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 (NCT05358717) enrolled 159 people across three groups — 53 received a placebo (a dummy treatment with no active ingredient), 52 received a 5 mg dose of PTC518, and 54 received a 10 mg dose of PTC518. The trial was studying PTC518, an investigational oral tablet being tested in people with Huntington's disease. The main things being measured were how many participants experienced unexpected medical events (called adverse events) after taking the study drug, and how much a specific protein linked to Huntington's disease — called total huntingtin protein, or tHTT — changed in the blood after three months of treatment. The reported data shows that for the primary outcomes, 46 out of 53 placebo participants, 43 out of 52 in the 5 mg group, and 49 out of 54 in the 10 mg group experienced at least one adverse event during the study. Regarding the blood tHTT protein levels at three months, the placebo group showed a change of approximately −1.4%, while the 5 mg group showed approximately −17.4% and the 10 mg group approximately −28.7% — meaning the protein level appeared lower in the PTC518 groups compared to placebo. By 12 months, the reported protein changes were approximately +8.2% for placebo, −14.2% for the 5 mg group, and −28.4% for the 10 mg group. A similar protein measured in spinal fluid (mutant huntingtin) also showed reported changes at 12 months: approximately −15.6% for placebo, −23.7% for the 5 mg group, and −23.3% for the 10 mg group. For a brain structure called the caudate (which can shrink in Huntington's disease), the reported volume changes at 12 months were approximately +4.4% for placebo, +5.0% for the 5 mg group, and +5.7% for the 10 mg group. A combined score measuring movement, thinking, and daily functioning (called the cUHDRS, where a higher score means better functioning) changed by approximately −0.64 points in the placebo group, −0.61 in the 5 mg group, and −0.92 in the 10 mg group at 12 months. 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 38489195) ↗
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 2 Rare Disease Trial, Completed
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 have been diagnosed with Huntington's Disease (HD) confirmed by a genetic test, with a specific genetic marker (CAG repeat) measured between 40 and 50
- For one group (earlier stage HD): Your doctor has assessed that you are currently fully independent in daily life and have a high level of functional ability, based on standard HD rating scales, and your disease progression score falls within a specific range (confirm with trial site)
- For another group (mild early-stage HD): Your doctor has assessed that you have a slightly reduced level of functional ability based on standard HD rating scales (confirm with trial site)
Who may not be able to join:
- You have taken part in another experimental drug study within the last 90 days, or have ever received experimental treatments that target genetic material (such as antisense oligonucleotides) specifically for HD, or have had experimental brain surgery or cell transplantation
- You have ever received gene therapy for Huntington's Disease
- You have taken part in any other investigational study or program (including exercise, cognitive therapy, or brain stimulation studies) within the last 90 days
- You have a history of brain or spinal conditions that could make a lumbar puncture (spinal tap) unsafe
- You have a medical condition or history that would prevent you from completing all required study tests, for example having a shunt in your brain or being unable to have an MRI scan
- You are currently pregnant, breastfeeding, or planning to become pregnant during the study or within 6 months of finishing treatment
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.
Contact this trial
Australian sites
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
Where this trial is recruiting
2 site(s) in Australia. Confirm current status and contact details directly with the trial site.
Primary endpoints
Number of Participants With Treatment-emergent Adverse Events (TEAEs); Percent Change From Baseline in Geometric Mean Blood tHTT Protein at Month 3
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.