The purpose of this study is to evaluate the clinical safety and effectiveness of Visco-ease dry mouth spray for the treatment of Radiotherapy Induced Xerostomia (RIX) in head and neck cancer patients.

A parallel group double blind study design has been selected. The primary outcome is change in GRIX scores from baseline (visit 1) to end of treatment (visit 7). The primary outcome will be compared between Visco-ease and the placebo treatment.

Inclusion Criteria:

1. Subject has provided written informed consent
2. Male or female subjects ≥ 18 years of age
3. Subjects prescribed radiotherapy or chemoradiotherapy as primary treatment for head and neck tumours where one or more parotid glands will receive a significant dose of radiation as judged by the CI or PI during the radiotherapy planning process

Exclusion Criteria:

1. Subject is pregnant or breastfeeding
2. Subjects with known allergies to egg, soya, or lanolin (sheep's wool grease) based products
3. Subjects with a history of an autoimmune disease with pre-treatment xerostomia (e.g. Sjögren's syndrome) or other underlying systemic illness known to cause xerostomia independent of prior radiation therapy exposure
4. Subjects who have participated in an investigational medicinal product study within 30 days prior to signing consent
5. Any clinically significant disease or condition that may interfere with the study treatment or outcome of the study (at the discretion of the CI or PI)
6. Subjects who are unable to independently complete the questionnaire or diary
7. Subjects who are judged inappropriate for inclusion in the study by the CI or PI
8. Subjects with head and neck cancer who have had surgery to the primary site. Neck dissection alone is not an exclusion