Huntington DiseasePhase 2NCT06254482
An Extension Study to Evaluate the Long-Term Safety and Efficacy of Votoplam in Participants With Huntington's Disease (HD)
A Phase 2 study testing Votoplam in people with Huntington Disease, run by Novartis Pharmaceuticals at 24 sites in 10 countries.
Trial summary
The primary goal of this study is to evaluate the long-term safety and pharmacodynamic effects of votoplam in participants with HD. Read more about this study
- Who is it for?
- Ages 25 years and older
- Conditions the study is for
- Huntington Disease
- What is being tested?
- Votoplam
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 144 participants
- Where
- 24 sitesin 10 countries
- Study dates
- 25 Aug 2023to 16 Jul 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participant who has completed the Treatment Period in Study PTC518-CNS-002-HD.
Who cannot join
- Participants who have not previously completed the Treatment Period in Study PTC518-CNS-002-HD.
- Note: Other inclusion and exclusion criteria may apply.
Trial locations and contacts
24 sites in 10 countries.
24 sites in 10 countries
Germany4 sites
Novartis Investigative Site
Berlin, 10117
Novartis Investigative Site
Bochum, 44791
Novartis Investigative Site
Münster, 48149
Novartis Investigative Site
Ulm, 89081
Spain4 sites
Novartis Investigative Site
Barakaldo, 48903
Novartis Investigative Site
Barcelona, 8025
Novartis Investigative Site
Burgos, 90550
Novartis Investigative Site
Madrid, 28034
United Kingdom4 sites
Novartis Investigative Site
Birmingham, B15 2FG
Novartis Investigative Site
Cardiff, CF14 4XW
Novartis Investigative Site
London, WC1N 3BG
Novartis Investigative Site
Manchester, M13 9WL
France3 sites
Novartis Investigative Site
Angers, 49100
Novartis Investigative Site
Marseille, 13385
Novartis Investigative Site
Paris, 75013
Italy3 sites
Novartis Investigative Site
Bologna, 40139
Novartis Investigative Site
Milan, 20133
Novartis Investigative Site
San Giovanni Rotondo, 71013
Australia2 sites
Novartis Investigative Site
Clayton, 3168
Novartis Investigative Site
Westmead, 2145
About this study
Official title: A Phase 2b, Double-Blind, Randomized Extension Study to Evaluate the Long-Term Safety and Efficacy of Votoplam in Participants With Huntington's Disease
The primary goal of this study is to evaluate the long-term safety and pharmacodynamic effects of votoplam in participants with HD.
Read the detailed description
Participants who completed the Treatment Period in the parent Phase 2a Study PTC518-CNS-002-HD (NCT05358717), fulfilled the enrollment criteria, and chose to enroll in this extension study will undergo baseline evaluations and be assessed for 54 additional months.
All participants will receive active votoplam in this extension study. Participants who received votoplam in the parent Study PTC518-CNS-002-HD will continue at the same dose level they received in that study in a blinded fashion (5, 10 milligrams [mg]). Participants who received placebo in the parent Study PTC518-CNS-002-HD will be allocated to a votoplam dose level according to the same dosing group in which they were previously randomized (5, 10 mg).
- Conditions
- Huntington Disease
- Being tested
- Votoplam
- Keywords
- Neurodegenerative disorder, Rare disease
- Medical subject headings
- Huntington Disease, Neurodegenerative Diseases, Rare Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VotoplamDrug
Also called HTT227 / PTC518
Votoplam will be administered per dose and schedule specified in the arm.
| Study group | Role | What they receive |
|---|---|---|
| Votoplam 5 mg | Experimental | Participants will receive Votoplam 5 mg tablets once daily orally for 48 months. Receives: Drug: Votoplam |
| Votoplam 10 mg | Experimental | Participants will receive votoplam 10 mg tablets once daily orally for 48 months. Receives: Drug: Votoplam |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Measured: Baseline up to Month 54
Blood Total Huntingtin Protein (tHTT) Levels
Measured: Baseline up to Month 52
Secondary outcomes (4)
Change From Baseline in Caudate Volume as Assessed Via Volumetric Magnetic Resonance Imaging (vMRI) at Month 48
Measured: Baseline, Month 48
Change From Baseline in Composite Unified Huntington's Disease Rating Scale (cUHDRS) Scores at Month 48
Measured: Baseline, Month 48
Cerebrospinal Fluid (CSF) Mutant Huntingtin Protein (mHTT) Levels
Measured: Baseline up to Month 48
Blood mHTT Protein Levels
Measured: Baseline up to Month 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2024
- Study start25 Aug 2023
- Primary completion16 Jul 2029 (estimated)
- Study completion16 Jul 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Huntington DiseaseStudies of the same condition, open and under way.
