A Study to Evaluate the Safety and Efficacy of PTC518 in Participants With Huntington's Disease (HD)

NCT ID: NCT05358717

Last Updated: 2026-01-13

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

View full results

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

PHASE2

Total Enrollment

159 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-06-03

Study Completion Date

2025-07-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The primary goal of this study is to evaluate the safety and pharmacodynamic effects of PTC518 compared with placebo in participants with HD.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Participants will first be randomized to Part A or Part B or Parts D or E in a 1:1 randomization ratio, depending on their Huntington's disease Integrated Staging System (HD-ISS) staging criteria and then to active treatment (PTC518 5 mg in Parts A and D and 10 mg in Parts B and E) or matching placebo within each part in a 2:1 ratio of active treatment to placebo. A Drug Safety Monitoring Board (DSMB) Charter will undertake an unblinded review of safety data from the 5 and 10 mg dosing groups and provide a recommendation on when Parts C and F (with a 20 mg active treatment arm) can be initiated. At that time, participants will be randomized to any study Part that is currently open for enrollment, and then to either active treatment or placebo (in a 2:1 ratio) within that Part.

Participants who complete this study and agree to participate in a long-term extension (LTE) study, will be enrolled in a separate LTE study PTC518-CNS-004-HD (NCT06254482).

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Huntington Disease

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Participants Investigators

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

PTC518 5 mg

Participants will receive PTC518 5 milligrams (mg) tablets once daily orally for 12 months.

Group Type EXPERIMENTAL

PTC518

Intervention Type DRUG

PTC518 will be administered per dose and schedule specified in the arm.

PTC518 10 mg

Participants will receive PTC518 10 mg tablets once daily orally for 12 months.

Group Type EXPERIMENTAL

PTC518

Intervention Type DRUG

PTC518 will be administered per dose and schedule specified in the arm.

PTC518 20 mg

Participants will receive PTC518 20 mg tablets once daily orally for 12 months.

Group Type EXPERIMENTAL

PTC518

Intervention Type DRUG

PTC518 will be administered per dose and schedule specified in the arm.

Placebo

Participants will receive placebo matching to PTC518 tablets once daily orally for 12 months.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type DRUG

Placebo matching to PTC518 will be administered per schedule specified in the arm.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

PTC518

PTC518 will be administered per dose and schedule specified in the arm.

Intervention Type DRUG

Placebo

Placebo matching to PTC518 will be administered per schedule specified in the arm.

Intervention Type DRUG

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Genetically confirmed HD diagnosis with a cytosine-adenine-guanine (CAG) repeat length from 40 to 50, inclusive

Eligibility for HD-ISS Stage 2 Group (Parts A, B, and C):

* A Unified Huntington's Disease Rating Scale (UHDRS)-Independence Scale (IS) score of 100
* A UHDRS Total Functional Capacity (TFC) score of 13
* A score between 0.18 and 4.93 inclusive on the normed version of the HD prognostic index (PINHD)

Eligibility for HD-ISS Mild Stage 3 Group (Parts D, E, and F):

* A UHDRS Total Functional Capacity (TFC) score of 11 or 12, or a UHDRS TFC score of 13 with an UHDRS IS score of \<100

Exclusion Criteria

* Receipt of an experimental agent within 90 days or 5 half-lives prior to Screening or anytime over the duration of this study, ribonucleic acid (RNA)- or deoxyribonucleic acid (DNA)-targeted HD-specific investigational agents such as antisense oligonucleotides, cell transplantation, or any other experimental brain surgery
* Any history of gene therapy exposure for the treatment of HD
* Participation in an investigational study or investigational paradigm (such as exercise/physical activity, cognitive therapy, brain stimulation, etc) within 90 days prior to Screening or anytime over the duration of this study
* Any medical history of brain or spinal disease that would interfere with the lumbar puncture process safety assessments
* Any medical history or condition that would interfere with the ability to complete the protocol-specified assessments (for example, implanted shunt, conditions precluding magnetic resonance imaging \[MRI\] scans)
* Pregnancy, planning on becoming pregnant during the course of the study or within 6 months of end of treatment, or currently breastfeeding
Minimum Eligible Age

25 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

PTC Therapeutics

INDUSTRY

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

University of California, San Diego

La Jolla, California, United States

Site Status

Vanderbilt University Medical Center

Nashville, Tennessee, United States

Site Status

The University of Texas Health Science Center at Houston; McGovern Medical School

Houston, Texas, United States

Site Status

University of Washington Department of Neurology

Seattle, Washington, United States

Site Status

Monash Health

Clayton, , Australia

Site Status

Westmead Hospital

Sydney, , Australia

Site Status

Medical University Innsbruck

Innsbruck, , Austria

Site Status

The Ottawa Hospital, Parkinson's and Movement Disorders Clinic

Ottawa, , Canada

Site Status

Centre Hospitalier Universitaire d'Angers

Angers, , France

Site Status

Hôpital Universitaire de Marseille Hôpital de la Timone

Marseille, , France

Site Status

Brain and Spine Institute Paris

Paris, , France

Site Status

Charite University Medicine Berlin

Berlin, , Germany

Site Status

Ruhr-Univ. Bochum St. Joseph-Hospital

Bochum, , Germany

Site Status

George-Huntington-Institut

Münster, , Germany

Site Status

Ulm University, UKU, Dep. of Neurology

Ulm, , Germany

Site Status

Irccs Istituto Delle Scienze Neurologiche Di Bologna Uoc Clinica Neurologica

Bologna, , Italy

Site Status

IRCCS Carlo Besta Neurological Institutte

Milan, , Italy

Site Status

IRCCS Casa Sollievo della Sofferenza Research Hospital

San Giovanni Rotondo, , Italy

Site Status

Leiden University Medical Center

Leiden, , Netherlands

Site Status

University of Otago, New Zealand Brain Research Institute

Christchurch, , New Zealand

Site Status

Hospital Universitario Cruces

Barakaldo, , Spain

Site Status

Hospital de la Santa Creu I Sant Pau

Barcelona, , Spain

Site Status

Hospital Universitario Burgos

Burgos, , Spain

Site Status

Hospital Ramón y Cajal

Madrid, , Spain

Site Status

The Barbery National Centre for Mental Health

Birmingham, , United Kingdom

Site Status

Cardiff University Schools of Medicine and Biosciences

Cardiff, , United Kingdom

Site Status

UCL Queen Square Institute of Neurology National Hospital for Neurology and Neurosurgery

London, , United Kingdom

Site Status

Manchester University NHS Foundation Trust

Manchester, , United Kingdom

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United States Australia Austria Canada France Germany Italy Netherlands New Zealand Spain United Kingdom

References

Explore related publications, articles, or registry entries linked to this study.

Estevez-Fraga C, Tabrizi SJ, Wild EJ. Huntington's Disease Clinical Trials Corner: March 2024. J Huntingtons Dis. 2024;13(1):1-14. doi: 10.3233/JHD-240017.

Reference Type DERIVED
PMID: 38489195 (View on PubMed)

Estevez-Fraga C, Tabrizi SJ, Wild EJ. Huntington's Disease Clinical Trials Corner: November 2022. J Huntingtons Dis. 2022;11(4):351-367. doi: 10.3233/JHD-229006.

Reference Type DERIVED
PMID: 36463457 (View on PubMed)

Provided Documents

Download supplemental materials such as informed consent forms, study protocols, or participant manuals.

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

2021-003852-18

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

PTC518-CNS-002-HD

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.