Phase 3 Huntington's Disease Trial, Terminated NCT05655520 Sponsor: Supernus Pharmaceuticals, Inc. Condition: Huntington's Disease
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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 enrolled 153 participants across two groups: 72 people in "Cohort 1 (Direct Rollover)" and 81 people in "Cohort 2 (Gap Rollover)." These labels suggest participants had previously been in a related study and either moved straight into this one or had a break in between. The trial's primary focus was on tracking unwanted medical events (called treatment-emergent adverse events, or TEAEs — meaning any new or worsening health issue that appeared after starting the study treatment) and on measuring changes in basic physical signs like blood pressure and heart rate. The reported data shows that in Cohort 1, 46 out of 72 participants experienced at least one such unwanted medical event, and the same number — 46 out of 81 — did so in Cohort 2. Breaking those down by how serious they felt: in Cohort 1, 21 participants had mild events, 22 had moderate events, and 3 had severe events; in Cohort 2, 24 had mild, 18 had moderate, and 4 had severe events. A small number of participants left the study because of these events — 2 in Cohort 1 and 3 in Cohort 2. For the physical measurements, the reported changes from the start of the study to the last recorded point were very small: blood pressure shifted by only a few millimetres of mercury (mmHg) in either direction depending on position and group, heart rate changed by roughly 2 beats per minute across both groups, and breathing rate was essentially unchanged (0.0 to −0.1 breaths per minute). It is worth noting that very few participants formally "completed" the study as defined by the trial — only 2 in Cohort 1 and 4 in Cohort 2 — though the data does not explain why the rest did not reach that milestone. No secondary outcome data appears to have been reported in the submitted results. These are the results as reported to ClinicalTrials.gov. They are not medical advice — always discuss what they mean for you with your doctor.

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 Huntington's Disease Trial, Terminated

NCT05655520
Terminated Phase 3 🇦🇺 Australian site

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:

  • You either completed one of two specific earlier related studies (NCT05107128 or NCT05358821), or you meet the requirements to join as a new participant.
  • You are willing to avoid recreational drugs for the whole study, and avoid alcohol for 48 hours before each visit.
  • You are willing to invite a trusted person aged 18 or older (such as a family member or friend) to participate alongside you, if you have someone available.
  • You are able to travel to the study centre regularly and are likely to be able to keep doing so for the full duration of the study.

For new participants only (not from the earlier studies), you must also:

  • Be between 25 and 65 years old at the time of screening.
  • Have a genetically confirmed Huntington's disease (HD) diagnosis with a specific gene expansion result of 40 or above, and no signs of the juvenile form of HD.
  • Have a specific disease score of 90 or above, calculated using your age and gene test result (confirm with trial site).
  • Meet one of two specific combinations of scores on standard HD assessment tests measuring daily functioning and memory/thinking ability (confirm with trial site).

Who may not be able to join:

  • You have been diagnosed with another ongoing brain or nerve condition besides HD, such as Alzheimer's disease, Parkinson's disease, vascular dementia, or dementia with Lewy bodies.
  • You have had gastric bypass surgery, currently have a gastric sleeve or lap band, or have had any procedure that affects how food moves through your digestive system.
  • You have a known allergy to any ingredient in the study drug SAGE-718, including soy lecithin.
  • You are taking or have taken certain medications not allowed in this study within the 30 days before screening, or during the study (confirm with trial site for the specific list).

For new participants only, you also may not be able to join if:

  • You have previously received gene therapy, or have taken part in another HD experimental drug or device trial within the last 180 days, or another non-HD experimental trial within the last 30 days (or longer, depending on the drug).
  • You have previously been treated with antisense oligonucleotides or a specific type of gene-modifying treatment called an mRNA splicing modifier (confirm with trial site).
  • Note: If you were confirmed to have received a placebo (dummy treatment) in a previous trial, this would not exclude you.

For participants from the two earlier studies only:

  • You have one or more serious ongoing side effects from the previous study.
  • You have ongoing unresolved side effects that the study doctor believes could interfere with how the study is carried out.

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.

This is a simplified plain English summary of the eligibility criteria. Full criteria are set by the trial investigators and may include additional requirements not shown here. Never self-exclude from a trial based on this summary. Contact the trial site directly to confirm your eligibility.
Last synced 28 July 2026
Phase 3: approximately ~65% of drugs entering this phase reach regulatory approval, based on published industry-wide historical data. This is not specific to this trial.
Phase success rates shown are historical industry-wide averages based on published data. They are not a prediction for this specific trial or your individual situation.

Contact this trial

Australian sites

Sage Investigational Site, Westmead, New South Wales
Sage Investigational Site, Caulfield South, Victoria
Sage Investigational Site, Nedlands, Western Australia

Contact details sourced from ClinicalTrials.gov. Verify directly with the trial site before attending.

GP referral letter

Print a one-page summary to share with your doctor.

Trial details

Status
Terminated
Phase
Phase 3
Sponsor
Supernus Pharmaceuticals, Inc.
Registry
ClinicalTrials.gov
Start date
14 December 2022
Est. completion
20 January 2025

Where this trial is recruiting

🇦🇺 Australia 🇨🇦 Canada 🇬🇧 United Kingdom 🇺🇸 United States

3 site(s) in Australia. Confirm current status and contact details directly with the trial site.

Primary endpoints

Number of Participants With at Least One Treatment-Emergent Adverse Events (TEAEs); Number of Participants With at Least One TEAE by Severity; Number of Participants Who Withdrew From Study Due to TEAEs; Change From Baseline in Vital Signs: Blood Pressure; Change From Baseline in Vital Signs: Heart Rate; Change From Baseline in Vital Signs: Respiratory Rate; Change From Baseline in Vital Signs: Temperature; Change From Baseline in Clinical Laboratory Parameters: Hematology - Basophils, Eosinophils, Erythrocytes, Leukocytes, Lymphocytes, Monocytes, Neutrophils, Platelets; Change From Baseline i...

Can't join this trial?

Expanded access pathways

If this trial is not available to you, other access pathways may exist. In Australia, the TGA Special Access Scheme allows access to unapproved therapeutic goods for individual patients.

TGA Special Access Scheme information

Find other recruiting trials on ClinicalTrials.gov

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.

Trial recruitment status can change without notice between our nightly data updates. Always contact the trial site directly to confirm current recruitment status before making any decisions or travel arrangements.

View original record on ClinicalTrials.gov