MeiraGTx Unveils Positive Three-Year Data from Phase 1 AQUAx Study of AAV-hAQP1 for Radiation-Induced Xerostomia

MeiraGTx Holdings plc (NASDAQ: MGTX), a clinical-stage genetic medicines company, has announced highly positive three-year data from its completed Phase 1 AQUAx clinical study evaluating AAV-hAQP1 gene therapy for the treatment of grade 2/3 late radiation-induced xerostomia (RIX), a severe and debilitating condition with no current effective treatment options.

Key Highlights from the Report

• Sustained Clinical Benefits: Patients in both bilateral and unilateral cohorts who received a one-time administration of AAV-hAQP1 maintained clinically meaningful improvements in xerostomia symptoms at the three-year mark, as measured by the Patient-Reported Outcome (PRO) Xerostomia Questionnaire.
• Objective Saliva Flow Improvement: Increases in Unstimulated Whole Saliva Flow Rate (UWSFR), a direct measure of the therapy’s mechanism of action, were also sustained for three years post-treatment.
• Safety Profile: AAV-hAQP1 demonstrated a strong safety and tolerability profile with no significant adverse events reported at any dose level over the three-year period.
• Durability and Consistency: The data not only reveal durable population-level benefits, but also show highly consistent responses at the individual patient level, reinforcing the potential of AAV-hAQP1 as a disease-modifying, one-time therapy.
• Large Market Opportunity: The condition addressed—radiation-induced xerostomia—affects a large, well-defined patient population, typically head and neck cancer survivors, for whom current therapeutic options are extremely limited.
• Next Steps: The company is hosting a webcast to discuss these results and the future of the program, signaling advancing development and potential commercial readiness.

Details Shareholders Need to Know

• Potential Share Price Impact: The three-year durability and safety of AAV-hAQP1, following a single in-office administration, sets a new benchmark for the treatment of RIX and could position MeiraGTx as a leader in this high-need therapeutic area. This is a significant inflection point, as the therapy is now being regarded by clinicians as a simple, one-time, disease-modifying intervention.
• Commercial Opportunity: With persistent radiation-induced xerostomia being a severe unmet need and the therapy offering a straightforward procedure, there is strong physician enthusiasm, which could translate to rapid market uptake if regulatory approvals are secured.
• Regulatory and Development Path: The company continues to monitor patients for five years post-treatment, with safety as the primary endpoint and efficacy as a major focus. The durability of the effect increases the likelihood of regulatory support and could accelerate commercialization.
• Pipeline and Platform Strength: Beyond AAV-hAQP1, MeiraGTx boasts a broad pipeline of late-stage clinical programs and proprietary manufacturing capabilities. Their in-house production and novel riboswitch gene regulation technology for oral small molecule control add further competitive advantages.
• Risks and Forward-Looking Statements: Investors should be aware of the usual risks associated with clinical-stage biotechs, including regulatory, development, and commercialization uncertainties, as well as the forward-looking nature of the company’s projections. Full risk factors are detailed in the company’s latest SEC filings.

About the Phase 1 AQUAx Clinical Trial

The AQUAx trial was designed as an open-label, non-randomized, dose-escalation study to evaluate the safety and preliminary efficacy of AAV-hAQP1, administered via Stensen’s duct to one or both parotid glands in patients with grade 2 or 3 radiation-induced xerostomia. Eligible patients were cancer-free for at least five years (or two years if HPV-positive) following radiation for head and neck cancer. The primary endpoint was safety, with efficacy assessed by patient-reported symptoms and changes in salivary output.

About MeiraGTx

MeiraGTx is a vertically integrated genetic medicines company with a robust clinical pipeline targeting both rare and more common diseases, including programs in ophthalmology, Parkinson’s disease, and now, radiation-induced xerostomia. The company controls end-to-end manufacturing, including GMP-licensed facilities, and is developing a transformative riboswitch gene regulation platform for precise in vivo control of gene expression by oral small molecules. This positions MeiraGTx uniquely for efficient development and commercialization of gene therapies in large, underserved disease areas.

Webcast Details

The company will host a webcast on Thursday, April 16, 2026, at 8:00 a.m. ET to further discuss the results and answer investor questions. Registration and replay information are available on the MeiraGTx investor website.

Investor and Media Contacts

Investors: [email protected]
Media: Jordyn Temperato, LifeSci Communications, [email protected]

Disclaimer: This article is for informational purposes only and does not constitute investment advice. Investors should consult the company’s official filings and speak to a qualified financial advisor before making any investment decisions. Past performance is not indicative of future results. All forward-looking statements are subject to risks and uncertainties as detailed in MeiraGTx’s latest SEC filings.

View MeiraGTx Holdings plc Historical chart here