Tryngolza (olezarsen)
An approved treatment for Familial Chylomicronemia Syndrome.
The same compound appears under different names depending on the context. Here is how to identify Olezarsen wherever you encounter it, plus the key facts at a glance.
- Generic name
- Olezarsen
- Brand name
- Tryngolza
- Development codes
- ISIS 678354, AKCEA-APOCIII-LRx
- Drug class
- ApoC-III-directed antisense oligonucleotide (ASO)
- Manufacturer
- Ionis Pharmaceuticals
- How it's taken
- For FCS, 80 mg is injected under the skin once a month with a single-dose autoinjector, into the belly or the front of the thigh, or the back of the upper arm if a caregiver or healthcare provider gives it.
A once-monthly injection under the skin, given with an autoinjector, approved by the FDA on December 19, 2024 to lower triglycerides in adults with familial chylomicronemia syndrome (FCS), used together with a very low-fat diet. On June 24, 2026 the FDA also approved it to lower triglycerides and the risk of acute pancreatitis in adults with severe hypertriglyceridemia. In its FCS trial, triglycerides fell 43% more than on placebo at 6 months, and fewer people had pancreatitis attacks.
Where Olezarsen fits
The first FDA-approved medicine for FCS, followed by plozasiran (Redemplo) in November 2025. Both lower apoC-III, olezarsen as a monthly antisense injection and plozasiran as an siRNA injection every 3 months, and no head-to-head trial has compared them.
How Olezarsen works
In FCS, lipoprotein lipase, the enzyme that breaks down fat-carrying particles called chylomicrons, does not work properly, so triglycerides often rise above 880 mg/dL and can trigger pancreatitis. ApoC-III is a protein made in the liver that slows the clearance of triglycerides from the blood. Olezarsen is an antisense oligonucleotide, a short strand of genetic material, with sugar tags that deliver it to liver cells, where it binds the instruction molecule (mRNA) for apoC-III so it is broken down. With less apoC-III, the body clears triglycerides faster. In the FCS trial, apoC-III was about 80% lower than on placebo after 12 months.
Mechanism: Antisense oligonucleotide that lowers the liver's production of apolipoprotein C-III (apoC-III), a protein that slows the clearance of triglycerides
Side effects and safety
- Allergic reactions. Can be serious. Stop Tryngolza and get medical help for wheezing, widespread redness, facial swelling or hives. Do not use it again after a serious allergic reaction.
- Liver enzyme increases. Liver enzymes and liver fat can rise, more often at 80 mg. Your doctor may check liver tests before starting or raising the dose.
- Liver tests before starting or raising the dose, and when clinically needed
- Triglycerides when clinically appropriate; the effect can be measured within 3 months
Tryngolza has no boxed warning. It must not be used by people who have had a serious allergic reaction to olezarsen, and allergic reactions with symptoms such as wheezing, widespread redness, facial swelling, hives, chills and muscle aches have been reported. In the FCS trial the most common side effects, against placebo, were injection site reactions (19% against 9%), a drop in platelet count (12% against 4%) and joint pain (9% against 0%), and 7% stopped because of side effects, most often allergic reactions, against none on placebo. Since June 2026 the label also warns about increases in liver enzymes and liver fat, which were more common with the 80 mg dose used for FCS. Blood sugar rose in some people: among FCS patients without diabetes, 52% on olezarsen had signs of high blood sugar against 35% on placebo. LDL cholesterol also rose, though it stayed below 70 mg/dL in 74% of treated patients[1].
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 Olezarsen
For FCS, 80 mg is injected under the skin once a month with a single-dose autoinjector, into the belly or the front of the thigh, or the back of the upper arm if a caregiver or healthcare provider gives it. Take the autoinjector out of the refrigerator 30 minutes before injecting so it reaches room temperature. People with FCS should keep to 20 g of fat or less a day. For severe hypertriglyceridemia the dose is 50 mg a month, which can be raised to 80 mg. A missed dose should be given as soon as possible, then monthly from that date[1].
Availability and cost
Only available as the brand-name product.
Help paying for Tryngolza
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
Ionis Every Step Copay Program: patients with commercial insurance may pay as little as $0 for each fill. Not available to people using Medicare, Medicaid, TRICARE, DoD, VA or any other state or federal government-funded program.
