in pictures and a few words
What it is and why it matters
Vutrisiran is an injection once every three months for adults with transthyretin amyloidosis. In this disease one blood protein falls apart, and its fragments settle in the heart and nerves.
- The injection is given under the skin — four times a year
- Approved first for the hereditary form affecting the nerves, then for heart involvement
What goes wrong in this disease
The blood has a carrier protein. In this disease it loses its stability and falls apart into pieces.
- The pieces stick together into fibres
- The fibres are deposited in the heart and nerves
How the drug switches the protein off
Stabiliser tablets keep the protein from falling apart. Vutrisiran acts earlier: it stops the liver from making this protein.
- The cell keeps a blueprint of the protein and makes working copies from it
- The drug tags the copies for destruction: the blueprint is intact, the protein isn’t built
- There is much less of the protein — nothing left to fall apart
Why one injection every three months
The drug carries an “address” that liver cells recognise. They take the drug up by themselves.
- This protein is made mainly in the liver — the drug goes exactly there
- So one injection every three months is enough, with no drips and no hospital
Heart involvement: they lived longer
In a large study, adults with heart involvement died less often on the injections than on a placebo.
- Deaths and repeat heart and blood-vessel problems, counted together, were also fewer
- This is an effect on how long people live, not just on how they feel
Tested in people. Tested in people: a large study in adults with heart involvement in this disease.
Strength is better preserved
Strength for everyday activities was better preserved: in six minutes of walking, people on the injections covered more distance than on a placebo.
- They also rated their wellbeing and quality of life better
Tested in people. Tested in people: in the same study in adults with heart involvement.
With one of the stabiliser tablets
Some people in the study were already taking one of the stabiliser tablets. They benefited from the injections too.
- Whether this pairing is right for you is for a cardiologist to decide
Vitamin A — under a doctor’s watch
This protein also carries vitamin A. When there is less of the protein, there is also less vitamin A in the blood.
- Thyroid hormones are not noticeably affected — they have other carriers
Important. Take vitamin A at the dose your doctor prescribes. If you start seeing worse at dusk, tell your doctor.
Who should see a doctor first
Treatment is started only once the diagnosis is confirmed — after a special scan or a genetic test, not on suspicion.
- Not suitable for another type of amyloidosis — light-chain: that is a different disease
- The injection does not replace the main treatment of heart failure
Important. The injection is not for those who aren’t ready for regular check-ups: checks of the heart and vitamin A are part of treatment.
In one sentence
An injection every three months stops the liver from making the protein whose fragments settle in the heart and nerves — and people with heart involvement in the study lived longer.
- The earlier the diagnosis, the more healthy tissue can be protected
Key points
Vutrisiran (Amvuttra) is an injection every three months for adults with transthyretin amyloidosis: it switches off production of transthyretin in the liver, lowering its level by roughly 80%.
| Situation | How it helps | What human studies showed |
|---|---|---|
| Amyloid cardiomyopathy | lowers the risk of death from any cause together with recurrent cardiovascular events | HELIOS-B (NEJM, 2025), 655 patients: hazard ratio 0.72 (95% CI 0.56–0.93; p=0.01) [1] |
| Survival in cardiomyopathy | death from any cause 35% lower | through 42 months hazard ratio 0.65 (95% CI 0.46–0.90; p=0.01) [1] |
| Walking and quality of life in cardiomyopathy | function is better preserved | six-minute walk test — 26.5 m difference favouring the drug; KCCQ questionnaire — 5.8 points (both p<0.001) [1] |
| Alongside a stabiliser | the benefit holds in patients taking tafamidis | about 40% of participants were already taking tafamidis, and adding vutrisiran benefited them too [1] |
| Polyneuropathy in the hereditary form | the first indication, since 2022 | — |
How it helps
Two ways to solve one problem
In transthyretin amyloidosis the transport protein transthyretin loses stability, falls apart, and the loose parts clump into amyloid fibrils that deposit in the heart and nerves.
The second is not to produce the protein at all. No protein, nothing to fall apart. That is vutrisiran's route.
| Stabilisers (tafamidis, acoramidis) | Vutrisiran | |
|---|---|---|
| What they do | Hold existing protein together | Prevent it being made |
| Where they act | In the blood | In liver cells |
| Form | Daily tablets | Injection every 3 months |
| Reduction in transthyretin level | Minimal | About 80% |
How a gene is silenced
A gene is a blueprint. To build a protein from it, the cell first makes a working copy — messenger RNA — and assembly runs off that copy.
