This study is about testing a drug called **olezarsen** for people with **Severe Hypertriglyceridemia (SHTG)**, a condition where there is too much fat in the blood. The study will involve around 800 participants who have already taken part in earlier research. They will get the drug for about 3 years. There are three parts: a 31-day start period, a 157-week treatment period, and a 13-week follow-up. Participants should have finished earlier studies safely and be on a stable plan of **lipid-lowering therapy**, which means taking medicine to lower fat levels in the blood. You can join if your current therapy has been stable for at least 4 weeks before starting this new study.

• This study lasts for about 3 years.
• Participants must have successfully completed earlier related studies.
• You need to be on a stable fat-lowering treatment.