Baseline was defined as the last value prior to receiving the first dose of mipomersen in this study (for participants randomized to placebo in their index study and for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \>=6 months from their last dose of mipomersen in their index study), or the last value prior to receiving the first dose of mipomersen in their index study (for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \<6 months from their last dose of mipomersen in their index study).

Baseline was defined as the last value prior to receiving the first dose of mipomersen in this study (for participants randomized to placebo in their index study and for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \>=6 months from their last dose of mipomersen in their index study), or the last value prior to receiving the first dose of mipomersen in their index study (for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \<6 months from their last dose of mipomersen in their index study).

Baseline was defined as the last value prior to receiving the first dose of mipomersen in this study (for participants randomized to placebo in their index study and for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \>=6 months from their last dose of mipomersen in their index study), or the last value prior to receiving the first dose of mipomersen in their index study (for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \<6 months from their last dose of mipomersen in their index study).

Baseline was defined as the last value prior to receiving the first dose of mipomersen in this study (for participants randomized to placebo in their index study and for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \>=6 months from their last dose of mipomersen in their index study), or the last value prior to receiving the first dose of mipomersen in their index study (for participants randomized to mipomersen in their index study and their first dose of mipomersen in this study was administered \<6 months from their last dose of mipomersen in their index study).

LDL-C was measured in mg/dL. Samples were taken following an overnight fast. For patients with triglycerides \<400 mg/dL, LDL-C was obtained using Friedewald's calculation; and for patients with triglycerides \>=400 mg/dL, LDL-C was directly measured by the central laboratory using ultracentrifugation. Baseline was defined as the average of the screening and Study Day 1 (pre-treatment) assessments. An assessment was not included in this calculation if it was associated with a non-fasting blood draw or was drawn more than 4 weeks prior to Study Day 1. If the Study Day 1 and screening LDL-C values were \>12% different (relative to the maximum value), then the screening value was not used, because the Study Day 1 value represents the best estimate of the patient's condition at the beginning of study drug administration. The PET was the post-baseline visit, for which LDL-C was assessed, closest to 14 days after the last dose of study drug.

The PET was the post-baseline visit, for which LDL-C was assessed, closest to 14 days after the last dose of study drug.

LDL cholesterol was measured in mg/dL. Samples were taken following an overnight fast. For patients with triglycerides \<400 mg/dL, LDL-C was obtained using Friedewald's calculation; and for patients with triglycerides ≥400 mg/dL, LDL-C was directly measured by the central laboratory using ultracentrifugation. For patients who were on placebo in the index study or who took their last dose of mipomersen ≥6 months prior to first dose in this study, Baseline is defined as the last measurement prior to first dose in this study. For participants who took their last dose of mipomersen less than 6 months before starting this study, Baseline is defined as the last measurement taken prior to receiving a first dose in the index study.

Samples were taken following an overnight fast. For patients with triglycerides \<400 mg/dL, LDL-C was obtained using Friedewald's calculation; and for patients with triglycerides ≥400 mg/dL, LDL-C was directly measured by the central laboratory using ultracentrifugation. For patients who were on placebo in the index study or who took their last dose of mipomersen ≥6 months prior to first dose in this study, Baseline is defined as the last measurement prior to first dose in this study. For participants who took their last dose of mipomersen less than 6 months before starting this study, Baseline is defined as the last measurement taken prior to receiving a first dose in the index study.

Localized proton MRS was used to quantify liver TG concentration. All MRS imaging of the liver was performed using the same 1.5T scanner. The instructions were to cover the entire liver (from just above the dome to just below the inferior tip) using a qualified imaging technique (Yokoo, 2009, Radiology). Liver fat quantification was performed by determining the liver fat fraction (%) derived from MRS using selected Regions of Interest (ROI). The analyst typically looked for the branching of the right portal vein and mapped slices from one scan to the next. There were typically 2 ROIs in the right lobe and 1 in the left lobe. Magnetic resonance spectroscopy imaging ROIs between different scans were selected using anatomical landmarks for both time points.