Protocol: carrageenan for the prevention of oral HPV infection – a feasibility randomised clinical trial

INTRODUCTION: Head and neck cancers (HNCs) are a significant health burden worldwide. Oral human papillomavirus (HPV) infection is a major risk factor for HNCs. Unfortunately, currently available prophylactic vaccines have limited coverage and potential for HPV type replacement. Carrageenan, a natural product extracted from marine red algae, has demonstrated potency as an HPV inhibitor and could offer a potential alternative to prevent HPV-related diseases, including oral HPV infection. However, there is a lack of clinical studies on the effect of carrageenan on oral HPV infections. As a first step to address this gap, we propose a randomised controlled trial (RCT) to evaluate the feasibility of conducting a larger multicentric RCT to investigate the effect of a carrageenan mouthwash on oral HPV infection. METHODS AND ANALYSIS: We will conduct a placebo-controlled triple-blinded feasibility RCT with two parallel arms, each arm consisting of 20 participants. Participants will complete a single in-person visit at baseline and conduct biweekly follow-ups from home by completing a web-based questionnaire and sending saliva self-samples via mail. During the 6-month period trial, participants will gargle with the mouthwash morning and night, and around sexual activities. The study will evaluate several factors including recruitment and retention rates, the feasibility of data collection procedures, compliance with study procedures, acceptability of RCT procedures and intervention and safety data on carrageenan use in the oral cavity. We will estimate the standard deviation of outcome measures, including time to the incidence of oral HPV infection and time to clearance of prevalent oral HPV infection. The trial primary outcome is whether to proceed to a definitive trial based on prespecified progression criteria. ETHICS AND DISSEMINATION: The protocol was approved by the McGill University institutional review board. Study results will be presented at scientific conferences and published in academic journals. TRIAL REGISTRATION NUMBER: NCT05746988.