Clinical trial Recruiting at 12 sites Phase1; Phase2 Interventional Ages 25 to 60

Testing a new drug VO659 for genetic neurodegenerative diseases

Official title: A Phase 1/2a, Open-label Trial to Investigate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Multiple Ascending Doses of Intrathecally Administered VO659 in Participants With Spinocerebellar Ataxia Types 1, 3 and Huntington's Disease

Run by Vico Therapeutics B. V. · NCT05822908 · Data updated 2026-11-12

This study is testing a new drug called VO659 to see if it is safe and can help people with spinocerebellar ataxia types 1 and 3 or Huntington's disease.

More Huntington Disease trials

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Ages25 Years to 60 Years
SexAll
Enrollment68 (estimated)
SponsorVico Therapeutics B. V.
Industry-sponsored
Locations14 sites (Copenhagen and 13 other locations)
StatusRecruiting
StartedFebruary 14, 2023
Main results expectedApril 1, 2028
Study endsOctober 15, 2028
Registry record updatedAugust 19, 2026
Trial IDNCT05822908 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are adults aged 25 to 60 with genetically confirmed mild to moderate spinocerebellar ataxia types 1 or 3, or early-stage Huntington's disease.

Probably not a fit

Patients with advanced stages of these diseases or those outside the specified age range may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial aims to evaluate the safety and tolerability of the drug VO659 in patients with spinocerebellar ataxia types 1 and 3, as well as Huntington's disease. It is a first-in-human, open-label, multiple ascending dose trial that will assess the pharmacokinetics of the drug after intrathecal administration. Participants will be assigned to different dose cohorts based on their enrollment order, with a total trial duration of approximately 42 weeks. The study will focus on individuals with mild to moderate symptoms of these conditions, aiming to gather data on the drug's effects on disease progression.

Why it matters

Potential benefit: If successful, this trial could lead to a new treatment option that may slow or halt the progression of debilitating neurodegenerative diseases.

How similar studies have gone: While this approach is novel in humans, preclinical data suggest potential efficacy, indicating a promising avenue for treatment.

Who can join: the full rules

Show full inclusion / exclusion criteria
Main Inclusion Criteria:

* Provide written informed consent (signed and dated). Patients should be assessed for their ability to give informed consent using the Evaluation to Sign Consent tool.
* Is ≥25 and ≤60 years of age inclusive, of any gender, at the time of signing the informed consent.
* Have SCA1, SCA3 or HD meeting one of the following criteria:

  1. SCA1 and SCA3: mild to moderate disease with a Scale for Assessment and Rating of Ataxia (SARA) score of ≥3 and ≤18
  2. HD: early manifest, Stage I disease with a Total Functional Capacity (TFC) Score of ≥11 and ≤13 and a Unified Huntington's Disease Rating Scale (UHDRS) Diagnostic Confidence Level (DCL) of 4.
* Have genetically confirmed disease, defined by increased cytosine, adenine, and guanine (CAG) repeat length in the disease-causing allele by direct DNA testing. For each indication the requirements are:

  1. SCA1: ≥41 contiguous, uninterrupted CAG repeats in the ATXN1 gene
  2. SCA3: ≥61 repeats in the ATXN3 gene
  3. HD: ≥40 CAG repeats in the HTT gene.
* Please note there will be additional inclusion criteria

Main Exclusion Criteria:

* Have any condition that would prevent participation in trial assessments.
* Have one or more pathogenic mutation(s) in another polyQ disease gene, i.e., ATXN2, CACNA1A, ATXN7, TBP, AR, and ATN1, plus either ATXN3 and HTT (for patients with SCA1), ATXN1 and HTT (for participants with SCA3), or ATXN1 and ATXN3 (for participants with HD), in addition to the disease-causing mutation in the ATXN1 (patients with SCA1), ATXN3 (patients with SCA3) or HTT (patients with HD) gene.
* Have clinical diagnosis of moderate or severe chronic migraines or history of the post-lumbar-puncture headache of moderate or severe intensity requiring hospitalisation or blood patch.
* Have a brain, spinal or systemic disorder that would interfere with the LP process, CSF circulation, or safety assessments.
* Have history of bleeding diathesis or coagulopathy, platelet count less than the lower limit of normal unless stable and assessed by the investigator and the Medical Monitor to be not clinically significant.
* Have uncompensated cardiovascular disorder, any past or present cardiac arrhythmia, QTcF values on screening ECG of \>470 ms, familial history of long QT syndrome or sudden unexpected death.
* Have a history of attempted suicide, suicidal ideation with a plan that required hospital admission and/or change in level of care within 12 months prior to screening.
* Have medical, psychiatric, or other conditions that, in the judgement of the investigator, may compromise the patient's ability to understand the patient information sheet, to give informed consent, to comply with all trial requirements, or to complete the trial.
* Prior treatment with an antisense oligonucleotide (including siRNA).
* Pregnant or breast-feeding (lactating) women or women who plan to become pregnant or breast-feed during the trial.
* Unable to undergo and tolerate MRI scans.
* Please note there will be additional exclusion criteria

Where it's running

  • Rigshospitalet
    Copenhagen, Denmark
    Recruiting
  • Centre Hospitalier Universitaire dÁngers
    Angers, France
    Recruiting
  • CHU Gui de Chauliac Montpellier- Expert Center of Neurogenetic diseases, Department of Neurology
    Montpellier, France
    Recruiting
  • Universtiry Hospitals Pitie Salpetriere - Charles foix - Paris
    Paris, France
    Recruiting
  • Katholisches Klinikum Bochum
    Bochum, Germany
    Recruiting
  • Deutsches Zentrum fur Neurodegenerative Erkrankungen (DZNE)
    Bonn, Germany
    Recruiting
Show 8 more locations
  • Universitatsklinikum Essen - Neurologie
    Essen, Germany
    Recruiting
  • Universitatsklinikum Tübingen
    Tübingen, Germany
    Recruiting
  • Meir Medical Center
    Kfar Saba, Israel
    Recruiting
  • Sourmansky Medical Center
    Tel Aviv, Israel
    Recruiting
  • University College London Hospitals NHS Foundation
    London, United Kingdom
    Recruiting
  • John Radcliffe Hospital
    Oxford, United Kingdom
    Recruiting
  • Leiden University Medical Center LUMC
    Leiden, Netherlands
    Active not recruiting
  • Radbout University Medical Centre
    Nijmegen, Netherlands
    Active not recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.