Onpattro (patisiran)
An approved treatment for ATTR Amyloidosis.
The same compound appears under different names depending on the context. Here is how to identify Patisiran wherever you encounter it, plus the key facts at a glance.
- Generic name
- Patisiran
- Brand name
- Onpattro
- Development code
- ALN-TTR02
- Drug class
- siRNA (small interfering RNA)
- Manufacturer
- Alnylam Pharmaceuticals
- How it's taken
- Patisiran is given as an intravenous infusion (into a vein) every 3 weeks.
The first RNA interference therapy ever approved. Given by IV infusion every 3 weeks, it sharply lowers the liver's production of transthyretin, the protein that misfolds and damages nerves and organs.
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Where Patisiran fits
First-in-class RNAi therapy for hereditary ATTR amyloidosis with polyneuropathy. Often considered for patients with progressive neuropathy, alongside tafamidis (which targets cardiomyopathy).
How Patisiran works
Patisiran blocks your body's ability to make a harmful protein called TTR (transthyretin). It uses special fatty bubbles (nanoparticles) to deliver the blocker directly to liver cells, which are the main factories making this toxic protein. The drug silences the genetic instructions for making TTR before the protein is even produced.
Mechanism: RNA interference therapy that silences TTR gene expression
Side effects and safety
The most common side effects were upper respiratory tract infections and infusion-related reactions. Infusion reactions happened in 19% of patients in the main trial and can include flushing, shortness of breath, chest pain, fainting, rash, a fast heartbeat or facial swelling. Severe drops in blood pressure have also been reported. Patisiran lowers vitamin A levels, so a daily vitamin A supplement at the recommended daily allowance (not higher) is advised, and you should see an eye doctor if you notice night vision problems. Tell your care team right away if you feel unwell during an infusion.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Patisiran
Patisiran is given as an intravenous infusion (into a vein) every 3 weeks. Each infusion takes about 80 minutes, and premedicines are given at least 60 minutes before it starts. These premedicines are a steroid, acetaminophen and 2 antihistamines (an H1 blocker and an H2 blocker), and they lower the risk of infusion reactions. The dose is based on body weight: 0.3 mg per kg every 3 weeks for people under 100 kg (about 220 pounds), and 30 mg for people 100 kg or more. Infusions are given by a healthcare professional, usually at an infusion center or doctor's office. Some patients can get them at home from a visiting nurse if their doctor recommends it and their insurance covers it.
Availability and cost
Only available as the brand-name product.
First-of-its-kind RNA interference therapy encapsulated in lipid nanoparticles, requiring IV infusion every 3 weeks. Orphan drug for a rare genetic condition with a small global patient population.
Help paying for Onpattro
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
The Alnylam Assist Copay Program covers certain out-of-pocket costs for eligible commercially insured patients. Not for Medicare, Medicaid or other government insurance.
For: private insurance · source - Bridge or quick-start supply
Programs may help if you have a delay or change in insurance coverage; a Case Manager checks eligibility after a Start Form.
The official page does not say who qualifies. Ask the program. · source - Free medicine program
The Alnylam Assist Patient Assistance Program provides treatment at no cost for eligible patients, mainly those who are uninsured.
For: no insurance · source - Insurance and case manager help
After your doctor submits a Start Form, a Case Manager contacts you within 2 business days with a summary of your insurance benefits.
For: private insurance, Medicare, Medicaid, TRICARE, no insurance, underinsured · source
Good to know: Most services start when your doctor submits the Alnylam Assist Start Form. Alnylam can also point uninsured or underinsured patients to independent foundations.
- From a charity · HealthWell FoundationAmyloidosis fundOpen
Pays for: Copays, premiums or other treatment costs.
- From a charity · HealthWell FoundationCardiomyopathy (Medicare Access) fundOpen
Pays for: Copays, premiums or other treatment costs. Medicare patients only.
- From a charity · NORD RareCareAmyloidosis Medical Assistance fundOpen
Pays for: Medical and medication costs.
The foundation says: “Accepting Applications” - From a charity · NORD RareCareAmyloidosis Premium Copay Assistance fundOpen
Pays for: Insurance premiums and copays.
The foundation says: “Accepting Applications” - From a charity · TotalAssist (formerly PAN Foundation)Amyloidosis fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $5,500 per year. Requires Medicare, Medicaid or TRICARE.
- From a charity · The Assistance FundAmyloidosis fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
Clinical trial results
FDA approved patisiran on August 10, 2018, based on the APOLLO trial, which showed statistically significant improvement in neuropathy (nerve damage) and quality of life for people with hereditary ATTR amyloidosis. It was the first RNA interference (RNAi) drug ever approved in the United States.
Development history
Patisiran was developed by Alnylam Pharmaceuticals and represented a revolutionary breakthrough as the first RNA interference (RNAi) therapy approved by the FDA in 2018 for hereditary ATTR with polyneuropathy, marking a new era in treating genetic diseases.
