The primary objective of this study is to provide biological samples from patients with Huntington's disease to allow characterisation of the pharmacological mechanism of action of SEN0014196.

This study will establish the acute phenotypical and biological effects of repeated dose application of SEN0014196 in patients with Huntington's disease, providing biomaterials for biomarker studies (levels of circulating huntingtin, acetylation status of mutant huntingtin, innate immune markers, transcriptional profiles). Evaluation of phenotypic effects will include UHDRS scores, total functional capacity. Safety assessments will include ECG, vital signs, laboratory safety tests and physical examination.

Inclusion Criteria:

• Patients with early Huntington's Disease (age: 18 to 70 years), i.e. genetically confirmed (CAG repeat length ≥36) HD, motor signs of HD (motor score of the UHDRS > 5) and a TFC of ≥7.
• All patients will have a body weight greater than 50 kg.
• Female subjects must be surgically sterile or post-menopausal, no spontaneous menstruation for at least one year before the first dose, non-lactating and have a negative urine pregnancy test. Male subjects participating in the trial and their female contraception from the time of taking the first dose of the study drug until three months after taking the last dose. This must include a condom or other barrier method.
• All subjects must be capable of providing written informed consent.
• Subjects must have no clinically significant and relevant history that could affect the conduct of the study and evaluation of the data, as ascertained by the Investigator through detailed medical history and screening assessments.

Exclusion Criteria:

• Participation in a study of an investigational drug within 30 days of the baseline visit.
• Subjects with presence of psychosis and/or confusional states.
• Subjects with clinically significant laboratory or ECG abnormalities at Screening.
• Subjects with clinically relevant hematological, hepatic, cardiac or renal disease.
• A medical history of infection with human immunodeficiency virus, hepatitis C and/or hepatitis B.
• Any relevant condition, behaviour, laboratory value or concomitant medication which, in the opinion of the Investigator, makes the subject unsuitable for entry into the study.
• Subjects who have previously received histone deacetylase inhibitors e.g. vorinostat or have participated in a clinical trial using compound suspected of interfering with protein acetylation status.
• A history of malignancy of any type within 2 years prior to screening. A history of surgically excised nonmelanoma skin cancers is permitted.
• Subjects with a significant history of drug allergy as determined by the Investigator.
• Subjects who have a significant history of alcoholism or drug/chemical abuse as determined by the Investigator.