Study to Evaluate the Pharmacodynamics, Safety and Efficacy of SKY-0515 in Participants With Huntington's Disease

Prior treatment

• 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.

Other illness

• 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.
• History of suicidal thoughts, severe depression, or have attempted suicide in the past year.
• Positive for hepatitis B, hepatitis C, or HIV.

Other

• Other Serious health problems or brain/spinal issues that could interfere with the study or make procedures unsafe.
• Liver function tests show significant abnormalities.
• Pregnancy, breastfeeding, or planning to become pregnant during the study.

• 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.