A small interfering RNA is a short fragment that recognises a specific copy and marks it for destruction. The blueprint stays untouched, but the working copies never reach the assembly floor, and the protein is not made.
The mechanism was not invented: cells use RNA interference to defend against viruses. Medicine merely learned to aim it at a chosen gene.
Delivery was a separate engineering problem. A carbohydrate address, GalNAc, is attached to the molecule, and liver cells actively take up anything carrying it. Transthyretin is produced chiefly by the liver, so the targeting lands precisely on target — and makes one injection every three months enough.
What the trial showed
▸HELIOS-B (NEJM, 2025) — 655 patients with transthyretin amyloid cardiomyopathy [1]. The key figure is death from any cause: a 35% reduction means the drug affects not only measurements and wellbeing but how long a person lives. In chronic-disease trials that difference is far from routinely achieved.
▸HELIOS-A (Amyloid, 2023) — the trial in the hereditary form with polyneuropathy, on which the drug's first indication rests [2].
How it is given
A subcutaneous injection every three months — four injections a year, with no infusions and no hospital visit.
Who should see a doctor first
Vitamin A
Transthyretin carries thyroid hormone and vitamin A. When its level falls by 80%, vitamin A transport suffers.
Thyroid hormones are not noticeably affected: thyroxine has other carriers. But vitamin A levels genuinely drop, so patients on drugs of this class are prescribed vitamin A at a dose their doctor specifies, and complaints related to night vision are given particular attention.
Who it is not for
▸Patients with light-chain amyloidosis: a different disease with different treatment. ▸Anyone without a confirmed diagnosis — treatment begins after scintigraphy or genetic confirmation, not on suspicion. ▸As a replacement for baseline heart failure therapy. ▸Anyone unwilling to attend regular follow-up: monitoring vitamin A and cardiac status is part of the treatment.
Bottom line
▸A different level of intervention: not holding the protein together but preventing its production — about an 80% reduction in transthyretin. ▸An effect on survival is demonstrated: 35% lower death from any cause through 42 months. ▸Early diagnosis decides: the earlier the diagnosis, the more intact tissue can be protected.
Treatment can be discussed at a consultation; the drug can be ordered here.
References
1. Fontana M, et al. Vutrisiran in Patients with Transthyretin Amyloidosis with Cardiomyopathy. N Engl J Med. 2025;392(1):33–44. PMID 39213194
2. Adams D, et al. Efficacy and safety of vutrisiran for patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy: a randomized clinical trial. Amyloid. 2023;30(1):1–9. PMID 35875890
3. Gillmore JD, et al. Efficacy and Safety of Acoramidis in Transthyretin Amyloid Cardiomyopathy. N Engl J Med. 2024;390(2):132–142. PMID 38197816
4. AMVUTTRA (vutrisiran) — US Prescribing Information, Alnylam Pharmaceuticals.
Caveats
What cannot be claimed yet:
▸That it is better than stabilisers — no head-to-head trial of vutrisiran against tafamidis or acoramidis has been run. ▸That it dissolves deposited amyloid: it cuts off the supply of new material, nothing more. Stabilisers do not remove it either. ▸That combining with a stabiliser is right for everyone — data on combined use exist, but that is not a general rule. ▸What the consequences of an 80% reduction in transthyretin over many years are — observation so far is measured in years, not decades.
This material is for information only and does not replace a consultation with a doctor.
Key facts
- Vutrisiran (brand name Amvuttra, Alnylam) is a small interfering RNA therapeutic: it suppresses production of transthyretin in the liver and lowers its level by roughly 80%.
- It is given subcutaneously once every three months — four injections a year, with no infusions and no hospital visit. The FDA approved it in June 2022 for polyneuropathy in hereditary transthyretin amyloidosis, and in March 2025 extended the indication to amyloid cardiomyopathy.
- HELIOS-B (NEJM, 2025): 655 patients; the risk of death from any cause together with recurrent cardiovascular events fell by 28% (hazard ratio 0.72; 95% CI 0.56–0.93; p=0.01), and death from any cause through 42 months by 35% (hazard ratio 0.65; 95% CI 0.46–0.90; p=0.01).
- Function was better preserved: the difference on the six-minute walk test was 26.5 m and on the KCCQ quality-of-life score 5.8 points (both p<0.001).
- About 40% of participants were already taking tafamidis, and the benefit of adding vutrisiran held for them; adverse events 99% versus 98% on placebo, serious ones 62% versus 67%.