For: private insurance · source - Other support
Ionis Every Step offers other financial support programs for people without insurance or whose insurance does not cover Tryngolza. Terms and conditions apply.
For: no insurance, underinsured · source - Insurance and case manager help
Injection training, regular check-ins and educational resources, including nutrition information, in coordination with the specialty pharmacy.
The official page does not say who qualifies. Ask the program. · source
Good to know: Select option 2 on the support line; hours Monday to Friday, 8 AM to 8 PM ET. Enrollment is online at TRYNGOLZA.com/Enroll.
- From a charity · The Assistance FundFamilial Chylomicronemia Syndrome (FCS) fundOpen
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.”
Access and eligibility
Approved for adults with FCS, whether the diagnosis was confirmed genetically or clinically, as an add-on to diet, and for adults with severe hypertriglyceridemia (triglycerides of 500 mg/dL or higher). Not for people who have had a serious allergic reaction to olezarsen. Safety and effectiveness in children have not been established. The FCS trial required genetically identified FCS and fasting triglycerides of at least 880 mg/dL.
Source: Ionis Every Step for Tryngolza
Access program details are provided for informational purposes and may vary based on insurance coverage, geographic location, and individual circumstances. Confirm current eligibility directly with the manufacturer or your specialty pharmacy.
Clinical trial results
The FCS approval rested on Balance (NCT04568434), which randomized 66 adults with genetically identified FCS and fasting triglycerides of at least 880 mg/dL to olezarsen 80 mg, 50 mg or placebo every 4 weeks for 53 weeks. At 6 months, triglycerides had fallen 30% on 80 mg and risen 12% on placebo, a difference of 43%. Over 12 months, 1 person (5%) on 80 mg had acute pancreatitis against 7 people (30%) on placebo, all of whom had a history of pancreatitis[1][6]. The 2026 severe hypertriglyceridemia approval rested on CORE and CORE2, 2 trials in 1,061 adults in which triglycerides fell 49% to 72% more than on placebo at 6 months and acute pancreatitis events were less frequent[1].
Development history
Ionis developed olezarsen under the codes ISIS 678354 and AKCEA-APOCIII-LRx[7]. The FDA approved it as Tryngolza on December 19, 2024 for adults with FCS, which Ionis called the first FDA-approved treatment for FCS; it had Priority Review, Fast Track, Orphan Drug and Breakthrough Therapy designations[2][4]. On June 24, 2026, the FDA approved a second use, lowering triglycerides and the risk of acute pancreatitis in adults with severe hypertriglyceridemia (triglycerides of 500 mg/dL or higher), along with a 50 mg dose and a new liver enzyme warning[3][5].
Explore Familial Chylomicronemia Syndrome trials
Other Familial Chylomicronemia Syndrome treatments
A very low-fat diet of 20 g of fat a day or less is the foundation of FCS care. Two FDA-approved medicines can be added for adults: olezarsen (Tryngolza), a monthly injection approved in December 2024, and plozasiran (Redemplo), an injection every 3 months approved in November 2025. Both work by lowering apoC-III.
Common questions about Olezarsen
▸What is Olezarsen (Tryngolza)?
A once-monthly injection under the skin, given with an autoinjector, approved by the FDA on December 19, 2024 to lower triglycerides in adults with familial chylomicronemia syndrome (FCS), used together with a very low-fat diet. On June 24, 2026 the FDA also approved it to lower triglycerides and the risk of acute pancreatitis in adults with severe hypertriglyceridemia. In its FCS trial, triglycerides fell 43% more than on placebo at 6 months, and fewer people had pancreatitis attacks.
▸How does Olezarsen work?
In FCS, lipoprotein lipase, the enzyme that breaks down fat-carrying particles called chylomicrons, does not work properly, so triglycerides often rise above 880 mg/dL and can trigger pancreatitis. ApoC-III is a protein made in the liver that slows the clearance of triglycerides from the blood. Olezarsen is an antisense oligonucleotide, a short strand of genetic material, with sugar tags that deliver it to liver cells, where it binds the instruction molecule (mRNA) for apoC-III so it is broken down. With less apoC-III, the body clears triglycerides faster. In the FCS trial, apoC-III was about 80% lower than on placebo after 12 months.
