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Switch to once‑daily eliglustat maintains stability in adult Gaucher disease type 1 patients who are CYP2D6 intermediate or extensive metabolizers

Verified siteRegistered drugNo placebo
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What is this trial about?

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

Gaucher disease type 1 is a rare inherited disorder in which a missing enzyme causes fatty substances to build up in the spleen, liver, bones and blood. This buildup can lead to anemia, low platelet counts, an enlarged spleen, and bone problems. The medication being studied is eliglustat, an oral capsule taken by mouth that lowers the production of the fatty substances that accumulate in the body.

The study aims to find out whether changing the dosing schedule from twice a day to once a day keeps patients clinically stable for at least one year. Participants are adults who have a normal or partly reduced activity of the protein CYP2D6, which helps the body process medicines, and who have already been stable on the twice‑daily regimen.

During the trial, patients will switch to a single daily dose of the medication and will be monitored for 12 months. Regular check‑ups will include blood tests to measure hemoglobin (the protein that carries oxygen), platelet count (cells that help blood clot), and two disease‑specific markers called Chito and Lyso‑GL1 that reflect the amount of fatty material in the body. Optional extra blood samples may be taken to see how the drug level in the blood relates to stability of these markers.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline Assessment

    After joining the study, you will attend a baseline visit where your health status is recorded. This includes a physical exam, blood tests to measure hemoglobin, platelet count, chitotriosidase (referred to as Chito), and Lyso‑GL1, and confirmation that you are a CYP2D6 intermediate or extensive metabolizer. Your current treatment with eliglustat taken twice daily will also be reviewed.

  2. Step 2

    Switch to Once‑Daily Dosing

    Starting the day after the baseline visit, you will change from taking two 84 mg hard capsules of eliglustat each day (BID, meaning twice daily) to taking one 84 mg capsule once each day (QD, meaning once daily). The capsule is taken by mouth as directed, and you will be instructed to keep the same timing each day.

  3. Step 3

    Quarterly Follow‑Up Visits

    You will return to the clinic at Month 3, Month 6, Month 9, and Month 12. At each visit, a health professional will repeat the blood tests for hemoglobin, platelets, Chito, and Lyso‑GL1 to check that the disease remains stable. The doctor will also ask about any new symptoms or side effects.

    During these visits, optional blood samples may be taken to measure the level of eliglustat in your plasma. This optional test helps explore the relationship between drug concentration and disease stability (pharmacokinetic‑pharmacodynamic relationship).

  4. Step 4

    Final Assessment and Study Completion

    At the Month 12 visit, the final set of measurements will be performed. The study will determine whether you have remained clinically stable, meaning no predefined criteria for disease progression have been met. Your overall experience with the once‑daily regimen will be recorded, and you will be thanked for completing the study.

Who can join the trial?

4 criteria

  • You must be an adult (18 years or older) who has a confirmed diagnosis of Gaucher disease type 1 and needs treatment, as decided by a team of specialist doctors.
  • Your body must have a CYP2D6 intermediate or extensive metabolizer status. This means the protein called CYP2D6, which helps break down medicines, works at a normal or faster speed in your body.
  • You must have taken the medicine eliglustat 84 mg twice a day (BID) for at least six months. “BID” simply means two doses each day.
  • Your disease must be stable, which means all of the following are true:
    Hemoglobin level ≥ 9.7 g/dL (hemoglobin carries oxygen in your blood)
    Platelets count ≥ 100 × 10⁹/L (platelets help your blood clot)
    If you still have a spleen, its size is less than 10 multiples of normal (MN); if the spleen is removed, this does not apply
    Liver size is less than 1.5 MN
    No bone crisis (sudden severe bone pain) or other noticeable bone disease in the past 12 months

Who cannot join the trial?

6 criteria

  • You must not have a CYP2D6 poor metabolizer status, which means your body processes certain medicines very slowly.
  • You cannot have an active malignancy (a current cancer) or any serious, uncontrolled health problem that could affect the study results or increase your risk.
  • Pregnancy or breastfeeding (lactation) disqualifies you from the study.
  • Using strong medicines that block or increase the activity of the enzymes CYP2D6 or CYP3A (proteins that help your body break down drugs) is not allowed, as listed in the drug’s official information.
  • If you have missed doses of your current medication or cannot follow the study’s required visits and procedures, you cannot take part.
  • Being in another research study that tests a treatment (an interventional trial) within the past three months prevents participation.
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Investigated drugs

Cerdelga is an oral capsule taken by mouth that contains the medicine eliglustat. In this study, patients with Gaucher disease type 1 who can process the drug normally (CYP2D6 intermediate or extensive metabolizers) switched from taking the capsule twice a day to taking it once a day. The purpose of the medication is to help keep the disease stable by reducing the buildup of fatty substances that can damage organs. The trial is checking whether the once‑daily schedule can maintain the same level of disease control over a year as the twice‑daily schedule.

What is already known about the treatment

Cerdelga 84 mg hard capsules - It is taken by mouth as a hard capsule, 84 mg once daily. Eliglustat is an approved orphan drug for Gaucher disease type 1 and is described in many clinical studies. It works by blocking an enzyme that makes a fatty substance that builds up in patients, reducing the storage material in cells. It belongs to the class of substrate reduction therapies, which lower the amount of material that the missing enzyme would normally break down.

Investigated diseases

Gaucher disease type 1 - Gaucher disease type 1 is a hereditary disorder in which a missing enzyme causes fatty substances to build up in certain cells, especially in the spleen, liver, and bone marrow. Over time, the accumulation can lead to an enlarged spleen or liver, lower blood counts, and bone pain or fractures. The disease usually progresses slowly, and many people experience gradual changes in organ size and blood values as they age. Symptoms may vary from mild to more noticeable, but the condition does not involve the brain or nervous system.
Trial detailsLast updated 25 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2026-527117-33-00Protocol codeONCEEstimated enrolment7 patientsSponsorAmsterdam UMC Stichting

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