Plozasiran Lowers Triglycerides and Acute Pancreatitis Risk
Updated: 2 days ago
Read and interpreted by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review
Quick Answer: What is plozasiran for severe hypertriglyceridemia?
Plozasiran is a small interfering RNA medicine that targets APOC3 messenger RNA to lower blood triglycerides and reduce the risk of acute pancreatitis in adults with severe hypertriglyceridemia, defined as fasting triglycerides of 500 mg/dL or higher. Seek emergency care for sudden, severe upper abdominal pain, nausea, or vomiting. [1] [2] [3]
Every claim in this article was checked against its sources by two independent AI systems and read by a physician. Last check: 9 November 2026.
What the research says
Plozasiran reduced fasting triglycerides by roughly four-fifths at one year. Across two Phase 3 trials involving 757 adults with severe hypertriglyceridemia, 25 mg of plozasiran given every three months lowered median fasting triglyceride levels by 79% and 81% from baseline to month 12, a placebo-adjusted reduction of 45 and 47 percentage points. (Watts GF et al., New England Journal of Medicine, 2026) [1]
More than nine in ten treated patients dropped below the 500 mg/dL pancreatitis-risk threshold. At 12 months, 91% and 93% of patients receiving plozasiran had a fasting triglyceride level below 500 mg per deciliter (5.6 mmol per liter), compared with 51% and 50% of patients receiving placebo. (Watts GF et al., New England Journal of Medicine, 2026) [1]
Acute pancreatitis was less frequent with plozasiran than with placebo. Adjudicated acute pancreatitis occurred at 1 event per 100 patient-years in the pooled plozasiran groups compared with 5 events per 100 patient-years in the pooled placebo groups, a rate ratio of 0.22. (Watts GF et al., New England Journal of Medicine, 2026) [1]
Key takeaways
Plozasiran targets APOC3 messenger RNA and was given as a 25 mg dose at baseline and months 3, 6, and 9 in two double-blind Phase 3 trials. [1]
Median fasting plasma triglycerides fell by 79% and 81% at month 12 in the plozasiran groups. [1]
Over 90% of plozasiran-treated participants reached fasting triglyceride levels below 500 mg per deciliter at 12 months. [1]
Adjudicated acute pancreatitis occurred at 1 per 100 patient-years with plozasiran versus 5 per 100 patient-years with placebo. [1]
Adverse events during treatment occurred in 73% of patients in both the pooled plozasiran and placebo groups. [1]
What did the plozasiran trials find?
Two double-blind, placebo-controlled trials found that plozasiran lowered median fasting plasma triglyceride levels by 79% and 81% at month 12 and reduced the rate of adjudicated acute pancreatitis compared with placebo in adults with severe hypertriglyceridemia. We reviewed the identically designed Phase 3 trials (SHASTA-3 and SHASTA-4), which randomly assigned 757 adults with severe hypertriglyceridemia in a 2:1 ratio to receive 25 mg of plozasiran or placebo at baseline and at months 3, 6, and 9. [1]
The primary end point was the percent change in the fasting plasma triglyceride level from baseline to month 12. Key secondary end points included the percent change in fasting triglycerides at month 10, achievement of fasting triglycerides below 500 mg per deciliter (5.6 mmol per liter) and below 150 mg per deciliter (1.7 mmol per liter), the percent change in fasting serum triglycerides at month 12 among patients with baseline triglycerides of 880 mg per deciliter or greater, and changes in remnant cholesterol and non-HDL cholesterol. A pooled analysis evaluated adjudicated acute pancreatitis incidence and first-event timing across both trials. [1]
Outcome at month 12 | Plozasiran (25 mg) | Placebo | Difference or effect |
Median change in fasting triglycerides from baseline | -79% and -81% | Not reported in abstract | -45 points (95% CI, -51 to -38) and -47 points (95% CI, -54 to -39) |
Patients with fasting triglycerides below 500 mg/dL (5.6 mmol/L) | 91% and 93% | 51% and 50% | P < 0.001 |
Adjudicated acute pancreatitis (pooled) | 1 per 100 patient-years | 5 per 100 patient-years | Rate ratio 0.22 (P = 0.008) |
Any adverse event during treatment (pooled) | 73% | 73% | No difference |
Source: [1]
What does the abstract not tell you about plozasiran?
