Study in PRE-manifest Huntington's Disease of Coenzyme Q10 (UbiquinonE) Leading to Preventive Trials (PREQUEL)

A Multi-Center, Double-Blind, Randomized, Parallel Group Tolerability Study of Coenzyme Q10 (UbiquinonE)in PRE-manifest Huntington's Disease

To establish the tolerability of treatment with 600, 1200 or 2400 mg per day of coenzyme Q10 in pre-manifest participants carrying the CAGn expansion for Huntington's Disease (HD).

secondary objectives:

1. To assess the change from baseline to 20 weeks on biomarkers of oxidative stress (8OHdG and 8OHrG) and DNA repair mechanisms (OGG1) in pre-manifest participants treated with 600, 1200 or 2400 mg per day of CoQ10.
2. To assess the dose-response relationship between CoQ10 at dosages of 600, 1200 or 2400 mg per day and 8OHdG/8OHrG and OGG1.
3. To assess the serum levels of CoQ10 at 600, 1200 or 2400 mg in pre-manifest participants and their relationship to 8OHdG/8OHrG and OGG1.
4. To assess the feasibility of implementing a preventive therapeutic trial in a pre-manifest population.
5. To assess the utility and stability of clinical measures of HD, social relations, behavior and employment in a pre-manifest sample enrolled in a treatment trial.

Inclusion Criteria:

• Participants will be positive for the CAGn expansion in the Huntingtin gene (>36 repeats) and be pre-manifest by virtue of scoring 3 or less on diagnostic confidence level (Question 17 of the UHDRS)
• Participants will have received genetic testing prior to enrollment through a standard pre-manifest testing protocol.
• 18 years of age or older.
• Concomitant medications are permitted with the exception of CoQ10, creatine > 5g/day and warfarin.

Exclusion Criteria:

• History of intolerability to CoQ10.
• CoQ10 use within 60 days prior to randomization.
• Unstable medical or psychiatric illness;
• Substance abuse within one year of the baseline visit.
• Pregnancy, breastfeeding or lack of reliable contraception in women of childbearing age.
• Subjects with known allergy to FD&C #6 yellow food coloring.