▸What are the side effects of Olezarsen?
Tryngolza has no boxed warning. It must not be used by people who have had a serious allergic reaction to olezarsen, and allergic reactions with symptoms such as wheezing, widespread redness, facial swelling, hives, chills and muscle aches have been reported. In the FCS trial the most common side effects, against placebo, were injection site reactions (19% against 9%), a drop in platelet count (12% against 4%) and joint pain (9% against 0%), and 7% stopped because of side effects, most often allergic reactions, against none on placebo. Since June 2026 the label also warns about increases in liver enzymes and liver fat, which were more common with the 80 mg dose used for FCS. Blood sugar rose in some people: among FCS patients without diabetes, 52% on olezarsen had signs of high blood sugar against 35% on placebo. LDL cholesterol also rose, though it stayed below 70 mg/dL in 74% of treated patients[1].
▸How is Olezarsen taken?
For FCS, 80 mg is injected under the skin once a month with a single-dose autoinjector, into the belly or the front of the thigh, or the back of the upper arm if a caregiver or healthcare provider gives it. Take the autoinjector out of the refrigerator 30 minutes before injecting so it reaches room temperature. People with FCS should keep to 20 g of fat or less a day. For severe hypertriglyceridemia the dose is 50 mg a month, which can be raised to 80 mg. A missed dose should be given as soon as possible, then monthly from that date[1].
▸Is Olezarsen FDA approved?
Yes, Olezarsen (Tryngolza) is FDA approved (2024) for the treatment of Familial Chylomicronemia Syndrome.
▸Is Tryngolza approved for severe hypertriglyceridemia?
Yes. On June 24, 2026 the FDA approved Tryngolza to lower triglycerides and the risk of acute pancreatitis in adults with severe hypertriglyceridemia, meaning triglycerides of 500 mg/dL or higher. The usual dose for that use is 50 mg a month, while the FCS dose is 80 mg a month.
▸How often is Tryngolza injected?
Once a month, with a single-dose autoinjector, into the belly or the front of the thigh. The back of the upper arm can be used if a caregiver or healthcare provider gives the injection.
▸Does Tryngolza lower the risk of pancreatitis in FCS?
In the Balance trial, 1 person (5%) on the 80 mg dose had acute pancreatitis over 12 months against 7 people (30%) on placebo. The FDA's FCS approval is to lower triglycerides; the specific approval to reduce the risk of acute pancreatitis covers severe hypertriglyceridemia, based on 2 larger trials.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine, DailyMed. TRYNGOLZA (olezarsen) injection, for subcutaneous use: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0f51aa8e-8475-8cf9-e063-6394a90a6848
- U.S. Food and Drug Administration · 2024-12-19. NDA 218614 approval letter. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2024/218614Orig1s000ltr.pdf
- U.S. Food and Drug Administration · 2026-06-24. NDA 218614/S-004 supplement approval letter. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2026/218614Orig1s004ltr.pdf
- Ionis Pharmaceuticals · 2024-12-19. TRYNGOLZA (olezarsen) approved in U.S. as first-ever treatment for adults living with familial chylomicronemia syndrome as an adjunct to diet. https://ir.ionis.com/news-releases/news-release-details/tryngolzatm-olezarsen-approved-us-first-ever-treatment-adults
- Ionis Pharmaceuticals · 2026-06-24. TRYNGOLZA (olezarsen) approved by the FDA as the first and only treatment to reduce triglycerides and the risk of acute pancreatitis in patients with severe hypertriglyceridemia (sHTG). https://ir.ionis.com/news-releases/news-release-details/tryngolzar-olezarsen-approved-fda-first-and-only-treatment
- New England Journal of Medicine · 2024. Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome. https://www.nejm.org/doi/full/10.1056/NEJMoa2400201
- ClinicalTrials.gov. A Study of Olezarsen (Formerly Known as AKCEA-APOCIII-LRx) Administered to Patients With Familial Chylomicronemia Syndrome (FCS) (BALANCE). https://clinicaltrials.gov/study/NCT04568434
- Ionis Pharmaceuticals. Access and Support: TRYNGOLZA (olezarsen) for FCS. https://tryngolza.com/fcs/access-and-support/support