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A Study of Enlicitide for Safety and Effectiveness in Children and Adolescents with Heterozygous Familial Hypercholesterolemia

Fast replyInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study is looking at heterozygous familial hypercholesterolemia in children, which is an inherited condition that causes high cholesterol levels from a young age. The study will test a medication called enlicitide, which has the code name MK-0616, given as a film-coated tablet that is taken by mouth. Some participants will receive placebo instead of the actual medication for comparison. The purpose of this study is to see how well enlicitide works in lowering cholesterol levels in children with this condition, to understand how the medication moves through the body in different age groups, and to check its safety when used in pediatric patients.

The study is divided into different parts. Part A will look at how the medication is processed in the body in two age groups: children aged 12 to under 18 years and children aged 6 to under 12 years. Part B will compare the effects of enlicitide to placebo over 24 weeks, measuring changes in low-density lipoprotein cholesterol, which is a type of harmful cholesterol often called bad cholesterol. The study will also measure other cholesterol-related substances in the blood, including apolipoprotein B, non-high-density lipoprotein cholesterol, and lipoprotein (a). Additionally, the study will use ultrasound to check for changes in the thickness of blood vessel walls. Children participating in the study will continue taking their current cholesterol-lowering medications at stable doses throughout the study.

After completing either Part A or Part B, participants may have the option to continue in an open-label extension period, where they will receive the active medication. Throughout all parts of the study, doctors will closely monitor participants for any side effects or unwanted reactions to the treatment. The study will track how many participants experience any health problems and whether any participants need to stop taking the medication because of side effects. The maximum daily dose of enlicitide used in this study will be 20 milligrams, and participants may receive treatment for up to 180 weeks depending on which part of the study they join.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial treatment period assignment

    Upon joining the study, you will be assigned to one of two parts based on your age. Age Cohort 1 includes participants aged 12 to less than 18 years. Age Cohort 2 includes participants aged 6 to less than 12 years.

    You will first enter either Part A or Part B of the study. Part A focuses on measuring how the medication moves through your body. Part B compares the effectiveness of the medication against a placebo, which is an inactive substance that looks like the medication but contains no active ingredient.

  2. Step 2

    Part A: medication intake and monitoring

    If you are assigned to Part A, you will receive enlicitide, also known as MK-0616. This medication is provided as a film-coated tablet that you will take by mouth.

    The study will measure the maximum concentration of the medication in your blood and the total amount of medication in your blood over 24 hours.

    Part A lasts until Day 14, at which point you will have completed Visit 5. After completing this visit, you may be eligible to continue into the open-label extension period.

  3. Step 3

    Part B: randomized treatment period

    If you are assigned to Part B, you will be randomly assigned to receive either enlicitide (MK-0616) or a placebo. The placebo looks identical to the active medication but contains no active ingredient.

    The medication or placebo is provided as a film-coated tablet that you will take by mouth.

    Throughout Part B, you will continue taking your current cholesterol-lowering medications at the same doses you were taking before joining the study. These may include statins or other medications used to lower cholesterol levels.

    Part B lasts for 24 weeks. During this time, the study will measure changes in your LDL cholesterol, which is often called bad cholesterol, and other cholesterol-related markers in your blood.

  4. Step 4

    Monitoring during Part B

    Throughout the 24-week period of Part B, regular visits will occur to monitor your health and measure various cholesterol levels in your blood.

    The study will track changes in LDL cholesterol, apolipoprotein B (a protein that carries cholesterol in your blood), non-HDL cholesterol (all cholesterol except the good kind), and lipoprotein (a), which is another type of cholesterol particle.

    An ultrasound measurement of the thickness of the inner layers of your carotid artery (a major blood vessel in your neck) may also be performed to assess changes over time.

    At Week 24, you will complete Visit 7, marking the end of Part B.

  5. Step 5

    Open-label extension period

    After completing Part A (at Day 14) or Part B (at Week 24), you may be eligible to enter the open-label extension period. During this phase, all participants will know they are receiving the active medication enlicitide.

    To be eligible for this extension, you must have received at least one dose of the study medication during Part A or Part B and completed the required final visit for that part.

    The open-label extension allows continued treatment and monitoring of the medication's safety and effects over a longer period of time.

