MGTX · MeiraGTx Holdings plc

MeiraGTx reported durable efficacy from its Phase 1 AQUAx open-label, dose-escalation trial of AAV-hAQP1, a gene therapy delivered via Stensen’s duct to parotid glands for grade 2/3 radiation-induced xerostomia in cancer-free patients. Improvements in patient-reported Xerostomia Questionnaire (XQ) scores, with 58% unilateral and 75% bilateral participants achieving ≥8-point reductions at 12 months (63% overall ≥10-point), were sustained at 36 months (62% ≥10-point). Average XQ improvements of 13 points (unilateral), 21 points (bilateral), and 17 points overall at 12 months held steady through 3 years. Objective unstimulated whole saliva flow rate (UWSFR) reached normal range levels of 0.36 mL/min at 12 months and 0.34 mL/min at 36 months. Safety data confirmed no serious treatment-related adverse events. The company views AAV-hAQP1 as a potential first-in-class, one-time disease-modifying therapy for persistent RIX affecting 165,000 US and 435,000 global patients annually, supported by market research showing 78% physician preference and 90% projected US market access, driving estimated peak sales of $3.7 billion globally ($2.0 billion US). A webcast was held on April 16, 2026, to discuss these results, highlighting the therapy's transformative potential in a condition lacking effective treatments.