Huntington disease (HD) is a hereditary neurodegenerative disorder causing impairment in movement, behavioral dysfunction and dementia. The movement disorder is mainly characterized by chorea (involuntary movements) and a progressive loss of voluntary movement causing a substantial functional impairment over time. The study will assess the long-term safety of pridopidine and the treatment effects during long-term, open-label treatment.

Inclusion Criteria:

• Subject is able to, and has provided written Informed Consent prior to any study related procedure.

• Patient has completed the HART (ACR16C009) or the PRIDE-HD (TV7820- CNS-20002) studies and had remained on IMP during the full on-treatment part of the study (including de-escalated patients) or has transitioned from the Open-HART pre-virtualization study period.

• Willing and able to take oral medication and able to comply with the study specific procedures.

• Patient has a wireless internet connection at home (and/or applicable locations) at the first remote visit.

• Patient has the ability to transition from in-person study visits to virtual study visits. The first remote visit (RV1) will take place within approximately 30 days after the last in-person visit.

  • Additional criteria apply, please contact the investigator for more information

Exclusion Criteria:

• Ongoing treatment with tetrabenazine or deutetrabenazine, seizure threshold lowering medications, or certain antipsychotics and antidepressants.

• Newly instigated or changed treatment with neuroleptics/antipsychotics

• Use of tricyclic antidepressants or class I & III antiarrhythmics at any time during the study period.

• Severe intercurrent illness that, in the opinion of the Investigator (or qualified designee), may put the subject at risk when continuing participation in the study.

• Alcohol and/or drug abuse as defined by the Diagnostic and Statistical Manual - Fourth Edition - Text Revision criteria for substance abuse - this includes the illicit use of cannabis.

• Subjects with a known history of epilepsy or a history of febrile seizure(s) or seizure(s) of unknown cause.

• Females who are pregnant or lactating.

• Females who are of child bearing potential and not taking adequate contraceptive precautions (either oral, barrier or chemical contraceptives) are excluded from the trial. Females of child bearing potential taking acceptable contraceptive precautions can be included.

• Known allergy to any ingredients of the trial medication.

  • Additional criteria apply, please contact the investigator for more information

From signing of the informed consent through the end of the follow-up period, which was defined as 30 days after the final study visit in an individual patient, an average of 2.8 years

The study was stopped at Sponsor discretion/request; last patient last visit was 5 Jan 2018.