The purpose of this study is to determine if implitapide, used in conjunction with other lipid-lowering therapies, is safe and effective when compared to placebo in lowering low-density lipoprotein cholesterol (LDL-C) in patients with heterozygous familial hypercholesterolemia (HeFH).
Inclusion Criteria: In order to participate in this study, patients must meet all of the following inclusion criteria: * be between 18 and 70 years old with a diagnosis of HeFH; * be stable on and maintain concomitant therapy with hypolipidemic drugs or treatments; * have an appropriate calculated, fasting LDL-C levels and an appropriate triglyceride (TG) level; * be male or nonpregnant, nonlactating female; * give informed consent; and * meet body weight requirements. Exclusion Criteria: In order to participate in this study, patients must not meet any of the following exclusion criteria: * recent myocardial infarction, percutaneous transluminal coronary intervention, coronary artery bypass graft surgery, or cerebrovascular accident; * uncontrolled hypothyroidism or other uncontrolled endocrine disease; * known, clinically significant eye abnormalities (e.g., cataracts); * appropriate serum creatinine phosphokinase levels; * history of liver disease or liver enzyme levels above appropriate levels; * alkaline phosphatase above appropriate levels; * serum creatinine above appropriate levels; * liver cirrhosis and severe liver steatosis; * clinically significant infection, malignancy, or psychosis; * use of oral anticoagulants or digoxin, unless the dose has been stable for 4 weeks; * participation in any other investigational study, including device or observational studies, within 30 days; * lactating or have a positive serum pregnancy test; * current drug or alcohol abuse; or * unwillingness to comply with study procedures, including follow-up, as specified by this protocol, or unwillingness to cooperate fully with the investigator