Phase 2 Study of AKCEA-ANGPTL3-LRx (ISIS 703802) in Participants With Familial Chylomicronemia Syndrome (FCS)

Key Inclusion Criteria: * Genetically confirmed chylomicronemia syndrome. * Fasting triglycerides greater than or equal to (\>=) 750 milligrams per deciliter (mg/dL) \[8.4 millimoles per liter (mmol/L)\] at Screening. Key Exclusion Criteria: * Diabetes mellitus if newly diagnosed or if glycated hemoglobin (HbA1c) \>= 9.0%. * Active pancreatitis within 2 weeks of screening. * Acute coronary syndrome within 6 months of screening. * Major surgery within 3 months of screening. * Treatment with Glybera therapy within 2 years of screening. * Previous treatment with AKCEA-ANGPTL3-LRx. * Have any other conditions in the opinion of the investigator which could interfere with the patient participating in or completing the study.