A Study of AAV2-hAQP1 Gene Therapy in Participants With Radiation-Induced Late Xerostomia

Inclusion Criteria: * Completed beam radiation therapy for head and neck cancer at least 3 years prior to the first screening visit * No history of recurrent head and neck cancer, parotid gland cancer, or a second primary cancer, except for treated basal cell or squamous cell carcinoma of the skin or in situ cervical carcinoma * An unstimulated whole saliva flow rate (mL/min) \>0 (i.e., at least one drop of saliva in the collection tube) * A stimulated whole saliva flow rate (mL/min) within a specified range after mechanical stimulation by chewing * Average screening XQ Total Score at or above a specified threshold * No evidence of head and neck cancer, defined as a negative otolaryngology exam and a negative computed tomography (CT) scan of the head, neck, and chest with contrast. If a participant has had a magnetic resonance imaging (MRI) study, CT scan, positron emission tomography (PET), or fluorodeoxyglucose-positron emission tomography (FDG-PET) scan of the head, neck, and chest within 6 months of signing the informed consent form (and at least 3 years after the completion of radiotherapy), then that scan may be used for eligibility determination and a CT scan at screening will not be required. If the CT of the neck captures images from the forehead down to the neck, no CT of the head is required. * Either received treatment with one or more prescription sialagogues and elected to discontinue therapy or, in consultation with their physician, elected not to initiate suc…