CORE-OLE: A Study of Olezarsen (ISIS 678354) Administered Subcutaneously to Participants With Severe Hypertriglyceridemia (SHTG)

Key Inclusion Criteria:

• Satisfactory completion of either ISIS 678354-CS5 or ISIS 678354-CS6 with anacceptable safety profile, per Investigator judgment. Satisfactory completionrequires that the patient did not terminate early from treatment.

• Participants must be on a stable regimen of lipid-lowering therapy that shouldadhere to standard of care (SOC) per local guidelines. A patient may be eligible iftheir regimen of lipid-lowering therapy has been changed recently, provided thatlipid lowering medications are optimized and stabilized for at least 4 weeks priorto the end of the Qualification Period of this OLE study; ideally, such changes areinitiated after Week 53 of the index study (ISIS 678354-CS5 or CS6).

• A patient may re-enroll in the study after having completed the study when theTreatment Period was 53 weeks, if the patient satisfactorily completed the studywith an acceptable safety profile, per Investigator judgment. In the case ofre-enrollment, there is no limit on the time gap between completion of treatmentunder the previous protocol and dosing upon re-enrollment (i.e., may exceed 17 weeksbetween doses).

Key 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 participant participating in or completing the study, including need for treatment with disallowed medications, or need to change the required stable regimen as per either ISIS 678354-CS5 or ISIS 678354-CS6 study entry criteria. It is acceptable to adjust a regimen of lipid-lowering therapy as described in the second Key Inclusion Criterion above, and it is acceptable to adjust or stop lipid-lowering therapy at or after Week 13 per Investigator judgment.

NOTE: Other Inclusion/Exclusion criteria may apply.