A Study Evaluating if Pridopidine is Safe, Efficacious, and Tolerable in Patients With Huntington's Disease

Inclusion Criteria:

- Pride HD completion within the last 6 months, including 2 week follow up period or
patients who transitioned from the Open HART study or patients who complete future
safety and efficacy clinical trials of pridopidine. In addition, patients who have
already completed their defined study period under Open PRIDE HD global or local
amendments and have discontinued treatment with pridopidine will be allowed to re
enter the Open PRIDE HD study.

- Women of child bearing potential or male participants: Adequate contraception and
birth control

- Good general health

- other criteria apply, please contact the investigator for more information

Exclusion Criteria:

- Similar baseline criteria for ECG, vital signs, cardiovascular system, and renal
function to PRIDE HD;

- Similar concomitant medication restrictions to PRIDE HD.

- other criteria apply, please contact the investigator for more information