MeiraGTx Holdings’ MGTX clinical bridging study of its gene therapy candidate, AAV-GAD, for treating Parkinson’s disease (PD) met its primary study objective of safety and tolerability. The stock soared 14.9% in response to the news.

MGTX’s PD Gene Therapy Candidate Betters Sham Treatment

The MGT-GAD-025 study of AAV-GAD for PD demonstrated significant and clinically meaningful improvements from baseline for key efficacy endpoints after 26 weeks of treatment.

Per the data readout, treatment with the candidate resulted in a statistically significant 18-point average improvement from baseline in the UPDRS Part 3 (motor examination) “off” medication score in the high-dose group at week 26. However, no significant change in the sham or low-dose groups was observed.

Additionally, MeiraGTx reported significant dose-dependent improvements from baseline in the disease-specific, patient-reported quality of life PDQ-39 score in both the high and low-dose groups with no significant change in the sham group at 26 weeks.

Year to date, shares of MeiraGTx have plunged 24.1% compared with the industry’s 1.8% decline.

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The investigational gene therapy was also found to be generally safe and overall well-tolerated. No serious, AAV-GAD treatment-related adverse events were observed.

Per MGTX, PD is the second most common neurodegenerative disorder after Alzheimer’s, affecting nearly one million people in the United States, with around 90,000 new cases diagnosed annually. Globally, more than 10 million people are living with PD. Initially, most patients respond well to dopamine replacement therapy, but over time, its effectiveness often diminishes and adverse side effects may arise, significantly impacting quality of life and daily functioning. This represents a high unmet medical need.

While the cause of PD remains unknown for most, a small percentage have a genetic basis. In all cases, PD involves disruptions in movement control circuits.

AAV-GAD has a novel mechanism of action that aims to correct the aberrant circuitry that results from the depletion of dopamine in the brain of idiopathic PD patients as the disease progresses. Using the company's proprietary delivery instrument, AAV-GAD is administered as a one-time infusion into the subthalamic nucleus, a key regulator of the circuits responsible for normal movement.

MGTX’s Path Forward for AAV-GAD Following Upbeat Results

Based on the encouraging data readout from the MGT-GAD-025 study, MeiraGTx is currently gearing up to discuss these results with regulatory bodies in the United States, EU and Japan to potentially initiate a phase III study that will support the approval of this disease-modifying treatment globally.