Clinical trial Recruiting at 19 sites Phase2; Phase3 Interventional Ages 25 and up

SKY-0515 for adults with Huntington's disease

Official title: A Phase 2/3 Randomized, Double Blind, Placebo-Controlled, Dose Ranging Study to Evaluate the Pharmacodynamics, Safety and Efficacy of SKY-0515 in Participants With Huntington's Disease

Run by Skyhawk Therapeutics, Inc. · NCT07378644 · Data updated 2026-11-12

This trial will test whether the oral drug SKY-0515 can lower harmful huntingtin protein and improve symptoms in adults aged 25 and older with genetically confirmed Huntington's disease.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Ages25 Years and up
SexAll
Enrollment400 (estimated)
SponsorSkyhawk Therapeutics, Inc.
Industry-sponsored
Locations31 sites (Englewood, Colorado and 30 other locations)
StatusRecruiting
StartedJanuary 6, 2026
Main results expectedDecember 2028
Study endsAugust 2029
Registry record updatedNovember 6, 2026
Trial IDNCT07378644 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults aged 25 or older with genetically confirmed Huntington's disease (CAG repeat ≥ 40) who meet the trial's motor and functional thresholds (TFC ≥ 10, TMS ≥ 6, IS ≥ 70) and can comply with imaging, blood tests, and contraception rules are ideal candidates.

Probably not a fit

People with more advanced disease below the functional/motor cutoffs, significant comorbidities, MRI contraindications, current pregnancy, or who cannot meet contraception requirements are unlikely to benefit or will be ineligible.

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

What this trial studies

This is a randomized, double-blind, placebo-controlled, multi-site trial testing an oral small molecule, SKY-0515, across three dose levels versus placebo. SKY-0515 is designed to reduce both mutant and wild-type huntingtin (HTT) protein levels and to lower PMS1, a protein linked to somatic CAG repeat expansion that drives disease progression. Eligible participants are adults (25+) with genetically confirmed HD (CAG ≥ 40) who meet specified motor and functional thresholds and can undergo MRI and required safety monitoring. Safety, pharmacodynamic markers in blood, MRI measures, and clinical outcomes including the UHDRS will be used to compare the treatment arms to placebo.

Why it matters

Potential benefit: If successful, SKY-0515 could lower disease-driving huntingtin levels and slow symptom progression or improve function for people with HD.

How similar studies have gone: Gene-silencing approaches (like antisense oligonucleotides) have shown reduction of mutant huntingtin protein in humans with mixed clinical effects, while an oral small-molecule approach targeting HTT and PMS1 is relatively novel and less tested in patients.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 25 years or older.
* Huntington's Disease confirmed through genetic testing, with a specific change in exon 1 of the HTT gene (CAG repeat of 40 or more).
* Total Functional Capacity (TFC) score of 10 or more).
* Total Motor Score (TMS) of 6 or more).
* Independence Score (IS) of 70 or more).
* Women who can have children must have a negative pregnancy test before starting and use two types of birth control during the study and for 30 days after the last dose of the study drug.
* Men must agree to use birth control during the study and for 90 days after the last dose.
* Agree to sign a consent form and follow the study's rules and schedule.

Exclusion Criteria:

* Other Serious health problems or brain/spinal issues that could interfere with the study or make procedures unsafe.
* Conditions that interfere with protocol-specified assessments, like an implanted medical device or difficulty getting an MRI.
* Cancer, except for some types of skin cancer, or a history of cancer in the last five years.
* Severe allergies or have reacted badly to similar drugs in the past.
* Taking medications or treatments that might interfere with the study.
* Participated in another study or taken experimental drugs in the last two months (or longer for some drugs).
* Any kind of gene therapy.
* History of suicidal thoughts, severe depression, or have attempted suicide in the past year.
* Liver function tests show significant abnormalities.
* Positive for hepatitis B, hepatitis C, or HIV.
* Pregnancy, breastfeeding, or planning to become pregnant during the study.

Where it's running

  • CenExel Denver CO
    Englewood, Colorado, United States
    Recruiting
  • Hospital El Cruce
    Buenos Aires, Buenos Aires, Argentina
    Recruiting
  • Buenos Aires British Hospital
    Caba, Buenos Aires, Argentina
    Recruiting
  • IADIN (Instituto Argentino de Investigación Neurológica)
    Caba, Buenos Aires, Argentina
    Recruiting
  • CINME Centro de Investigaciones Metabólicas
    Caba, Buenos Aires, Argentina
    Recruiting
  • Sanatorio Mater Dei
    Caba, Buenos Aires, Argentina
    Recruiting
Show 25 more locations
  • Fundación Scherbovsky
    Mendoza, Mendoza Province, Argentina
    Recruiting
  • Hospital Angelina Caron
    Campina Grande do Sul, Paraná, Brazil
    Recruiting
  • PUCPR - Centro de Pesquisa da Pontifícia Universidade Católica do Paraná
    Curitiba, Paraná, Brazil
    Recruiting
  • Instituto de Neurologia de Curitiba
    Curitiba, Paraná, Brazil
    Recruiting
  • Hospital Universitario Pedro Ernesto (HUPE)
    Rio de Janeiro, Rio de Janiero, Brazil
    Recruiting
  • North York General Hospital
    Toronto, Ontario, Canada
    Recruiting
  • Pontificia Universidad Católica de Chile
    Santiago, Santiago Metropolitan, Chile
    Recruiting
  • CETRAM (Centro de Trastornos del Movimiento)
    Santiago, Santiago Metropolitan, Chile
    Recruiting
  • Clínica de la Costa S.A.S
    Barranquilla, Atlántico, Colombia
    Recruiting
  • Pineo Medical Ecosystem
    Tbilisi, Georgia
    Recruiting
  • Simon Khechinashvili University Hospital
    Tbilisi, Georgia
    Recruiting
  • NeuroClnx
    Motherwell, Lanarkshire, United Kingdom
    Recruiting
  • University College of London
    London, United Kingdom
    Recruiting
  • Beth Israel Deaconess Medical Center
    Boston, Massachusetts, United States
    Not yet recruiting
  • Massachusetts General Hospital
    Charlestown, Massachusetts, United States
    Not yet recruiting
  • The Ohio State University
    Columbus, Ohio, United States
    Not yet recruiting
  • Centro de Pesquisas Clínicas do Hospital das Clínicas da Universidade Federal de Minas Gerais - Filial EBSERH
    Belo Horizonte, Minas Gerais, Brazil
    Enrolling by invitation
  • Hospital Universitário Onofre Lopes (HUOL)
    Natal, Rio Grande do Norte, Brazil
    Not yet recruiting
  • Faculdade de Medicina de Ribeirão Preto - FMRP
    Ribeirão Preto, São Paulo, Brazil
    Not yet recruiting
  • Hospital da Universidade Federal de São Paulo - UNIFESP
    São Paulo, São Paulo, Brazil
    Not yet recruiting
  • PSEG Centro de Pesquisa Clinica
    São Paulo, São Paulo, Brazil
    Active not recruiting
  • Isar-Amper-Klinikum, Zentrum für Neuro- und Gerontopsychiatrie (ZNGP)
    Taufkirchen, Germany
    Not yet recruiting
  • Hospital Universitario Ramon y Cajal
    Madrid, Madrid, Spain
    Not yet recruiting
  • Hospital Clinic de Barcelona
    Barcelona, Spain
    Not yet recruiting
  • Sant Pau Hospital
    Barcelona, Spain
    Not yet recruiting

Study contacts

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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.
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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.