- More trials run by Novartis PharmaceuticalsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 144 participants (actual)
Sponsor and investigators
- Lead sponsor
- Novartis Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06254482
- Sponsor's protocol ID
- PTC518-CNS-004-HD
- Other IDs
- 2023-504628-24-00, CHTT227A12201, 2023
- Status last verified
- Nov 2025
- First submitted
- 2 Feb 2024
- Last updated
- 21 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations. This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com
Study at a glance
From the registry record, last updated by the sponsor on 21 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2b, Double-Blind, Randomized Extension Study to Evaluate the Long-Term Safety and Efficacy of Votoplam in Participants With Huntington's Disease
- ClinicalTrials.gov ID
- NCT06254482
- Acronym / sponsor ID
- PTC518-CNS-004-HD
- Conditions
- Huntington Disease
- Keywords
- Neurodegenerative disorder, Rare disease
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 144 participants (actual)
- Lead sponsor
- Novartis PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 25 Aug 2023 (actual)
- Primary completion
- 16 Jul 2029 (estimated)
- Study completion
- 16 Jul 2029 (estimated)
- First posted
- 12 Feb 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary goal of this study is to evaluate the long-term safety and pharmacodynamic effects of votoplam in participants with HD.
Detailed description
Participants who completed the Treatment Period in the parent Phase 2a Study PTC518-CNS-002-HD (NCT05358717), fulfilled the enrollment criteria, and chose to enroll in this extension study will undergo baseline evaluations and be assessed for 54 additional months.
All participants will receive active votoplam in this extension study. Participants who received votoplam in the parent Study PTC518-CNS-002-HD will continue at the same dose level they received in that study in a blinded fashion (5, 10 milligrams [mg]). Participants who received placebo in the parent Study PTC518-CNS-002-HD will be allocated to a votoplam dose level according to the same dosing group in which they were previously randomized (5, 10 mg).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Votoplam 5 mg | Experimental | Drug: VotoplamParticipants will receive Votoplam 5 mg tablets once daily orally for 48 months. |
| Votoplam 10 mg | Experimental | Drug: VotoplamParticipants will receive votoplam 10 mg tablets once daily orally for 48 months. |
Who may qualify
- Ages
- 25 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Participant who has completed the Treatment Period in Study PTC518-CNS-002-HD.
Key exclusion criteria (2 listed)
- Participants who have not previously completed the Treatment Period in Study PTC518-CNS-002-HD.
- Note: Other inclusion and exclusion criteria may apply.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| VotoplamAlso: HTT227 / PTC518Votoplam will be administered per dose and schedule specified in the arm. | Drug | Votoplam 10 mg, Votoplam 5 mg |
Primary outcome
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Time frame: Baseline up to Month 54
Blood Total Huntingtin Protein (tHTT) Levels
Time frame: Baseline up to Month 52
4 secondary outcomes
Change From Baseline in Caudate Volume as Assessed Via Volumetric Magnetic Resonance Imaging (vMRI) at Month 48
Time frame: Baseline, Month 48
Change From Baseline in Composite Unified Huntington's Disease Rating Scale (cUHDRS) Scores at Month 48
Time frame: Baseline, Month 48
Cerebrospinal Fluid (CSF) Mutant Huntingtin Protein (mHTT) Levels
Time frame: Baseline up to Month 48
Blood mHTT Protein Levels
Time frame: Baseline up to Month 52
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Nov 2025.
- Individual participant dataSharing planned: Yes. Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations. This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
24 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Votoplam in people with Huntington Disease, run by Novartis Pharmaceuticals at 24 sites in 10 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 21 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 24 sites in Germany, Spain, United Kingdom, France, Italy and 5 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Treatment-emergent Adverse Events (TEAEs) (time frame: Baseline up to Month 54). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Nov 2025; AzTrials last refreshed its copy on 30 Oct 2026.