An Extension Study to Evaluate the Long-Term Safety and Efficacy of PTC518 in Participants With Huntington's Disease (HD)
- Registration Number
- NCT06254482
- Lead Sponsor
- PTC Therapeutics
- Brief Summary
The primary goal of this study is to evaluate the long-term safety and pharmacodynamic effects of PTC518 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 30 additional months.
All participants will receive active PTC518 in this extension study. Participants who received PTC518 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, or 20 milligrams \[mg\]). Participants who received placebo in the parent Study PTC518-CNS-002-HD will be allocated to a PTC518 dose level according to the same dosing group in which they were previously randomized (5, 10, or 20 mg). The 20 mg dosing arm will be open for randomization only if and when the Data Safety and Monitoring Board from the parent Study PTC518-CNS-002-HD recommends initiating this dosing level based on an unblinded review of safety data from that study.
Recruitment & Eligibility
- Status
- ENROLLING_BY_INVITATION
- Sex
- All
- Target Recruitment
- 250
- Participant who has completed the Treatment Period in Study PTC518-CNS-002-HD.
- Participants who have not previously completed the Treatment Period in Study PTC518-CNS-002-HD.
Note: Other inclusion and exclusion criteria may apply.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description PTC518 5 mg PTC518 Participants will receive PTC518 5 mg tablets once daily orally for 24 months. PTC518 10 mg PTC518 Participants will receive PTC518 10 mg tablets once daily orally for 24 months. PTC518 20 mg PTC518 Participants will receive PTC518 20 mg tablets once daily orally for 24 months.
- Primary Outcome Measures
Name Time Method Blood Total Huntingtin Protein (tHTT) Levels Baseline up to Month 28 Number of Participants With Treatment-emergent Adverse Events (TEAEs) Baseline up to Month 30
- Secondary Outcome Measures
Name Time Method Blood mHTT Protein Levels Baseline up to Month 28 Change From Baseline in Caudate Volume as Assessed Via Volumetric Magnetic Resonance Imaging (vMRI) at Month 24 Baseline, Month 24 Change From Baseline in Composite Unified Huntington's Disease Rating Scale (cUHDRS) Scores at Month 24 Baseline, Month 24 Cerebrospinal Fluid (CSF) Mutant Huntingtin Protein (mHTT) Levels Baseline up to Month 24
Trial Locations
- Locations (24)
Medical University Innsbruck
🇦🇹Innsbruck, Austria
Westmead Hospital
🇦🇺Westmead, Australia
The Ottawa Hospital, Parkinson's and Movement Disorders Clinic
🇨🇦Ottawa, Canada
Centre Hospitalier Universitaire d'Angers
🇫🇷Angers, France
Hôpital Universitaire de Marseille Hôpital de la Timone
🇫🇷Marseille, France
Brain and Spine institute Paris
🇫🇷Paris, France
Ruhr-Univ. Bochum St. Joseph-Hospital
🇩🇪Bochum, Germany
Ulm University, UKU, Dep. of Neurology
🇩🇪Ulm, Germany
George-Huntington-Institut
🇩🇪Münster, Germany
Irccs Istituto Delle Scienze Neurologiche Di Bologna Uoc Clinica Neurologica
🇮🇹Bologna, Italy
IRCCS Carlo Besta Neurological Institutte
🇮🇹Milan, Italy
IRCCS Casa Sollievo della Sofferenza Research Hospital
🇮🇹San Giovanni Rotondo, Italy
Leiden University Medical Center
🇳🇱Leiden, Netherlands
University of Otago, New Zealand Brain Research Institute
🇳🇿Christchurch, New Zealand
Hospital de la Santa Creu I Sant Pau
🇪🇸Barcelona, Spain
Hospital Universitario Cruces
🇪🇸Barakaldo, Spain
Hospital Ramón y Cajal
🇪🇸Madrid, Spain
Hospital Universitario Burgos
🇪🇸Burgos, Spain
University Hospital of Wales
🇬🇧Cardiff, United Kingdom
The Barbery National Centre for Mental Health
🇬🇧Birmingham, United Kingdom
UCL Queen Square Institute of Neurology National Hospital for Neurology and Neurosurgery
🇬🇧London, United Kingdom
Manchester University NHS Foundation Trust
🇬🇧Manchester, United Kingdom
Charite University Medicine Berlin
🇩🇪Berlin, Germany
Monash Health
🇦🇺Clayton, Australia