MeiraGTx Announces Positive Clinical Data from the AQUAx Phase 1 Clinical Study of AAV2-hAQP1 for the Treatment of Grade 2/3 Radiation-Induced Xerostomia - Seite 2

Dr. Forbes continued, “We are excited to present these data showing meaningful activity across key endpoints in participants with intractable grade 2 and 3 xerostomia which has been persistent for many years prior to treatment with AAV2-hAQP1. We have initiated a randomized, double-blind, placebo-controlled, Phase 2 study which is currently enrolling and treating participants, and we look forward to advancing the development of a potential treatment for this severely debilitating condition.”

Full data from the AQUAx Phase 1 study is expected to be reported at a scientific meeting in the second half of 2023.

Phase 1 AQUAx Trial of AAV2-hAPQ1 for the Treatment of Grade 2/3 Radiation-Induced Xerostomia

AQUAx is an open label, multi-center, dose escalation study of a single administration of AAV2-hAQP1 to one or both parotid glands in participants with radiation-induced salivary hypofunction and grade 2/3 xerostomia. There were 4 escalating dose cohorts with 3 participants per cohort for both unilaterallly and bilaterally treated participants. All participants were followed for 1-year post-treatment in the Phase 1 AQUAx study and were then enrolled in a long-term follow-up study for a total of 5 years. The primary endpoint was safety and the secondary endpoints included change from baseline to 12 months in patient-reported measures of xerostomia symptoms using the Global Rate of Change Questionnaire, or GRCQ, and the Xerostomia Questionnaire, or XQ. In addition, whole saliva flow rate was assessed. The study was conducted at 4 centers, with 3 in the US and 1 in Canada.

Treatment appears safe and well tolerated at each dose tested with no dose-limiting toxicity or treatment-related serious adverse events.

Efficacy Data presented from the 24 participants treated in the AQUAx study

• Improvements observed in both of the patient reported assessments of xerostomia symptoms, Global Rate of Change Questionnaire (GRCQ) and Xerostomia Questionnaire (XQ), in both unilateral and bilateral treated cohorts at 12 months post-treatment
• Improvements in salivary flow were seen in unilateral as well as bilateral cohorts
• Early long-term follow-up data suggest durability of improvement out to at least 3 years post-treatment
  

McMaster Global Rate of Change Questionnaire (GRCQ):

Bilateral Cohorts (n=12) to 12 Months

• 10/12 (83%) participants at 12 months reported symptoms of dry mouth as ”better” following treatment 
• Each of these 10 participants rated changes in xerostomia scores that were “important” or “very important” with a score of 2 or more at 12 months
• 5 participants rated the change in xerostomia symptoms with the highest improvement scores of 6 or 7 denoting a “very important improvement”
• No participant reported worsening of xerostomia symptoms

Unilateral Cohorts (n=12) to 12 Months