MeiraGTx Holdings announced positive top-line data from a clinical bridging study of its investigational gene therapy, AAV-GAD, for the treatment of Parkinson’s disease, teeing up a phase 3 trial.
MGT-GAD-025 was a 14-subject, six-month study using AAV-GAD drug product manufactured by MeiraGTx with its commercial platform process. The subjects were randomized to one of three groups — high dose, low dose, and sham (to help reduce bias). Participants had idiopathic Parkinson's disease, a history of levodopa responsiveness for at least 12 months, and a Unified Parkinson’s Disease Rating Scale(UPDR) Part 3 score of ≥25 points in the "off" state.
At week 26, a statistically significant 18-point average improvement from baseline in UPDRS Part 3 “off” medication score was demonstrated in the high dose group, with no significant change in the sham or low dose groups. Additionally, at 26 weeks, significant improvements from baseline in the patient-reported quality of life score — Parkinson’s Disease Questionnaire (PDQ-39) — were demonstrated in both the high and low dose groups with no significant change in the sham group.
“The significant, substantial, and clinically meaningful changes observed in this small, sham-controlled study provide us with a clear path forward in our clinical development strategy and underpin our discussions with regulators in the U.S., Europe and Japan with the goal of initiating a phase 3 study to support approval of this disease-modifying treatment globally,” said Alexandria Forbes, Ph.D., president and chief executive officer of MeiraGTx.
AAV-GAD is an investigational gene therapy designed to reprogram the dysfunctional movement-controlling brain circuits associated with Parkinson’s through the local production of GABA, a chemical neurotransmitter that can help restore more normal activity to these critical cells in any form of Parkinson’s disease. AAV-GAD is delivered via a one-time infusion through a minimally invasive procedure, using a MeiraGTx proprietary device that allows infusion of the equivalent of one drop of gene therapy solution into the subthalamic nucleus, a key regulator of the circuits responsible for normal movement.