Modulation of GABA-A Receptors in Parkinson Disease-Transdermal Flumazenil Arm (GABA-A)

December 15, 2022 updated by: Nicolaas Bohnen, MD, PhD

Modulation of GABA-A Receptors and Axial Motor Impairments in Parkinson

The arm of this study evaluates possible GABA-A receptor target engagement effects of the FDA-approved medication, transdermal flumazenil (added 4/2020, replaced clarithromycin), in the setting of Parkinson's disease. Half of the subjects will receive transdermal flumazenil for 7-10 days, and half will receive a placebo. [11C]Flumazenil GABA-A receptor PET imaging will be used to assess target engagement effects. Note [11C]Flumazenil GABA-A receptor PET was not performed as part of the transdermal flumazenil study because of a Covid pandemic research amendment.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study focuses on neurochemical changes in the brain that occur in Parkinson's disease. In particular we will be looking a neurotransmitter called GABA. In some Parkinson's disease patients we see too much GABA activity in the brain. This target engagement study examines the target engagement effect of GABA-A receptor modulation by transdermal flumazenil (previously clarithromycin). [11C]-flumazenil Positron Emission Tomography (PET) imaging results will be used to assess for possible GABA-A receptor target engagement effects of transdermal flumazenil (previously clarithromycin). Note [11C]Flumazenil GABA-A receptor PET was not performed as part of the transdermal flumazenil study because of a Covid pandemic research amendment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
34

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48106
        • University of Michigan Health System Functional Neuroimaging, Cognitive and Mobility Laboratory

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

50 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Parkinson's disease (PD): PD diagnosis will follow the UK Parkinson's Disease Society Brain Bank Research Center (UKPDSBRC) clinical diagnostic criteria for PD.
  2. Hoehn and Yahr stages 2-4
  3. Absence of dementia confirmed by cognitive testing.
  4. Abnormal 11C-Dihydrotetrabenazine ([11c]-DTBZ) PET study to demonstrate nigrostriatal dopaminergic denervation

Exclusion Criteria:

  1. PD with Dementia (PDD) or dementia with Lewy bodies (DLB).
  2. Other disorders which may resemble PD, such as vascu¬lar dementia, normal pressure hydrocephalus, multiple system atrophy, corticobasal ganglionic dege¬neration, or toxic causes of parkinsonism. Prototypical cases have distincti¬ve clinical profiles, like early and severe dysautonomia or appendicular apraxia, which may differentiate them from idiopathic PD. The use of the UKPDSBRC clinical diagnostic criteria for PD will mitigate the inclusion of subjects with atypical parkinsonism.
  3. Subjects currently on benzodiazepine, GABAB-ergic medications (baclofen, tizanidine), modafinil, neuroleptic, anticholinergic (trihexyphenidyl, benztropine), or cholinesterase inhibitor drugs.
  4. Evidence of a mass lesion on structural brain imaging (MRI).
  5. Participants in whom MRI is contraindicated including, but not limited to, those with a pacemaker, presence of metallic fragments near the eyes or spinal cord, chest, or cochlear implant.
  6. Severe claustrophobia precluding MR or PET imaging.
  7. Subjects limited by participation in research procedures involving ionizing radiation.
  8. Pregnancy (urine or serum pregnancy test within 48 hours of each PET session) or breastfeeding.
  9. History of seizures
  10. Significant anxiety or history of panic disorder.
  11. History of recent suicide attempt or overdose of tricyclic antidepressants or other medications.
  12. History of transient ischemic attack (TIA) or stroke within the last year.
  13. History of systemic lupus erythematosis.
  14. Abnormal liver enzymes (AST or ALT) > 3 times upper limit of normal.
  15. History of atrial fibrillation.
  16. History of retinal branch artery occlusion.
  17. Active dermatitis inner forearms.
  18. Any other medical history determined by investigators to preclude safe participation.

Additional Exclusion Criteria for Flumazenil sub-studies:

  1. Allergy to flumazenil
  2. Significant liver disease
  3. History of alcohol or other substance abuse within past two years.
  4. Subjects currently taking benzodiazepines

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Clarithromycin (Not used anymore as of 4/2020; study aborted)
Clarithromycin 250mg (1 capsule) will be taken orally twice a day for 3 days and if tolerated will be increased to 500mg (2 capsules) orally twice a day for 4-6 days.
Drug: Clarithromycin (Not used as of 4/2020)
Clarithromycin (generic) capsule 250mg each
Other Names:
  • Biaxin
Placebo Comparator: Placebo (Not used anymore as of 4/2020; study aborted)
Placebo will be taken exactly as the clarithromycin arm: 1 capsule orally twice a day for 3 days and if tolerated will be increased to 2 capsules orally twice a day for 4-6 days.
Drug: Placebo (Not used as of 4/2020)
Lactose in a gel capsule
Active Comparator: Transdermal flumazenil (added 4/2020 as safer alternative for clarithromycin)
Added in April 2020. Subjects will take 18mg transdermal application every 3-4 hrs dispensed as 3 dispenser bottle clicks of 0.25 ml each, while awake for 3 days then if no side-effects subjects will increase to 36mg transdermal application every 3-4 hrs dispensed as 6 dispenser bottle clicks of 0.25 ml each, while awake.
Drug: Transdermal flumazenil (Added 4/2020)
Transdermal flumazenil 24mg/mL
Placebo Comparator: Placebo cream (added 4/2020)
Added in April 2020. Placebo will be taken exactly as the transdermal flumazenil arm: Subjects will take 18mg transdermal application every 3-4 hrs dispensed as 3 dispenser bottle clicks of 0.25 ml each, while awake for 3 days then if no side-effects subjects will increase to 36mg transdermal application every 3-4 hrs dispensed as 6 dispenser bottle clicks of 0.25 ml each, while awake.
Drug: Placebo (Added 4/2020)
Transdermal placebo
Other Names:
  • Placebo cream

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Quantitative Biomechanics 1 (Clinical Motor Ratings MDS-UPDRS)
Time Frame: Day 1 (before treatment administration), day 7 (after 7 days of treatment), and day 14 (7 days of treatment discontinuation).
We will use the total Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III - motor scale rating scores to assess motor function. Scale from 0-132, higher scores indicate worse motor outcomes. Outcome measure was collected during dopaminergic medication ON state.
Day 1 (before treatment administration), day 7 (after 7 days of treatment), and day 14 (7 days of treatment discontinuation).

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Quantitative Biomechanics 2 (MiniBESTest Dynamic Balance Scale Sensory Subscore)
Time Frame: Day 1 (before treatment administration), day 7 (after 7 days of treatment), and day 14 (7 days of treatment discontinuation).
MiniBEST sensory subscore measures an individual's ability to maintain balance under conditions of sensory constrain and unstable/inclined standing surface. It is is computed as a sum of MiniBEST items 7, 8, and 9.The score ranges from 0 to 6, with 0 indicating inability to balance under all of the condition, and 6 indicating no difficulty in maintaining balance under any of the conditions (lower score indicates worse balance). Outcome measure was collected during dopaminergic medication ON state.
Day 1 (before treatment administration), day 7 (after 7 days of treatment), and day 14 (7 days of treatment discontinuation).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Nicolaas Bohnen, MD, PhD

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Neurological Disorders and Stroke (NINDS)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Nicolaas I Bohnen, MD, PhD, University of Michigan

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 29, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 8, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 8, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 26, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 13, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 20, 2018

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 10, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 15, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HUM00360361-A
  • R01NS099535 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Conditions

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