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Taking peoplePhase 3

Pridopidine Tested in Adults With Huntington's Disease

Tests whether pridopidine slows worsening of Huntington's disease in adults over one year.

Key facts

Who runs it
Prilenia
Where
Prague, CzechiaSee the siteAlso in 11 other countries, 65 sites
Registry title
Pridopidine Phase 3 Study in Huntington's Disease
Status
Recruiting
Phase
Phase 3
People taking part
400 people, planned
Started
1 Jul 2026
Expected to end
Jun 2030
Type of study
Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • Pridopidine
  • Placebo
Record updated
4 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with Huntington's disease to test whether pridopidine slows the worsening of the disease over 1 year compared with placebo.

Age
23 to 65 years
Sex
All sexes can join.
Disease stage
Adult-onset Huntington's disease (signs and diagnosis at 21 years or older), with clear motor signs, a Total Functional Capacity score of 7 or more and a Total Motor Score of 20 or more.
Earlier treatment
Must not have used anti-chorea medicines (VMAT2 inhibitors, neuroleptics or antipsychotics) for at least 6 months before screening. Must not have had any mutant huntingtin lowering therapy in the past year.
Biomarker or test result
40 or more CAG repeats in the huntingtin (HTT) gene, shown by earlier lab results or a test at screening.

Main reasons for not taking part

  • Significant heart disease, such as long QT or uncontrolled atrial fibrillation
  • Seizures within the last 5 years
  • Severe liver or kidney problems
  • Previous participation in an intracranial gene therapy study
  • Pregnant, planning to become pregnant or breastfeeding

The registry criteria, word for word

Show all 16 criteriaShow less

Who can take part

  • Adult-onset HD (onset of signs and symptoms and a clinical diagnosis at ≥21 years of age)
  • A diagnosis based on clinical features and the presence of ≥40 CAG repeats in the huntingtin (HTT) gene confirmed by historical laboratory quanitified results or by a diagnostic test at Screening
  • Diagnostic confidence level (DCL) of 4 (DCL=4 unequivocal motor signs, ≥99% confidence) on the standardized motor exam Total Motor Score (TMS)
  • Total Functional Capacity (TFC) score of ≥7 at Screening and Baseline
  • Cytosine-Adenine-Guanine (CAG)-Age Product (CAP)100 score ≥95 at Screening
  • Independence Scale (IS) score ≤90% at Screening
  • Total Motor Score (TMS) of ≥20 at Screening and Baseline
  • Not using ADMs (VMAT2i and neuroleptics/antipsychotics) for at least 6 months prior to Screening visit. Importantly, it is not encouraged to discontinue the participants' ADM treatment solely for enrollment in the current trial

Who cannot take part

  • Any mutant huntingtin (mHTT) lowering therapy in the past year
  • Previous participation in intracranial gene therapy study
  • Severe hepatic or renal impairment
  • Clinically significant cardiovascular disease (e.g. QTcF >450 msec [males] or >470 msec [females], arrhythmias, uncontrolled atrial fibrillation, or congenital long QT syndrome), seizure history ≤5 years, significant neurological disorders (e.g. intracranial pathology or cerebrovascular events), active/recent malignancy (unless localized and resolved), or any serious or uncontrolled systemic disease (e.g. hepatic, renal, respiratory, endocrine, infectious [HBV, HCV, HIV], or psychiatric) that may pose safety risk or interfere with participation
  • Medications that prolong QT interval, taken within 4 weeks of the baseline visit
  • Laboratory values that fall outside of the central laboratory's reference range at Screening and are considered clinically significantly abnormal by the Investigator and affect the participant's suitability to participate in the study or put the participant at risk if he/she enters the study in the Investigator's opinion
  • Use of pridopidine within 6 weeks or 5 half-lives before the screening visit
  • Female participants who are pregnant, planning to become pregnant or breastfeeding

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 23 and 65 years old?

Where in Czechia

Also in 11 other countries, 65 sites

  • Vseobecna fakultni nemocnice v PrazePrague, CzechiaNot yet recruiting

About the trial

What the trial wants to find out

The goal of this clinical trial is to learn if pridopidine can slow the clinical decline of Huntington's Disease (HD) in adult participants. It will also inform about the safety of pridopidine.

Read full original descriptionShow less

The main questions the study aims to answer are:

Does pridopidine slow the overall worsening of HD over 1 year? Does pridopidine slow the worsening of specific aspects of HD over 1 year, namely the clinical progression, the ability to perform daily life activities (functional capacity), the mind's ability to process information (cognition), working of the muscles (motor function), and quality of life?

Researchers will compare the drug pridopidine to a placebo (a look-alike substance that contains no drug) to see if pridopidine works better than placebo to treat HD. During the first year of the study, participants will have the same chance to receive either pridopidine or placebo.

Participants will:

Take 1 pridopidine or placebo capsule twice daily for 12 months. Visit the clinic 6 times within 1 year for checkups and tests.

All participants who complete this 1-year placebo-controlled study period will roll over into an additional 2-year study period during which all participants will receive pridopidine treatment, including participants who had received placebo during the first year. During this additional 2-year treatment period participants will visit the clinic a total of 6 times for checkups and tests.

The 2 groups in the trial

  • PridopidineTreatment being tested

    During the titration period (2 weeks), pridopidine 45 mg capsules will be taken orally once daily (in the morning) for 2 weeks. Afterwards, pridopidine 45 mg capsules will be taken orally twice daily (in the morning and in the afternoon; 7-10 hours apart) for 50 weeks.

  • PlaceboPlacebo, for comparison

    During the titration period (2 weeks), matched placebo hard gelatin capsules will be taken once daily (in the morning) for 2 weeks. Afterwards, placebo capsules will be taken twice daily (in the morning and in the afternoon; 7-10 hours apart) for 50 weeks.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Phase 3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Pridopidine in Participants With Huntington's Disease (HD)
Plain-language title
Pridopidine Tested in Adults With Huntington's DiseaseGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Fit questions
Built from NCT07609108, who can take part
Record updated
4 November 2026