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

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.

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.

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