Positive trial for Neurologix gene therapy in Parkinson’s

The 12-patient trial is the world’s first study to use a viral vector for the treatment of an adult neurological disease. The vector was injected into a specific target site in the brain in order to transfer a gene to treat Parkinson’s disease. The gene encodes glutamic acid decarboxylase (GAD), an enzyme which synthesizes the major inhibitory neurotransmitter in the brain, (gamma)-aminobutyric acid (GABA).

According to the interim findings from the trial, Neurologix’s treatment appears to be safe and well-tolerated in advanced Parkinson’s disease, with no evidence of adverse effects or immunologic reaction related to the study treatment.

Patients in the trial, at one year, exhibited a statistically significant improvement (27%) in motor function on the side of their body correlating to the treated part of the brain, as measured by the Unified Parkinson Disease Rating Scale (UPDRS).

In contrast, the untreated side evidenced no significant improvement in the UPDRS score. Also, activities of daily living (ADL), another standard measure of Parkinson’s severity which is recorded by the patients themselves, showed a strong trend toward statistical improvement.

Under the FDA-sanctioned trial protocol, patients with advanced Parkinson’s disease received unilateral (one side of the brain) infusion of AAV-GAD via a hair-thin catheter into the subthalamic nucleus (STN), a deep brain structure known to function abnormally in Parkinson’s patients.

“While the primary objective of any phase I trial is to demonstrate safety, the FDA’s requirement of unilateral infusion of AAV-GAD allowed us the unique opportunity to compare treated and untreated sides of the brain,” commented Drs Kaplitt and During, co-founders of Neurologix and consultants to the company. “In essence, the untreated side acted as a control. The combined clinical and imaging data provide powerful evidence that this treatment appears to be efficacious, as well as safe, at the current dose levels.”