A Open-label Food Effect Study With SEN0014196 in Subjects With Huntington Disease

In addition to the pharmacokinetic endpoints, the study will assess the safety and
tolerability of 100 mg once daily (qd) doses of SEN0014196 over 14 days in subjects with HD
and explore potential biomarkers for use in subsequent Phase 2/3 studies.

Inclusion Criteria:

- Subjects with early to mid HD, i.e., genetically confirmed HD (cytosine, adenine,
guanine [CAG] codon repeat length ≥ 36), motor signs of HD, and a Total Functional
Capacity Subscale Score (TFC) ≥ 7

- Body mass index between 18 and 31 kg/m2 inclusive

- All subjects must have a body weight greater than 50 kg

- Female subjects must be surgically sterile, postmenopausal, or willing to practice a
highly effective method of contraception. All female participants must be
nonlactating and nonpregnant. Male subjects must agree to use a reliable method of
birth control during the study and for 3 months after the last dose of study drug.

- Capable of providing informed consent

- MMSE ≥24

- Subjects must have a live-in competent observer

Exclusion Criteria:

- Participation in a study or received an investigational drug within 30 days of the
Baseline Visit

- Any prior or concomitant use of compounds suspected of interfering with protein
acetylation

- Any concomitant use of medications that are known inhibitors of CYP450 enzymes or
substrates of CYP1A2 at the time of enrollment

- Suicide risk, as determined by meeting either of the following criteria: a) a suicide
attempt within the past year or suicidal ideation within 60 days of the Screening
Visit; b) Significant risk of suicide, as judged by the Investigator

- Subjects with MMSE < 24

- Subjects with presence of clinically significant psychosis and/or confusional states,
in the opinion of the Investigator

- Subjects with clinically significant laboratory or ECG abnormalities at Screening or
Baseline

- Subjects with clinically relevant hematologic, hepatic, cardiac, or renal disease

- Subjects with a current or past (within the last 12 months) history of epilepsy or
seizures

- A medical history of infection with human immunodeficiency virus, hepatitis C, and/or
hepatitis B

- Subjects with a history of substance abuse within the past 12 months

- Female subjects who are pregnant or breastfeeding

- Known allergy to any ingredient in the study drug

- A history of malignancy of any type within 2 years prior to Screening. A history of
surgically-excised nonmelanoma skin cancers is permitted.

- Any relevant condition, behavior, laboratory value, or concomitant medication which,
in the opinion of the Investigator, makes the subject unsuitable for entry into the
study