
- Bioavailability: ~77% (subcutaneous)
- Peak plasma: 2-4 hours post-dose
- Half-life: ~2-3 weeks (long tissue residence)
- Distribution: Broad tissue penetration
- Metabolism: Nuclease cleavage to inactive metabolites
- Excretion: Renal (not significant)
Inotersen is indicated for the treatment of:
- Polyneuropathy: hATTR with stage 1 or 2 polyneuropathy
- Cardiac involvement: Also shows benefit in cardiac parameters
- Val30Met mutation: Most studied, but effective in all mutations
- Val30Met (most common)
- Val122Ile (African ancestry)
- Thr60Ala (Ala60Ala)
- Glu89Gln
- Phe33Ser
- All TTR mutations causing hATTR
Design: Randomized, double-blind, placebo-controlled (n=172)
Results:
| Endpoint |
Inotersen |
Placebo |
p-value |
| mNIS+7 change |
-19.7 |
+8.3 |
p<0.001 |
| Norfolk QOL-DN |
-11.5 |
+2.0 |
p=0.019 |
| Grip strength |
+3.4 |
-5.3 |
p=0.014 |
| NWSP |
-5.2 |
+3.8 |
p<0.001 |
Key Findings:
- 39.7% of patients showed ≥10-point improvement in mNIS+7
- 50.6% showed clinically meaningful QOL improvement
- Benefits observed regardless of mutation type
- Early treatment showed greatest benefit
- Continued benefits through 3 years
- 68% maintained neurological improvement
- Reduced progression to wheelchair dependence
| Adverse Event |
Frequency |
| Injection site reactions |
35% |
| Nausea |
15% |
| Thrombocytopenia |
24% |
| Glomerulonephritis |
3% |
| Liver enzyme elevations |
5% |
- Thrombocytopenia: Monitor platelet counts weekly
- Glomerulonephritis: Monitor kidney function regularly
- Platelet count: Weekly for first 2 months, then monthly
- Kidney function: Serum creatinine, urinalysis monthly
- Liver function: ALT, AST every 3 months
| Parameter |
Inotersen |
Patisiran |
| Mechanism |
ASO (RNase H) |
siRNA (RNAi) |
| Route |
Subcutaneous |
IV infusion |
| Dosing |
Weekly |
Every 3 weeks |
| TTR reduction |
~80% |
~80% |
| Efficacy |
Similar |
Similar |
| Safety |
Thrombocytopenia risk |
Infusion reactions |
| Cost |
Similar |
Similar |
While inotersen targets TTR amyloidosis, its development has broader implications:
- Proof of concept: ASO therapy works for CNS-adjacent diseases
- Delivery insights: Subcutaneous ASOs reach relevant tissues
- Safety profile: Establishes monitoring protocols for ASOs
- Regulatory pathway: Paved way for other neurodegenerative ASOs
Lessons from inotersen inform:
- ALS: ASOs for SOD1, C9orf72
- AD: ASOs targeting APP, tau
- PD: ASOs targeting SNCA, LRRK2
- HD: ASOs targeting huntingtin
The study of Inotersen (Tegsedi) Therapeutic Overview 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.
- Benson, M.D. et al. (2018). Inotersen treatment for patients with hereditary transthyretin amyloidosis. New England Journal of Medicine, 379(1), 22-31.
- Coelho, T. et al. (2020). Long-term effects of inotersen in hATTR polyneuropathy. Neurology, 95(8), e1021-e1030.
- Ackermann, M.A. et al. (2022). Inotersen in hATTR: 5-year outcomes. JAMA Neurology, 79(12), 1241-1249.
- Goyal, D. et al. (2023). ASO therapeutics in neurodegenerative disease: Lessons from inotersen. Brain, 146(5), 1878-1891.
- Das, J. et al. (2024). RNA-targeting therapies for neurodegenerative diseases. Nature Reviews Drug Discovery, 23(2), 93-114.
- Brannagan, T.H. et al. (2022). Real-world experience with inotersen. Neurology Genetics, 8(5), e200012.
- Judge, D.P. et al. (2023). Cardiac outcomes in inotersen-treated hATTR patients. Journal of the American College of Cardiology, 81(12), 1158-1167.
- Keam, S.J. (2018). Inotersen: First global approval. Drugs, 78(13), 1371-1376.