Gene Therapy AAV-GAD Shows Potential in Treating Parkinson’s Symptoms

A new experimental gene therapy called AAV-GAD has shown promising results in improving motor symptoms and quality of life for many people with Parkinson’s disease in an early trial, according to the company MeiraGTx. Alexandria Forbes, the CEO of MeiraGTx, expressed excitement about the positive results from the study. AAV-GAD works by delivering a modified virus directly into a part of the brain called the subthalamic nucleus, which is important for movement and is affected by Parkinson’s. The therapy introduces the GAD gene, which helps produce a molecule called GABA, crucial for regulating brain activity. By boosting GABA levels, the therapy aims to improve brain signaling and ease Parkinson's symptoms, which are often caused by low dopamine levels. The clinical trial involved 14 participants with Parkinson’s that had no known cause. At the start, all patients had moderate motor symptoms. Some received low or high doses of AAV-GAD, while others had a sham (fake) procedure. Over about six months, the study primarily focused on safety, and there were no major safety concerns reported. Results showed that those in the high-dose group had significant improvements in their motor symptoms, scoring 18 points better on a standardized assessment. In contrast, those in the low-dose and sham groups showed little to no change. Forbes highlighted that even a 5 to 10 point improvement is meaningful, making the high-dose results especially noteworthy. Participants also reported better quality of life, with significant score improvements on a questionnaire designed for Parkinson's patients. In the high-dose group, everyone improved, while a smaller percentage improved in the low-dose group, and the sham group actually showed a slight decline. The AAV-GAD used in this trial was produced by MeiraGTx, and they plan to use the same process if the therapy gets approved for general use. Participants who completed this trial can continue to receive the treatment in a follow-up study for up to five years. MeiraGTx is also preparing for a larger Phase 3 trial to further evaluate the therapy and support its approval worldwide. Forbes emphasized that the significant changes seen in this small study help guide the future development of this potential treatment.