This study evaluates the tolerability, safety and activity of SRX246 in the treatment of
irritability in patients with Huntington's disease. Two-thirds of all participants will
receive SRX246, while the other third will receive a placebo.
1. Male and female Subjects aged 18 years or older
2. Subjects must have clinical features of HD, which can include motor, cognitive, or
3. A confirmatory family history of HD; OR CAG repeat expansion ≥ 37
4. Total Functional Capacity (TFC) score of 5-13
5. Evidence of irritability; a score of at least 2 or greater on the severity measure of
either the UHDRS Irritability question (30b) or Aggression question (Disruptive or
Aggressive Behavior, 31b)
6. Women of childbearing potential (i.e., those not postmenopausal or surgically
sterile) must have a negative pregnancy test, be non-lactating and use adequate
contraception methods during the study. Adequate birth control includes: abstinence;
oral, implanted or injected contraceptives, e.g., birth control pills; intra-uterine
device; barrier (vaginal ring or diaphragm/cervical cap with spermicide); transdermal
patch. Reliable contraception must have been in use 30 days prior to the Baseline
Visit. Partner(s) contraception (e.g., male partner with vasectomy or other surgical
contraception) is acceptable.
7. Men must agree not to father a child during the study and one month after and to use
contraception. Barrier with spermicide or surgical contraception is acceptable.
Partner(s) contraception (e.g., female partner taking birth control pills or
surgically sterile) is acceptable.
8. Subjects must be able to swallow study drug capsules whole.
9. Sufficient English skills to complete all assessments without assistance of an
English language interpreter. Subjects with HD who cannot read or write might qualify
for enrollment in the study. Site PIs will have to decide in each case whether the
Subject can understand and fully participate with help from his/her Informant.
10. Availability of a responsible Informant (referred to as a "study partner" in the
consent document) who has good English skills, is familiar with the Subject, and is
able and willing to comply with all required study procedures, ensuring that the
patient attends all study visits and takes the study medicine as instructed. The
study partner must spend time with the patient a minimum of 4 times per week on 4
separate days, and must monitor the patient's compliance and adverse events,
participate in caregiver assessments, and use the eDiary.
11. Subject has provided written, informed consent or, if Subject lacks the capacity to
provide informed consent (as determined by an independent assessment by a qualified
healthcare provider not directly involved in other study activities), a legally
authorized representative (LAR) has provided written informed consent and the Subject
has provided assent.
1. Any significant neurologic disease other than HD at Screening.
2. Severe psychotic features or other severe psychiatric symptoms within the last three
months which could lead to difficulty complying with the protocol.
3. History of active alcohol or substance abuse within the past two years or Subject is
unable to refrain from substance abuse throughout the study.
4. Any chronic disability, significant systemic illness or unstable medical condition at
Screening or Baseline that could lead to difficulty complying with the protocol.
5. Use of any investigational drugs within 30 days of Screening.
6. Subject has known allergy to any of the components of study medication.
7. Subject is currently pregnant, breast-feeding and/or lactating.
8. Subject acknowledges present use of illicit drugs at Screening.