Results of an interim analysis showed that it was unlikely that creatine was effective in slowing loss of function in early symptomatic Huntington's Disease.

Huntington's disease (HD) is a slowly progressive disorder that devastates the lives of those affected and their families. There are no treatments that slow the progression of HD, only mildly effective symptomatic therapies are available.Creatine monohydrate is considered a nutritional supplement. The purpose of CREST-E is to test whether high-dose creatine can slow the progressive functional decline that occurs in persons 18 years or older with early clinical features of HD. The long-term safety, tolerability and effectiveness of up to 40 grams daily creatine compared to placebo is studied. A variety of biological processes are assessed for markers of disease activity or progression and creatine effects. Up to 50 active research centers globally will enroll 650 subjects.

Inclusion Criteria:

• Male or female ages 18 or older.
• Clinical features of HD AND confirmatory family history of HD; OR Clinical features of HD AND CAG repeat expansion greater or equal to 36.
• Stage I or II of illness (TFC greater or equal to 7).
• Ambulatory and not requiring skilled nursing care at the time of enrollment.
• Must be capable of providing informed consent and complying with trial procedures.
• Additional inclusion criteria apply.

Exclusion Criteria:

• History of known sensitivity or intolerability to creatine monohydrate.
• Exposure to any investigational drug within 30 days of randomization (Baseline visit).
• Use of supplemental creatine at a dose greater than 10 grams within 30 days of randomization (Baseline visit).
• Screening laboratory abnormalities that in the judgment of the investigator would jeopardize safe conduct of study.
• Clinical evidence of unstable medical illness.
• Clinical evidence of unstable psychiatric illness.
• Additional exclusion criteria apply.