A Study of Olezarsen (Formerly Known as AKCEA-APOCIII-LRx) in Participants With Familial Chylomicronemia Syndrome (FCS)

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the effect of olezarsen (formerly known as AKCEA-APOCIII-LRx) on the percent change in fasting triglycerides (TG) from baseline.

Detailed Description
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This is a multi-center, open-label extension (OLE) study of up to 60 participants with FCS rolling-over from Study ISIS 678354-CS3 (NCT04568434). Participants will receive olezarsen during a 157-week treatment period, followed by a 13-week post-treatment follow-up period. The length of participation in this study is approximately 201 weeks, which includes an up to 31-day qualification period, a 157-week treatment period, and a 13-week post-treatment evaluation period. Treatment has been extended to obtain additional safety assessments and efficacy data and to provide patients with continued access to ISIS 678354 until the drug may be available commercially.

Official Title
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An Open-Label Extension Study of AKCEA-APOCIII-LRx Administered Subcutaneously to Patients With Familial Chylomicronemia Syndrome (FCS)

Conditions
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Familial Chylomicronemia Syndrome

Intervention / Treatment
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* Drug: Olezarsen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • Satisfactory completion of treatment with olezarsen in the index study (ISIS 678354-CS3, last dose as scheduled at Week 49) with an acceptable safety profile, per Investigator judgement. Exclusion Criteria: • Have any new condition or worsening of existing condition which in the opinion of the Investigator would make the participant unsuitable for enrollment, or could interfere with the patient participating in or completing the study, including need for treatment with medications disallowed in the index study (ISIS 678354-CS3).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Olezarsen<br>Olezarsen will be administered once every 4 weeks by subcutaneous (SC) injection from Week 1 through Week 153. | Drug: Olezarsen<br>* Olezarsen will be administered by SC injection.<br>* Other names: AKCEA -APOCIII-LRx;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change From Baseline in Fasting TG at 6 Months (Average of Weeks 23, 25, and 27) Compared to Baseline |  | Baseline and 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change From Baseline in Fasting TG at 12 Months (Average of Weeks 51 and 53) at 24 Months (Average of Week 103 and Week 105) and 36 Months (Average of Week 155 and Week 157) |  | Baseline and 36 months | 
| Percentage of Participants Who Achieve ≥ 40% Reduction in Fasting TG From Baseline at 6 Months |  | At 6 months | 
| Percentage of Participants Who Achieve ≥ 40% Reduction in Fasting TG From Baseline at 12, 24, 36 Months |  | At 12, 24, 36 months | 
| Percent Change in Fasting apoC-III from Baseline at Month 6 |  | Baseline and 6 months | 
| Percent Change in Fasting apoC-III from Month 12, 24, 36 |  | At 12, 24, 36 months | 
| Percent Change From Baseline in Fasting Apolipoprotein 48 (apoB48) at 6 Months |  | At 6 months | 
| Percent Change From Baseline in Fasting apoB48 at 12, 24, 36 Months |  | At 12, 24, 36 months | 
| Percent Change in Fasting non-HDL-C from Baseline at Month 6 |  | Baseline and 6 months | 
| Percent Change in Fasting non-HDL-C from Months 12, 24, 36 |  | At 12, 24, 36 months | 
| Percentage of Participants Who Achieve Fasting TG ≤ 880 milligrams per deciliter (mg/dL) at 6 Months |  | At 6 months | 
| Percentage of Participants Who Achieve Fasting TG ≤ 880 mg/dL at 12, 24, 36 months |  | At 12, 24, 36 months | 
| Adjudicated Acute Pancreatitis Event Rate During the Treatment Period in Participants With ≥ 2 Events of Adjudicated Acute Pancreatitis in 5 Years Prior to Treatment With Study Drug in the Index Study |  | Week 1 through Week 157 | 
| Adjudicated Acute Pancreatitis Event Rate During the Treatment Period |  | Week 1 through Weeks 53, 105, or 157 | 
| Adjudicated Acute Pancreatitis Event Rate During the Treatment Period in Patients with a Prior History of Pancreatitis within 10 Years Prior to Screening in the Index Study |  | Week 1 through Weeks 53, 105, or 157 | 
| Percentage of Participants Who Achieve ≥ 70% Reduction in Fasting TG From Baseline at 6 Months |  | At 6 months | 
| Percentage of Participants Who Achieve ≥ 70% Reduction in Fasting TG From Baseline at 12, 24, 36 Months |  | At 12, 24, 36 months | 
| Percentage of Participants Who Achieve Fasting TG ≤ 500 mg/dL at 6 Months |  | At 6 months | 
| Percentage of Participants Who Achieve Fasting TG ≤ 500 mg/dL at 12, 24, 36 Months |  | At 12, 24, 36 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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FCS