Pridopidine Phase 3 Study in Huntington's Disease
A Phase 3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Pridopidine in Participants With Huntington's Disease (HD)
- Huntington Disease
At a glance
- Phase
- Phase 3
- Study type
- Interventional
- Sponsor
- Prilenia
- Enrolment target
- 400
- Started
- 1 July 2026
- Main results due
- June 2028
- Study sites
- 66
- Registry updated
- 24 September 2026
Can you take part?
- Ages 23 years to 65 years.
- Open to any sex.
- You need the condition being studied — healthy volunteers are not accepted.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
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.
What this study is about
In the sponsor’s own words, from the registry.
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.
Study sites(66)
The University of Alabama at Birmingham
Birmingham, Alabama, United States
Not yet recruiting
University of California, San Diego
La Jolla, California, United States
Recruiting
UCLA Medical Center
Los Angeles, California, United States
Not yet recruiting
UC Davis Medical Center
Sacramento, California, United States
Not yet recruiting
Georgetown University
Washington D.C., District of Columbia, United States
Not yet recruiting
University of Miami-U Health Boca Raton
Boca Raton, Florida, United States
Not yet recruiting
University of Florida (Norman Fixel Institute for Neurological Diseases)
Gainesville, Florida, United States
Not yet recruiting
Northwestern University
Chicago, Illinois, United States
Not yet recruiting
Rush University Medical Center
Chicago, Illinois, United States
Not yet recruiting
University of Kansas Medical Center
Kansas City, Kansas, United States
Not yet recruiting
Hereditary Neurological Disease Centre
Wichita, Kansas, United States
Recruiting
Johns Hopkins University
Baltimore, Maryland, United States
Not yet recruiting
Massachusetts General Hospital
Charlestown, Massachusetts, United States
Not yet recruiting
Struthers Parkinson's Center / Health Partners Institute
Golden Valley, Minnesota, United States
Not yet recruiting
Columbia University
New York, New York, United States
Not yet recruiting
Duke University
Durham, North Carolina, United States
Recruiting
University of Cincinnati
Cincinnati, Ohio, United States
Not yet recruiting
Cleveland Clinic
Cleveland, Ohio, United States
Not yet recruiting
The Ohio State University
Columbus, Ohio, United States
Recruiting
Oregon Health and Science University (OHSU)
Portland, Oregon, United States
Not yet recruiting
Vanderbilt University Medical Center
Nashville, Tennessee, United States
Recruiting
UT Health, Houston, McGovern Medical School
Houston, Texas, United States
Recruiting
University of Vermont Medical Center
Burlington, Vermont, United States
Not yet recruiting
EvergreenHealth Research Department
Kirkland, Washington, United States
Not yet recruiting
University of Washington
Seattle, Washington, United States
Recruiting
Hopital Erasme
Anderlecht, Belgium
Not yet recruiting
Cliniques Universitaires Saint-Luc
Woluwe-Saint-Lambert, Belgium
Not yet recruiting
University of Calgary
Calgary, Alberta, Canada
Not yet recruiting
University of Alberta
Edmonton, Alberta, Canada
Not yet recruiting
University of British Columbia
Vancouver, British Columbia, Canada
Not yet recruiting
North York General Hospital
Toronto, Ontario, Canada
Not yet recruiting
Centre Hospitalier de l'Universite de Montreal (CHUM)
Montreal, Quebec, Canada
Not yet recruiting
Vseobecna Fakultni Nemocnice V Praze
Prague, Czechia
Not yet recruiting
Centre Hospitalier Universitaire D'Angers
Angers, France
Not yet recruiting
CHU Henri Mondor (APHP)
Créteil, France
Not yet recruiting
Centre Hospitalier Universitaire Grenoble Alpes
La Tronche, France
Not yet recruiting
Centre Hospitalier Regional De Marseille
Marseille, France
Not yet recruiting
Universitaetsklinikum Aachen AöR
Aachen, Germany
Not yet recruiting
Katholisches Klinikum Bochum gGmbH
Bochum, Germany
Not yet recruiting
Universitätsklinikum Erlangen
Erlangen, Germany
Not yet recruiting
George-Huntington-Institut GmbH
Münster, Germany
Not yet recruiting
Isar Amper Klinikum
Taufkirchen, Germany
Not yet recruiting
Universitaetsklinikum Ulm AöR
Ulm, Germany
Not yet recruiting
Azienda Unita Sanitaria Locale Di Bologna
Bologna, Italy
Not yet recruiting
IRCCS Istituto Auxologico Italiano
Milan, Italy
Not yet recruiting
Azienda Ospedaliera Universitaria Federico II Di Napoli
Naples, Italy
Not yet recruiting
Azienda Ospedale Università di Padova
Padova, Italy
Not yet recruiting
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Roma, Italy
Not yet recruiting
Casa Sollievo Della Sofferenza
San Giovanni Rotondo, Italy
Not yet recruiting
Leids Universitair Medisch Centrum (LUMC)
Leiden, Netherlands
Not yet recruiting
Krakowska Akademia Neurologii Sp. z o.o.
Krakow, Poland
Not yet recruiting
Wojskowy Instytut Medycyny Lotniczej
Warsaw, Poland
Not yet recruiting
Unidade Local De Saude De Coimbra E.P.E
Coimbra, Portugal
Not yet recruiting
Unidade Local De Saude De Santa Maria E.P.E.
Lisbon, Portugal
Not yet recruiting
Unidade Local De Saude De Santo Antonio E.P.E.
Porto, Portugal
Not yet recruiting
CNS Saude Lda.
Torres Vedras, Portugal
Not yet recruiting
Hospital Universitario De Cruces
Barakaldo, Spain
Not yet recruiting
Hospital De La Santa Creu I Sant Pau
Barcelona, Spain
Not yet recruiting
Hospital Universitario Ramon Y Cajal
Madrid, Spain
Not yet recruiting
Hospital Universitario Central De Asturias
Oviedo, Spain
Not yet recruiting
Showing 60 of 66 sites — filter to narrow it down. 8 of the 66 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT07609108. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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