Study of MAR001 in Adults With Elevated Triglycerides and Remnant Cholesterol

Inclusion Criteria: * Elevated fasting TGs and RC * Elevated nonfasting TGs and RC * Part A only: Fasting LDL-C ≥ 50 mg/dL (≥ 1.29 mmol/L) and ≤ 130 mg/dL (≤ 3.36 mmol/L) * Willingness to provide informed consent and comply with the intervention and all study assessments * Stable diet for a minimum of 3 months prior to screening and with no plans to change during screening or trial participation * Stable drug regimen (if relevant) prior to screening visit and no planned changes after enrollment; Part B only: adjustment of lipid-lowering therapy during the diet/lifestyle run-in period is permitted Exclusion Criteria: * Acute or chronic liver disease * Part A only: TG concentration ≥880mg/dl; Part B only: TG concentration ≥2000 mg/dL * History of type 1 diabetes mellitus or history of diabetic ketoacidosis * Newly diagnosed T2DM * Participants with known active hepatitis A, B, or C * Uncontrolled hypothyroidism * Part B only: recent history of active pancreatitis * Part B only: genetically confirmed Familial Chylomicronemia Syndrome (FCS) diagnosis due to biallelic loss of function mutations in LPL or GPIHBP1 * Part B only: use of ANGPTL3 and ApoC-III inhibitors * Any condition that prevents the participant from complying with study procedures