This study is designed to determine the effect of 2 gram/day of ethyl-EPA on motor (movement) signs and symptoms of Huntington disease.

Multi-center, double blind, placebo-controlled study with parallel groups of outpatients with early, symptomatic Huntington's disease. Participants will be randomized to receive 1 gram twice daily (2 gram/day total daily dose) of active study drug or placebo. The 6-month placebo-controlled phased will be followed by a subsequent 6-month open-label extension phase with all subjects receiving 1 gram twice daily (2 grams/day total daily dose) of active study drug.

Inclusion Criteria:

• Clinical features of Huntington's disease (HD) and confirmatory family history of HD, and/or CAG repeat expansion greater than or equal to 36
• Ambulatory, not requiring skilled nursing care (total functional capacity [TFC] greater than or equal to 7)
• Chorea score of at least 2 in one extremity (UHDRS)
• Maximal dystonia less than or equal to 2 and maximal bradykinesia less than or equal to 2
• 35 years of age or older of either gender
• Must be on stable dosages of non-competitive NMDA receptor antagonists, and/or antiepileptic medications for 60 days prior to baseline
• Females of child-bearing potential must use adequate birth control

Exclusion Criteria:

• History of established diagnosis of tardive dyskinesia
• Clinical evidence of unstable medical or psychiatric illness
• Clinically significant active and unstable psychotic disease (hallucinations or delusions)
• Major depression (Beck Depression Inventory [BDI]-II Score greater than 20) at Screening Visit
• Suicidal ideation (BDI-II item 9 greater than or equal to 2) at Screening Visit
• History of clinically significant substance abuse within 12 months of Baseline Visit
• Pregnant/lactating women
• Participation in other drug studies within 60 days prior to Baseline Visit
• Previous participation in any investigational study of ethyl-EPA (Miraxion™)
• Use of aspirin at daily dosage greater than 325 mg/day
• Exclusionary Drugs (within 6 months Baseline Visit): Depot neuroleptics
• Exclusionary Drugs (within 60 days Baseline Visit): Omega-3 supplementation, tetrabenazine or reserpine, high dose and/or variable dose oral anti-psychotic medications, steroid (other than topical), selenium supplements greater than 55 mcg/day, lithium, benzodiazepines (except for low dose), anticoagulants