A Study to Evaluate Sigma-1 and Dopamine-2 Receptor Occupancy by Pridopidine in the Human Brain of Healthy Volunteers and in Patients With Huntington's Disease

Study Overview
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Brief Summary
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The purpose of this study is to demonstrate engagement of pridopidine with S1R and D2R (optional) in the living human brain. No formal statistical analysis will be conducted

Official Title
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A Phase I, Open-Label, Single-Dose, Adaptive (S)-(-)-[18F]Fluspidine and [18F]Fallypride Positron Emission Tomography Study to Evaluate Sigma-1 and Dopamine-2 Receptor Occupancy by Pridopidine in the Human Brain of Healthy Volunteers and in Patients With Huntington's Disease

Conditions
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Health Volunteers, Huntington Disease

Intervention / Treatment
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* Drug: pridopidine (90 mg)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: In general, good physical health as determined by medical history and psychiatric history, suicidality assessment & physical examination Men who are potentially fertile (not surgically [eg, vasectomy] or congenitally sterile Patients with Huntington's disease (HD): diagnosis of HD and with an onset of HD after 18 years of age Additional criteria apply, please contact the investigator for more information Exclusion Criteria: The subject has been previously exposed to ionizing radiation or radioactive substances as a result of clinical research or medical treatment in the past 10 years. The subject has a counterindication to having an MRI History of alcohol, narcotic, or any other substance dependence in the past 2 years Additional Exclusion criteria to patients with Huntington's disease: The patient has a severe motor impairment that might cause artifacts. Patients with a known history of Long QT Syndrome or a first degree relative with this condition. Treatment with any investigational product within 6 weeks of screening or patients planning to participate in another clinical study assessing any investigational product during the study. Additional criteria apply, please contact the investigator for more information

Ages Eligible for Study
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Minimum Age: 25 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: pridopidine<br>Pridopidine (TV-7820) capsules | Drug: pridopidine (90 mg)<br>* single dose will be administered in Cohort 1. Other optional cohorts 2 and 3 may include single dose 0.5 mg, 1 mg, 2.5 mg, 5 mg, 10 mg, 22.5 mg, 45 mg, or 90 mg. The dose will be selected based on the results obtained from Cohorts 1 and 2.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sigma-1 Receptor Occupancy | Receptor occupancy of pridopidine to Sigma-1 receptors (S1R) in the brain was assessed from Positron Emission Tomography (PET) imaging with (S)-(-)-[18F]fluspidine | 2 hours after oral administration of pridopidine | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum Plasma Concentration of Pridopidine | Maximum plasma concentration of pridopidine based on noncompartmental analysis | PK sampling 1 h before pridopidine dosing, and 5, 15, 30, 45, 60 min, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 12, and 24 h after dosing. | 
| Time to Reach Maximum (Peak) Concentration (Tmax) | Multiple PK samples over 24 hours will be calculated for pridopidine and its metabolite TV-45065 in plasma using non-compartmental methods, when possible. | PK sampling 1 h before pridopidine dosing, and 5, 15, 30, 45, 60 min, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 12, and 24 h after dosing. |