Trial results
AI generated results summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
According to the results reported on ClinicalTrials.gov, this trial (NCT04221451) looked at a medicine called venglustat in people with certain rare inherited conditions affecting the nervous system. The main group studied had a condition called Niemann-Pick disease type C (referred to as the "primary population"), while a smaller "secondary population" included people with related conditions such as GM1 or GM2 gangliosidosis, sialidosis type 1, and galactosialidosis. In the first phase of the trial (up to about two years), 19 participants received a placebo (a dummy treatment with no active ingredient), 40 received venglustat, and 16 were in the secondary population group receiving venglustat. Most participants who started this phase completed it. A second, longer phase then followed for those who continued, though the reported data shows that none of those participants had fully completed that extended phase at the time results were submitted. The reported data shows that one of the key things measured in the primary population was the change in a biological marker called GM2 — a substance found in the fluid surrounding the brain and spine — which was used as a signal of disease activity. After about two years, the placebo group showed an average reduction of around 11% in this marker, while the venglustat group showed an average reduction of around 48%. The trial also measured how quickly arm and hand function changed over time using a peg-placing test; the reported data shows the placebo group's score worsened at a rate of about 0.95% per year, compared to about 2.49% per year in the venglustat group — noting that a higher number on this test indicates greater difficulty. For participants in the secondary population with GM2 gangliosidosis, the reported data shows reductions in relevant biological markers ranging from roughly 43% to 82%. For those with GM1 gangliosidosis, reductions in some markers of around 32% to 80% were reported, though one marker showed an increase of about 17%. For the sialidosis type 1 and galactosialidosis groups, the data was not reported. These are the results as reported to ClinicalTrials.gov. They are not medical advice — always discuss what they mean for you with your doctor.
View full results on ClinicalTrials.gov ↗ · Read the linked publication on PubMed (PMID 34539759) ↗
These are the results as reported to ClinicalTrials.gov, not medical advice. Verify independently with the trial site and discuss what they mean for you with your doctor.
Phase 3 Rare Disease Trial, Terminated
Who may be able to join
AI generated eligibility summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
Who might be able to join this trial:
- Adults aged 18 or older, OR children/teenagers aged 2 to under 18 who weigh at least 10 kg (about 22 lbs)
- Adults diagnosed with late-onset Tay-Sachs disease or Sandhoff disease caused by specific gene mutations (HEXA or HEXB genes)
- Children/teenagers or adults diagnosed with certain related conditions, including juvenile GM2 gangliosidosis, GM1 gangliosidosis, saposin C deficiency, sialidosis type 1, or juvenile adult galactosialidosis
- Adults in the main group must be able to complete a hand and finger coordination test (picking up and placing small pegs) within 240 seconds at the initial screening visit
- People who have a history of seizures that are well controlled by certain medications (not all seizure medications qualify — confirm with trial site)
- People who are able to swallow oral medication, are willing to travel to the study site if needed, and can follow all study requirements as judged by the study doctor
- People who are willing and able to sign a consent form agreeing to participate
- Sexually active participants must use contraception; women must not be pregnant or breastfeeding; men must not donate sperm during the study
Who may not be able to join:
- People who have symptoms similar to Tay-Sachs or Sandhoff disease but whose condition is NOT caused by mutations in the HEXA or HEXB genes, or who have no symptoms at all
- People (in certain groups) who are unable to understand and complete the age-appropriate tests and assessments required by the study
- People with serious other medical conditions that could put their safety at risk
- People who have been diagnosed with Hepatitis B, Hepatitis C, or HIV
- People with certain types of cataracts (clouding of the eye lens) at a moderate or severe level — though a specific type called nuclear cataracts is allowed (confirm with trial site)
- People who need a breathing machine (invasive ventilator) to breathe
- People currently taking blood thinners, medications known to cause cataracts, or medications that could worsen vision in people with cataracts
- People who have taken a type of treatment called substrate reduction therapy in the past 3 months, or certain other specific medications within a set time before the study starts
- People who have eaten grapefruit or drunk grapefruit juice within 72 hours before starting the study medication
- People who are currently taking part in another clinical study
- People who have taken an experimental medication within 3 months (or longer, depending on the drug) before joining this study
- People with significantly elevated liver enzyme levels or bilirubin levels in their blood at the time of screening, unless they have a specific harmless condition called Gilbert syndrome with levels within defined limits (confirm with trial site)
- People with significantly reduced kidney function, as measured by a specific blood test at the screening visit (confirm with trial site)
Important: Always verify eligibility with the trial site directly before applying.
Based on publicly available eligibility criteria from ClinicalTrials.gov. Verify directly with the trial site before acting. This is not medical advice.
GP referral letter
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Trial details
Where this trial is recruiting
Primary endpoints
PAP: PP: Percent Change From Baseline in CSF GM2 Biomarker to Week 104; PAP: PP: Annualized Rate of Change From Baseline in the 9-HPT to Week 104; PAP: SP: Percent Change From Baseline in Plasma and CSF Biomarkers (Glucosylceramide [GL-1] and GM2) to Week 104 in Juvenile/Adolescent Late-onset GM2 Gangliosidosis Participants; PAP: SP: Percent Change From Baseline in Plasma and CSF GL-1 and GM1 Biomarkers to Week 104 in GM1 Gangliosidosis Participants; PAP: SP: Percent Change From Baseline in Plasma and CSF GL-1, GM2 and Monosialodihexosylganglioside (GM3) Biomarkers to Week 104 in Sialidosis Ty...
Can't join this trial?
Data last synced from ClinicalTrials.gov: 28 July 2026. Trial status can change. Always verify current status directly with the trial site before making any decision.