The abstract omits the exact baseline triglyceride distributions, the numerical results for several secondary lipid end points, and a breakdown of individual adverse events. In the abstract, we see that 757 adults were enrolled and followed through month 12, which leaves open questions about efficacy and safety beyond one year of treatment. Both trials were funded by the drug's manufacturer, Arrowhead Pharmaceuticals (registered as NCT06347003 and NCT06347016). [1]
The primary outcome of both trials was a laboratory surrogate marker, the percent change in fasting plasma triglycerides at month 12, rather than a clinical event, although adjudicated acute pancreatitis was evaluated as a prespecified pooled analysis. Both the relative and the absolute effect matter: the rate ratio of 0.22 represents a 78% relative reduction, while the absolute rate dropped from 5 events per 100 patient-years with placebo to 1 event per 100 patient-years with plozasiran. [1]
Although the abstract lists key secondary end points, it does not report the numerical results for them. Similarly, it reports that 73% of patients in both pooled groups had adverse events during treatment, without detailing specific side effects, serious adverse event rates, or participant demographics that affect how widely the results apply. [1]
What does this change for patients with severe hypertriglyceridemia?
For adults with severe hypertriglyceridemia, these trial results show that a quarterly 25 mg treatment targeting APOC3 messenger RNA brought fasting triglycerides below 500 mg per deciliter in more than 90% of treated trial participants and lowered the 12-month rate of acute pancreatitis. Severe hypertriglyceridemia is associated with an increased risk of acute pancreatitis, a serious condition that causes sudden, severe upper abdominal pain, nausea, and vomiting and usually means a few days in hospital for intravenous fluids and pain relief. [1] [3]
Standard management of high blood triglycerides starts with diet and lifestyle changes, including limiting added sugars and saturated fats, avoiding alcohol, exercising regularly, and managing conditions such as type 2 diabetes. Conventional medicines such as fibrates, omega-3 fatty acids (fish oil), and statins are commonly used, yet a small number of patients continue to have very high triglyceride levels that resist treatment. If your triglycerides stay above 500 mg per deciliter despite treatment, your doctor may refer you to a specialised lipid clinic, where newer therapies such as the one tested in these trials can be discussed. [1] [2] [4]
What does this change for doctors treating severe hypertriglyceridemia?
For clinicians managing adults with severe hypertriglyceridemia, these two Phase 3 trials provide randomized evidence that inhibiting APOC3 messenger RNA with plozasiran every three months lowers median fasting triglycerides by 79% to 81% at 12 months and reduces adjudicated acute pancreatitis events. A fasting triglyceride level below 500 mg per deciliter (5.6 mmol per liter) was the threshold used in both trials, and levels above it are linked to a higher risk of pancreatitis; 91% to 93% of plozasiran-treated patients reached it at 12 months compared with 50% to 51% on placebo. [1] [2]
When evaluating patients with persistent severe hypertriglyceridemia, clinicians should continue to address secondary causes, such as uncontrolled diabetes, hypothyroidism, kidney or liver disease, alcohol intake, and triglyceride-raising medicines, alongside standard lipid-lowering medications. In patients whose triglycerides remain elevated or who face a high risk of acute pancreatitis, quarterly RNA interference therapy showed an absolute reduction of 4 acute pancreatitis events per 100 patient-years over 12 months of follow-up. [1] [2] [4]
A physician's observation
Dr. Baraa Alnahhal, MD, General Practitioner at Zagazig General Hospital and Alahrar Teaching Hospital, Egypt. Clinical experience, not a study finding.
In my clinics in Zagazig, I see a fasting triglyceride above 500 mg/dL a few times a month. Most of the time the cause is clear: uncontrolled type 2 diabetes, a diet heavy in sugar and refined carbohydrates, a familial pattern in a younger patient, or a medicine or condition such as steroids, hypothyroidism or kidney disease. My first conversation is always the same. Control the diabetes, cut the sugar, refined carbs and alcohol, and start a fibrate or omega-3, usually with a statin, because triglycerides often fall a long way once those are addressed.
I also make sure every one of these patients knows the warning signs of pancreatitis: severe upper abdominal pain and vomiting mean the emergency department, not the pharmacy. A quarterly injection that cuts triglycerides by four-fifths is a big step forward, but for most of my patients it is out of reach for now, so the basics are still the treatment they get.
