Creatine Safety, Tolerability, & Efficacy in Huntington's Disease (CREST-E)

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.