Study to Evaluate the Efficacy and Safety of Venglustat in Adult and Pediatric Patients With Gaucher Disease Type 3

To be considered for this study, you need to be at least 12 years old and have a confirmed diagnosis of Gaucher disease type 3. You must have been receiving regular enzyme replacement therapy (like Cerezyme) for at least three years, and your treatment dose should have been steady for the last six months. Importantly, your doctor needs to agree that your overall health is stable and that your Gaucher disease is currently well-managed, with specific levels for your blood counts and organ sizes.

Also, your Gaucher disease type 3 needs to be affecting your brain in a specific way, shown by a certain score from a test called SARA, and you should have problems with your eye movements. If you've had seizures, they must be well-controlled with medication that won't interfere with the study drug. You also need to weigh at least 30 kg.

However, you won't be able to join if you need regular blood transfusions, have certain liver problems, or have other serious health conditions like heart disease that aren't related to your Gaucher disease. If you are pregnant, breastfeeding, or planning to become pregnant, you won't be able to take part. Male participants also shouldn't donate sperm during the study.

If you decide to take part, you'll first have a screening period that lasts up to 45 days. This is when doctors will check if you're suitable for the study. Once you're in, you'll be randomly assigned to one of two groups: one receiving the new medicine (venglustat) as a pill, and the other receiving the standard treatment (imiglucerase) as an intravenous infusion every two weeks. This main part of the study, where neither you nor your doctors will know which treatment you're getting, lasts for 52 weeks.

After this, there will be an optional 'open-label' period, where everyone will know which treatment they are receiving, and this will last for at least another 52 weeks. You will have regular visits to the clinic for check-ups, assessments, and to receive your medication or infusions. These visits will involve blood tests, physical exams, and tests to monitor your Gaucher disease and any effects on your brain. Once your treatment period ends, there will be a final follow-up phone call about a month later to check on how you're doing. The total time you could be involved in the study is at least two years.