Conclusion
Data from two Phase 3 trials of 757 adults with severe hypertriglyceridemia show that 25 mg of plozasiran given every three months reduced median fasting triglyceride levels by 79% and 81% at 12 months. Over 90% of patients treated with plozasiran brought their triglycerides below the 500 mg per deciliter risk threshold, and the pooled rate of acute pancreatitis was 1 per 100 patient-years versus 5 per 100 patient-years with placebo. [1]
Overall adverse event rates were 73% in both groups over 12 months, and longer follow-up is still needed. Reviewing the full trial data with a specialist remains essential before making treatment changes. Bring this guide to your next appointment, and explore more heart health guides on Rinnit.com. [1]
FAQ
What is severe hypertriglyceridemia?
Severe hypertriglyceridemia is a lipid disorder in which fasting blood triglyceride levels reach 500 mg per deciliter (5.6 mmol per liter) or higher. Very high triglyceride levels are linked to a higher risk of sudden inflammation of the pancreas, known as acute pancreatitis, and to cardiovascular disease. [1] [2]
What causes severe hypertriglyceridemia?
Severe hypertriglyceridemia is caused by a mix of inherited conditions, medical disorders such as poorly controlled diabetes, hypothyroidism, obesity, or kidney and liver disease, and lifestyle factors such as a high intake of sugar, fat, or alcohol. Certain medicines, including diuretics, steroids, retinoids, beta blockers, estrogen, and some HIV treatments, can also raise blood triglyceride levels. [2] [4]
What are the symptoms of severe hypertriglyceridemia?
Severe hypertriglyceridemia usually causes no symptoms on its own, which is why routine blood lipid testing is needed to detect it. When extremely high triglyceride levels trigger acute pancreatitis, the symptoms are sudden, severe upper abdominal pain, nausea, and vomiting. [2] [3]
How is severe hypertriglyceridemia diagnosed?
Severe hypertriglyceridemia is diagnosed with a blood test called a lipid panel or triglycerides test, usually after fasting for 9 to 12 hours. A fasting result below 150 mg per deciliter is healthy, 200 to 499 mg per deciliter is high, and 500 mg per deciliter or higher is very high. [2]
How is severe hypertriglyceridemia treated?
Severe hypertriglyceridemia is treated with lifestyle changes, such as limiting sugar, refined carbohydrates, saturated fat, and alcohol while increasing physical activity, combined with lipid-lowering medicines such as fibrates, omega-3 fatty acids (fish oil), or statins. Targeted therapies such as plozasiran, which silences APOC3 messenger RNA, have been studied in Phase 3 trials to lower triglycerides and reduce acute pancreatitis risk. [1] [2] [4]
How does plozasiran work in severe hypertriglyceridemia?
Plozasiran is a small interfering RNA therapy that targets APOC3 messenger RNA to lower blood triglyceride levels. In the SHASTA-3 and SHASTA-4 trials, 25 mg of plozasiran given at baseline and months 3, 6, and 9 reduced median fasting triglyceride levels by 79% and 81% at month 12. [1]
How much did plozasiran lower the risk of acute pancreatitis?
Plozasiran reduced the rate of adjudicated acute pancreatitis to 1 event per 100 patient-years, compared with 5 events per 100 patient-years with placebo, across two pooled Phase 3 trials. That difference corresponds to a rate ratio of 0.22 (P = 0.008) over 12 months of follow-up. [1]
When should you seek emergency care for severe hypertriglyceridemia?
Emergency care is needed right away if you develop warning signs of acute pancreatitis: sudden, severe pain in the upper abdomen, persistent nausea, or vomiting. Acute pancreatitis is a serious condition that usually means a few days in hospital for intravenous fluids and pain relief. [3]
Related reading
References
Watts GF, Ballantyne CM, Blanco Echevarria A, et al. Plozasiran for Severe Hypertriglyceridemia and Risk of Pancreatitis. New England Journal of Medicine. 2026;395(18):1805-1817. PMID 42981569. https://doi.org/10.1056/NEJMoa2610014
National Library of Medicine. Triglycerides Test. MedlinePlus. Last updated December 9, 2024. https://medlineplus.gov/lab-tests/triglycerides-test/
National Library of Medicine. Pancreatitis. MedlinePlus. Last updated September 13, 2024. https://medlineplus.gov/pancreatitis.html
Mayo Clinic. Triglycerides: Why do they matter? Mayo Clinic. Jan. 21, 2026. https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/triglycerides/art-20048186
Medical disclaimer
This article is for general education and does not replace advice from your doctor, pharmacist or another qualified healthcare professional. Never start, stop or change a lipid-lowering medicine without your doctor's guidance. If you have sudden, severe upper abdominal pain with nausea or vomiting, seek emergency care right away.
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