April 16, 2026-
MeiraGTx Holdings plc has reported positive three-year data from its completed Phase 1 AQUAx clinical trial evaluating AAV-hAQP1 for the treatment of grade 2/3 late radiation-induced xerostomia (RIX), demonstrating sustained clinical benefit following a single administration.
The long-term follow-up data show that clinically meaningful improvements in xerostomia symptoms, as measured by the patient-reported Xerostomia Questionnaire (XQ), were maintained through 36 months post-treatment. These findings were consistent across both bilateral and unilateral treatment cohorts, highlighting durability at both the population and individual patient levels.
In parallel with patient-reported outcomes, objective measures of salivary function also remained improved over time. Increases in unstimulated whole saliva flow rate (UWSFR), a key biomarker reflecting salivary gland function and the therapy’s mechanism of action, were sustained throughout the three-year follow-up period.
AAV-hAQP1 continued to demonstrate a favorable safety and tolerability profile across all dose levels evaluated in the study, with no new safety signals identified. The therapy is administered as a one-time procedure via Stensen’s duct to the parotid glands, offering a minimally invasive approach for a condition that currently lacks effective treatment options.
Radiation-induced xerostomia is a common and debilitating long-term complication in patients treated for head and neck cancers, often significantly impacting quality of life. The durability of both subjective and objective improvements observed in the AQUAx study suggests that AAV-hAQP1 may have disease-modifying potential in this setting.
Patients enrolled in the Phase 1 AQUAx trial are being followed for up to five years to further assess long-term safety and efficacy. The company presented the full three-year dataset, including cohort-level and individual patient outcomes, during a webcast held on April 16, 2026.