    The specific duration and dosing schedule for the open-label extension period will be determined based on the study protocol.

  6. Step 6

    Safety monitoring throughout the study

    Throughout all parts of the study, including Part A, Part B, and the open-label extension, your safety will be monitored continuously.

    Any adverse events, which are unwanted or harmful effects that occur during the study, will be recorded and evaluated.

    If you experience side effects that are concerning, the study team may decide to stop your treatment with the study medication.

Who can join the trial?

6 criteria

  • The patient must have a diagnosis of heterozygous familial hypercholesterolemia, which is an inherited condition that causes high levels of cholesterol in the blood. This diagnosis should be confirmed either by a locally accepted method or by genetic testing, which is a test that looks at genes to find inherited conditions.
  • The patient must be receiving the best possible treatment according to local guidelines and their doctor's judgment. This treatment should include a daily statin, which is a type of medicine that lowers cholesterol, either alone or combined with other cholesterol-lowering medicines. If the patient cannot take statins because they have had bad reactions to at least two different statins, or if the patient or their parent refuses statin treatment, they must be taking other cholesterol-lowering medicines instead, and this must be documented in writing.
  • The patient must be taking a stable dose of all their cholesterol-lowering medicines before starting the study and throughout the study period, with no planned changes to their medicines or doses.
  • The patient must be between 12 and 17 years old for one group, or between 6 and 11 years old for another group.
  • The patient must be able to take the study medicine by mouth and must be able to swallow it.
  • For patients joining the extended part of the study, they must have already participated in an earlier part of the study, received at least one dose of the study medicine, and completed specific required visits.

Who cannot join the trial?

7 criteria

  • The study information provided does not contain specific exclusion criteria details
  • Exclusion criteria are the reasons why some patients cannot join this clinical trial
  • These criteria help ensure the safety of participants and the accuracy of study results
  • Without the detailed exclusion criteria from the study documents, we cannot list the specific reasons why a patient might not be able to participate
  • If you are interested in this study for Heterozygous Familial Hypercholesterolemia, which is a genetic condition that causes high levels of LDL-C (bad cholesterol) in the blood, the study team will review all requirements during the screening process
  • The study involves testing a medication called enlicitide in children and teenagers
  • The study doctors will check if you meet all the requirements needed to participate safely
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Investigated drugs

Enlicitide decanoate is a medication being tested to lower cholesterol levels in children and teenagers with a genetic condition that causes high cholesterol, called heterozygous familial hypercholesterolemia. This medicine is given to help reduce the amount of LDL cholesterol (often called "bad cholesterol") in the blood. The study will look at how well this medication works and how safe it is when given to young patients.

A placebo is used in this study as a comparison. A placebo looks like the real medication but does not contain any active medicine. It helps researchers understand if the actual medication is working better than no treatment at all.

What is already known about the treatment

Enlicitide Decanoate – This medication is given as an injection and is currently being studied in clinical trials for treating children and teenagers with heterozygous familial hypercholesterolemia, a genetic condition that causes high cholesterol levels from birth. The drug works by targeting specific molecules in the body to help lower LDL cholesterol, which is often called "bad cholesterol" because high levels can lead to heart disease. Enlicitide decanoate belongs to a class of cholesterol-lowering medications and is being tested to see if it is safe, effective, and well-tolerated in young patients who need help managing their cholesterol levels.

Investigated diseases

Heterozygous Familial Hypercholesterolemia – Heterozygous Familial Hypercholesterolemia is a genetic disorder that affects the way the body processes cholesterol. People with this condition inherit one altered gene from one parent, which causes high levels of low-density lipoprotein cholesterol (LDL-C) in the blood from birth. The elevated cholesterol accumulates in the blood vessels over time, leading to narrowing and hardening of the arteries. This condition can affect children and adults, causing cholesterol deposits to form in various parts of the body. Without proper management, the buildup of cholesterol in the arteries progresses throughout a person's life. The disorder is passed down through families in an autosomal dominant pattern, meaning each child of an affected parent has a 50% chance of inheriting the condition.
Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase IVTrial ID2024-519068-42-00Protocol codeMK-0616-029Estimated enrolment185 patientsSponsorMerck Sharp & Dohme LLC

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