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

Prior treatment

• You are taking medications or treatments that might interfere with the study.
• You've been in another study or taken experimental drugs in the last two months (or longer for some drugs).
• You have had any kind of gene therapy.

Other illness

• You have a condition that interferes with protocol-specified assessments, like an implanted medical device or difficulty getting an MRI.
• You have cancer, except for some types of skin cancer, or a history of cancer in the last five years.
• You have severe allergies or have reacted badly to similar drugs in the past.
• You have a history of suicidal thoughts, severe depression, or have attempted suicide in the past year.
• You have tested positive for hepatitis B, hepatitis C, or HIV.

Other

• You have other serious health problems or brain/spinal issues that could interfere with the study or make procedures unsafe.
• Your liver function tests show significant abnormalities.
• You are pregnant, breastfeeding, or planning to become pregnant during the study.

• You must be 25 years or older.
• You must have Huntington's Disease confirmed through genetic testing, with a specific gene change (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.
• You must agree to sign a consent form and follow the study's rules and schedule.