A Double-blind Study to Evaluate the Safety of Glutamic Acid Decarboxylase Gene Transfer in Parkinson's Participants

September 2, 2025 updated by: MeiraGTx, LLC

A Randomized, Double-Blind, Sham-Controlled Study to Evaluate the Safety and Tolerability of Glutamic Acid Decarboxylase Gene Transfer to the Subthalamic Nuclei in Participants With Parkinson's Disease

The objective of this clinical trial was to evaluate the safety and tolerability of adeno-associated virus (AAV)-mediated delivery of glutamic acid decarboxylase (GAD) gene transfer into the subthalamic nuclei (STN) of participants with Parkinson's Disease.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The planned length of participation in the study for each participant was approximately 7 months, including a screening period of up to 40 days, randomization, surgery, and a follow-up period of 26 weeks.

Study Type

Interventional

Enrollment (Actual)

14

Phase

  • 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
    • Connecticut
      • New Haven, Connecticut, United States, 06510
        • Yale University - Yale New Haven Hospital
    • Michigan
      • West Bloomfield, Michigan, United States, 48322
        • Henry Ford West Bloomfield Hospital
    • New York
      • New York, New York, United States, 10032
        • Columbia University Irving Medical Center
      • New York, New York, United States, 10021
        • Weill Cornell Medicine
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19107
        • Thomas Jefferson University
    • West Virginia
      • Morgantown, West Virginia, United States, 26506
        • West Virginia University

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

Ages Eligible for Study

25 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Confirmed Parkinson's Disease
  • Levodopa responsiveness for at least 12 months
  • UPDRS Part 3 score of ≥25 points in the "off" state

Exclusion Criteria:

  • History of brain surgery to treat Parkinson's Disease
  • Any history of cerebral insult or central nervous system infection
  • Atypical Parkinson's Disease
  • Focal or lateralized neurologic deficits
  • Evidence of significant medical or psychiatric disorders
  • Cognitive impairment as defined by the Montreal Cognitive Assessment (MoCA) ≤ 20
  • Beck Depression Inventory-II score of ≥ 20

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: AAV-GAD Low Dose
Eligible participants received bilateral infusion of AAV-GAD low dose into the STN
Genetic: AAV-GAD Low Dose
Bilateral infusion of AAV-GAD low dose
Experimental: AAV-GAD High Dose
Eligible participants received bilateral infusion of AAV-GAD high dose into the STN
Genetic: AAV-GAD High Dose
Bilateral infusion of AAV-GAD high dose
Sham Comparator: Sham Surgery
Eligible participants underwent a sham surgical procedure
Procedure: Sham Surgery
Sham infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Adverse Events Related to the Treatment
Time Frame: Baseline to Week 26
The primary outcome measure is the safety of treatment with AAV-GAD, assessed by the absence of IMP-related treatment-emergent adverse events.
Baseline to Week 26
Incidence of Serious Adverse Events Related to the Treatment
Time Frame: Baseline to Week 26
The primary outcome measure is the safety of treatment with AAV-GAD, assessed by the absence of IMP-related serious treatment-emergent adverse events.
Baseline to Week 26

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
The effect of AAV-GAD on the Unified Parkinson's Disease Study Rating Scale (MDS-UPDRS) Part 3 (motor function) score in the "off medication state"
Time Frame: Baseline to Week 26
mean change from baseline to Weeks 12 and 26 for the AAV-GAD groups compared to the sham group in MDS-UPDRS Part 3 (motor examination) score in the "off" state.
Baseline to Week 26

Collaborators and Investigators

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

Sponsor

MeiraGTx, LLC

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)

October 5, 2022

Primary Completion (Actual)

September 6, 2024

Study Completion (Actual)

September 6, 2024

Study Registration Dates

First Submitted

October 12, 2022

First Submitted That Met QC Criteria

October 28, 2022

First Posted (Actual)

November 2, 2022

Study Record Updates

Last Update Posted (Estimated)

September 5, 2025

Last Update Submitted That Met QC Criteria

September 2, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MGT-GAD-025

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

Yes

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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