Plozasiran (Redemplo) for Familial Chylomicronemia Syndrome
Administer plozasiran 25 mg subcutaneously every 3 months as an adjunct to a very-low-fat diet (≤20 grams fat per day) in adults with genetically confirmed FCS. 1
Dosing Regimen
Standard dose: 25 mg subcutaneous injection once every 3 months (quarterly dosing) 1
- Inject into the front of the thigh or abdomen
- The outer upper arm may be used only if administered by a healthcare provider or caregiver
- Avoid areas with damaged skin, bruising, scars, or stretch marks
- If a dose is missed: Administer as soon as possible, then resume the every-3-month schedule from the date of the most recently administered dose 1
The 25 mg dose is approved for all adult FCS patients regardless of BMI, ethnicity, or presence of mild-to-moderate renal impairment or mild hepatic impairment 2. The 50 mg dose studied in trials is not an approved regimen 1.
Dietary Requirements
Maintain strict adherence to a very-low-fat diet of ≤20 grams of fat per day throughout treatment 1. This dietary restriction is critical and non-negotiable—lipid-regulating agents do not reduce the importance of dietary fat restriction 1.
The most recent AACE 2025 guidelines emphasize that for patients with FCS or refractory multifactorial chylomicronemia syndrome (MCS), diets with <15 to 20 grams of fat per day are necessary when chylomicronemia persists 3. If maintaining adequate calorie intake becomes difficult with this severe fat restriction, medium-chain triglycerides (MCT) and essential fatty acid supplements can be added to prevent nutritional deficiencies 3.
Monitoring Schedule
Baseline Assessment
- Fasting triglyceride levels
- Apolipoprotein C-III levels
- HbA1c and fasting glucose (particularly important in patients with diabetes or prediabetes)
- Liver function tests
- Complete blood count with platelets
Ongoing Monitoring
Glycemic parameters (critical):
- Monitor HbA1c and glucose levels regularly throughout treatment
- Mean increases in HbA1c up to 0.5% were observed in clinical trials 1
- Hyperglycemia occurred in 20% of plozasiran-treated patients versus 8% with placebo 1
- This is particularly important in patients with pre-existing diabetes or prediabetes 4, 5
Lipid parameters:
- Assess fasting triglycerides at 10 months and 12 months to evaluate response
- In the PALISADE trial, median triglyceride reduction was 80% at 10 months with the 25 mg dose 4
- Monitor apolipoprotein C-III levels as a mechanistic marker
Liver function:
- Periodic monitoring of liver enzymes is warranted 6
Other parameters:
- Monitor for injection site reactions
- Unlike olezarsen (another apoC-III inhibitor), plozasiran does not require routine platelet monitoring based on current evidence 6, 7
Side Effect Management
Most Common Adverse Reactions (≥10% and >5% more than placebo):
Hyperglycemia (20% vs 8% placebo) 1
- Management approach: Intensify glycemic monitoring in patients with diabetes or prediabetes
- Adjust diabetes medications as needed
- Consider endocrinology consultation for difficult-to-control hyperglycemia
- This was the only adverse reaction leading to treatment discontinuation in trials 1
Headache (16% vs 8% placebo) 1
- Typically mild and self-limited
- Manage with standard analgesics as needed
Nausea (14% vs 8% placebo) 1
- Usually transient
- Consider antiemetics if persistent
- Ensure adequate hydration
Injection site reactions (10% vs 4% placebo) 1
- Manifestations: pain, redness, or swelling at injection site
- Rotate injection sites with each dose
- Apply ice before injection if needed
- Use proper injection technique
Serious Considerations
Pancreatitis risk reduction: The primary goal of treatment is preventing acute pancreatitis. In the PALISADE trial, plozasiran reduced the incidence of acute pancreatitis compared to placebo (odds ratio 0.17; 95% CI 0.03-0.94; P=0.03) 4. However, patients must understand that dietary fat restriction remains absolutely essential—medication alone is insufficient 1.
Discontinuation rate: Only 6% of plozasiran-treated patients discontinued due to adverse events (hyperglycemia and urticaria) versus 0% with placebo 1. Severe and serious adverse events were actually less common with plozasiran than placebo 4.
Clinical Context and Efficacy
Plozasiran works by degrading hepatic APOC3 mRNA via RNA interference, reducing apolipoprotein C-III production and thereby enhancing triglyceride clearance 8, 5. The estimated IC50 dose is only 2.2 mg, demonstrating potent pharmacological activity 2. The liver elimination half-life of 48 days supports the quarterly dosing schedule 2.
Expected outcomes:
- Median 80% reduction in fasting triglycerides at 10 months 4
- Baseline median triglyceride level in PALISADE was 2044 mg/dL, reduced to approximately 400 mg/dL 4
- Concomitant reductions in non-HDL cholesterol and apolipoprotein B 9
Important distinction: The trial included both genetically confirmed FCS patients and those with clinically diagnosed persistent chylomicronemia. There was no evidence of differential efficacy between these groups, so plozasiran is suitable for both genetic and clinical diagnoses of FCS 2.
Storage and Handling
- Store prefilled syringes refrigerated at 2°C to 8°C (36°F to 46°F) in original carton 1
- May be kept at room temperature 20°C to 25°C (68°F to 77°F) for up to 30 days
- Discard if kept at room temperature longer than 30 days 1
- Inspect solution before use—should be clear and colorless to yellow
- Do not use if cloudy, discolored, or contains particulate matter 1
Critical Pitfalls to Avoid
- Do not relax dietary fat restriction thinking medication alone is sufficient—the very-low-fat diet (≤20 g/day) is mandatory 1
- Do not overlook glycemic monitoring in patients with diabetes or prediabetes—hyperglycemia is the most significant adverse effect requiring management 1, 4
- Do not use the 50 mg dose—only 25 mg every 3 months is approved 1
- Do not assume cardiovascular benefit—while plozasiran reduces triglycerides and apoB, long-term cardiovascular outcome data are pending 9
- Do not forget professional dietetic support—maintaining <20 g fat/day is extremely challenging and requires expert guidance 3