NCT07609108 · Prilenia
Pridopidine Phase 3 Study in Huntington's Disease
(PRECISE-HD)
What this study is about
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.
View original scientific description
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. 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.
Interventions
DRUG
Pridopidine
Pridopidine hard gelatin capsule
DRUG
Placebo
Matched placebo hard gelatin capsule
Primary outcome measures
Change in Composite Unified Huntington's Disease Rating Scale (cUHDRS)
Time frame: Change from Baseline to Week 52
cUHDRS is a combined score to assess disease progression in HD. It includes TFC, TMS, SDMT, and SWR: Total Functional Capacity (TFC) tests the capacity to maintain daily living, finances, care level, occupation. Higher score = better outcome. Best score=13. Worst score=0. Total Motor Score (TMS) assesses motor features (oculomotor, dysarthria, chorea, dystonia, gait, postural stability). Higher score = worse outcome. Best score=0. Worst score= 124. Stroop Word Reading (SWR) measures attention and mental flexibility. Participant reads names of colors printed in black ink. Scores reflect correct responses in 45 sec. Higher score = better outcome. Best score=100. Worst score=0. Symbol Digit Modalities Test (SDMT) tests psychomotor speed and working memory. Participant has 90 sec to match numbers with symbols. Scores = correct answers in 90 sec. Higher score = better outcome. Best score=120. Worst score=0. Total integrated cUHDRS scale range: -7.6 to 24.8. The higher, the better.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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.
Exclusion criteria
- 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.
- Severe hepatic or renal impairment.
- Any mutant huntingtin (mHTT) lowering therapy in the past year.
- Medications that prolong QT interval, taken within 4 weeks of the baseline visit.
- Use of pridopidine within 6 weeks or 5 half-lives before the screening visit.
- Previous participation in intracranial gene therapy study.
- 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.
- Female participants who are pregnant, planning to become pregnant or breastfeeding.
Where
- Birmingham, Alabama
- La Jolla, California
- Los Angeles, California
- Sacramento, California
- Washington D.C., District of Columbia
- Boca Raton, Florida
- Gainesville, Florida
- Chicago, Illinois
- Kansas City, Kansas
- Wichita, Kansas
- Baltimore, Maryland
- Charlestown, Massachusetts
And 12 more locations — see the full list below.
Collaborators
Ferrer Internacional S.A.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 7, 2026 · Source of record for eligibility and locations