Explore ATTR Amyloidosis trials
Other ATTR Amyloidosis treatments
Patisiran in Trial Friend News and Guides
Common questions about Patisiran
▸What is Patisiran (Onpattro)?
The first RNA interference therapy ever approved. Given by IV infusion every 3 weeks, it sharply lowers the liver's production of transthyretin, the protein that misfolds and damages nerves and organs.
▸How does Patisiran work?
Patisiran blocks your body's ability to make a harmful protein called TTR (transthyretin). It uses special fatty bubbles (nanoparticles) to deliver the blocker directly to liver cells, which are the main factories making this toxic protein. The drug silences the genetic instructions for making TTR before the protein is even produced.
▸What are the side effects of Patisiran?
The most common side effects were upper respiratory tract infections and infusion-related reactions. Infusion reactions happened in 19% of patients in the main trial and can include flushing, shortness of breath, chest pain, fainting, rash, a fast heartbeat or facial swelling. Severe drops in blood pressure have also been reported. Patisiran lowers vitamin A levels, so a daily vitamin A supplement at the recommended daily allowance (not higher) is advised, and you should see an eye doctor if you notice night vision problems. Tell your care team right away if you feel unwell during an infusion.
▸How is Patisiran taken?
Patisiran is given as an intravenous infusion (into a vein) every 3 weeks. Each infusion takes about 80 minutes, and premedicines are given at least 60 minutes before it starts. These premedicines are a steroid, acetaminophen and 2 antihistamines (an H1 blocker and an H2 blocker), and they lower the risk of infusion reactions. The dose is based on body weight: 0.3 mg per kg every 3 weeks for people under 100 kg (about 220 pounds), and 30 mg for people 100 kg or more. Infusions are given by a healthcare professional, usually at an infusion center or doctor's office. Some patients can get them at home from a visiting nurse if their doctor recommends it and their insurance covers it.
▸Is Patisiran FDA approved?
Yes, Patisiran (Onpattro) is FDA approved (2018) for the treatment of ATTR Amyloidosis.
▸How does patisiran compare to tafamidis?
Patisiran and tafamidis work through fundamentally different mechanisms. Patisiran uses RNA interference to sharply cut how much transthyretin (TTR) protein the liver makes, reducing circulating TTR levels by about 80%. Tafamidis stabilizes the TTR protein in its normal shape to prevent misfolding. Patisiran is approved only for hereditary ATTR with polyneuropathy (nerve damage), while tafamidis was initially approved for ATTR cardiomyopathy (heart damage). The choice between them often depends on which organ system is most affected.
▸What was groundbreaking about patisiran's approval?
Patisiran was the first RNA interference (RNAi) therapy ever approved by the FDA, in August 2018. This was a landmark moment not just for ATTR amyloidosis but for all of medicine, as it proved that RNAi technology could work as a viable treatment approach. The approval validated decades of research into RNAi therapeutics and opened the door for subsequent RNAi drugs across many diseases.
▸Why does patisiran require premedication?
Before each patisiran infusion, patients receive a corticosteroid, acetaminophen, an H1 blocker (like diphenhydramine), and an H2 blocker (like famotidine) to reduce the risk of infusion-related reactions. Infusion reactions are a known side effect of patisiran, and premedication helps prevent symptoms like flushing, back pain, nausea, and abdominal pain during or shortly after the infusion.
▸How often do I need patisiran infusions?
Patisiran is given as an intravenous infusion every 3 weeks. Each infusion takes approximately 80 minutes. Infusions are given by a healthcare professional, usually at an infusion center or doctor's office (or at home for some patients), and treatment continues long term to keep TTR levels low. Patients who switch to vutrisiran (Amvuttra) can reduce their treatment frequency to once every 3 months with a subcutaneous injection instead.
▸Do I need to take vitamin A supplements with patisiran?
Your doctor will likely recommend vitamin A supplementation while on patisiran. The TTR protein normally transports vitamin A (retinol) in the blood, so reducing TTR levels with patisiran can lower vitamin A levels. The label advises a daily vitamin A supplement at the recommended daily allowance. Do not take more than that to try to bring blood levels back to normal, because blood tests will stay low on patisiran even when the body has enough.
▸Can patisiran help with ATTR cardiomyopathy?
Patisiran is FDA-approved only for hereditary ATTR with polyneuropathy. The APOLLO-B trial tested it in ATTR cardiomyopathy and showed a significant difference from placebo on a 6-minute walk test at 12 months. But in October 2023 the FDA declined to approve patisiran for ATTR cardiomyopathy, saying the benefit had not been shown to be clinically meaningful, and Alnylam stopped seeking that use in the U.S. However, the newer drug vutrisiran (Amvuttra) received FDA approval for ATTR cardiomyopathy in March 2025 based on the HELIOS-B trial. For patients with mainly heart involvement, approved options include tafamidis, acoramidis (Attruby) and vutrisiran.