The hypotheses to be tested and the specific aims are:~Hypothesis 1: As compared to placebo, Orlistat will be effective and safe in lowering fasting serum TG concentrations in patients with T1HLP.~Specific Aim 1: To investigate the efficacy and safety of Orlistat for reducing fasting serum TG levels in 28 patients with T1HLP in a double-blind, randomized, placebo-controlled, parallel design study for a period of 24 weeks.~Hypothesis 2: The efficacy and safety of Orlistat in patients with T1HLP will be maintained over a period of up to 48 weeks.~Specific Aim 2: To investigate the efficacy and safety of Orlistat in patients with T1HLP in an open-label extension study for a period of up to 48 weeks-.~After a screening evaluation, the subjects will be advised to consume an extremely low fat diet (≤15% of total energy from fat) for the entire duration of the study. After the baseline period of 8 weeks, they will be randomly assigned to placebo or Orlistat for the duration of 24 weeks (Phase 1). After Phase 1, all patients will enter an open-label extension (Phase 2) and receive Orlistat for a period of 24 weeks for a total study duration of 56 weeks. During the last week of Baseline Period, Phase 1, and Phase 2, blood lipids and chemistry panel will be analyzed for three consecutive days, and fat-soluble vitamin levels will be measured once. All the visits are going to be outpatient.
Type I hyperlipoproteinemia (T1HLP, also known as familial chylomicronemia syndrome or FCS) is a rare diseasewhere the blood triglycerides (fats) are very high. It is caused by lack of certain enzymes and proteins in the bodythat are important in disposing circulating fats from blood. Treatment of T1HLP patients who have very high levels of blood fats (≥ 1,000 mg/dL) is challenging as conventional triglyceride-lowering medications, such as fibrates and fishoil, are ineffective.~The purpose of this trial is to study the long-term efficacy and safety of orlistat for reducing blood triglyceride levels in patients with T1HLP.