A Trial to Compare Antibacterial vs. Placebo Mouthwash to Reduce the Incidence of Sexually Transmitted Infections (STIs) in Men Who Have Sex With Men (MSM) Taking HIV Pre-Exposure Prophylaxis (PrEP) (PReGo)

A Double-blind Single Center, Crossover, Randomized Controlled Trial of Antibacterial vs. Placebo Mouthwash to Reduce the Incidence of Gonorrhea/Chlamydia/Syphilis in MSM Taking HIV Pre-exposure Prophylaxis (PrEP)

The study involves a randomized placebo controlled trial that aims to assess if a mouthwash (Listerine cool mint, LCM) is able to reduce the cumulative incidence of gonorrhoea (Ng), chlamydia (Ct) and syphilis in men who have sex with men and receiving preexposure prophylaxis (PrEP) at the Institute of Tropical Medicine (ITM).

Study Overview

• Status: Terminated
• Conditions: Sexually Transmitted Diseases
• Intervention / Treatment: Other: Mouthwash with LCM; Other: Mouthwash with placebo

Detailed Description

The study aims to assess if there is a difference in the incidence rate of gonorrhea, chlamydia and syphilis detected at any site whilst individuals are on daily and pre/post sex Listerine cool mint (LCM) vs. placebo mouthwash.

The study has a double-blind, cross-over design, in which subjects will be screened at the ITM and, if eligible, will be enrolled and randomized to group 1 (LCM) or group 2 (placebo). After 3 months, a crossover will occur and subjects will switch to the other intervention. Each participant will therefore be enrolled for 6 months (2 x 3 months, no wash out period).

Subjects will be recruited from the existing PrEP cohort at the Institute of Tropical Medicine Antwerp. A total of 320 subjects will be recruited (160 in each arm).

• Study Type: Interventional
• Enrollment (Actual): 343
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Antwerp, Belgium, 2000
    • Institute of Tropical Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Men aged 18 or more
• Enrolled in Belgian PrEP program at ITM
• Has had sex with another man in the previous year
• Has had a symptomatic or asymptomatic STI (Ct/Ng/syphilis) in the previous 2 years
• Willing to be enrolled in the cohort for 6 months and attend 3 monthly follow up visits
• Willing to comply with the mouthwash study schema and willing to ask their casual partners to mouthwash pre- and post-sex
• Prepared to fill out the online diary once a week
• Able and willing to provide written informed consent

Exclusion Criteria:

• Currently using a mouthwash and unwilling to cease use of this mouthwash
• Enrolment in another interventional trial
• Tests HIV positive at screening

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LCM, then placebo; Mouthwash with LCM for 3 months followed by mouthwash with placebo for 3 months.	Other: Mouthwash with LCM; Subjects will mouthwash daily with LCM and before/after sex; Other: Mouthwash with placebo; Subjects will mouthwash daily with placebo and before/after sex
Experimental: Placebo, then LCM; Mouthwash with placebo for 3 months followed by mouthwash with LCM for 3 months	Other: Mouthwash with LCM; Subjects will mouthwash daily with LCM and before/after sex; Other: Mouthwash with placebo; Subjects will mouthwash daily with placebo and before/after sex

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Counts of Ng Plus Ct Plus Syphilis in Each Study Arm for Each Period	The sum of new diagnoses of Gonnorhea (Ng), Chlamydia (Ct) and syphilis in a 3 month period on LCM/placebo. Each participant can only contribute one diagnosis of Ct and one diagnosis of Ng per visit - regardless of number of sites infected. Thus each participant can contribute up to 3 diagnoses (Ct/Ng/syphilis) at each visit. The diagnosis of Ng and Ct will be made via molecular testing and syphilis via Rapid Plasma Reagin test (RPR) and Treponema Pallidum Antibodies tests (TPA) according to currently used European case definitions.	3-month period following each intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in Incidence Rate of Pharyngeal Ng Between Each Study Arm for Each Period	Incidence rate of new pharyngeal Ng cases in each allocation arm for each study period of 3 months.	3-month period following each intervention
Difference in Incidence Rate of Ct (Combined Pharyngeal, Urethral and Rectal) Between Each Study Arm for Each Period	Incidence rate of new Ct cases in each allocation arm (LCM and placebo) for each study period of 3 months.	3-month period following each intervention
Difference in Incidence Rate of Syphilis Between Periods on LCM vs. Placebo	Incidence rate of new syphilis cases in each allocation arm (LCM and placebo) for each study period of 3 months.	3-month period following each intervention
Proportion of Days That Mouthwash is Used on a Daily Basis and Proportion of Casual Sex Contacts When Mouthwash is Used Pre or Post Sex	Daily: Proportion of days in study used mouthwash at least daily Post sex: Proportion of casual sexual contacts in study when mouthwash used post sex. Pre sex: proportion of casual sexual contacts in study when mouthwash used pre sex	6-month period
Difference in Incidence Rate of Ng Plus Ct Plus Syphilis Between LCM and Placebo After Controlling for Adherence With Daily and Pre/Post Sex Mouthwash	Incidence rate of Ng, Ct and syphilis between both groups (LCM and placebo) post controlling for adherence to mouthwash	3-month period following each intervention
Difference in Cumulative Numbers of Antibiotics Used Between Periods on LCM vs. Placebo	Cumulative number of antibiotics used between both groups (LCM and placebo) for each period	3-month period following each intervention

Collaborators and Investigators

• Sponsor: Institute of Tropical Medicine, Belgium

Publications and helpful links

General Publications

• Van Dijck C, Tsoumanis A, Rotsaert A, Vuylsteke B, Van den Bossche D, Paeleman E, De Baetselier I, Brosius I, Laumen J, Buyze J, Wouters K, Lynen L, Van Esbroeck M, Herssens N, Abdellati S, Declercq S, Reyniers T, Van Herrewege Y, Florence E, Kenyon C. Antibacterial mouthwash to prevent sexually transmitted infections in men who have sex with men taking HIV pre-exposure prophylaxis (PReGo): a randomised, placebo-controlled, crossover trial. Lancet Infect Dis. 2021 May;21(5):657-667. doi: 10.1016/S1473-3099(20)30778-7. Epub 2021 Mar 4.

Study record dates

Study Major Dates

• Study Start (Actual): April 3, 2019
• Primary Completion (Actual): June 15, 2020
• Study Completion (Actual): June 15, 2020

Study Registration Dates

• First Submitted: March 13, 2019
• First Submitted That Met QC Criteria: March 18, 2019
• First Posted (Actual): March 19, 2019

Study Record Updates

• Last Update Posted (Actual): May 7, 2021
• Last Update Submitted That Met QC Criteria: April 12, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Keywords: Chlamydia; Gonorrhea; STI; Syphilis; Listerine
• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Communicable Diseases; Disease Attributes; Sexually Transmitted Diseases
• Other Study ID Numbers: ITM201801

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes

IPD Plan Description

Data sharing for the PreGo trial will comply with ITMs Data Sharing Policy.

Study data might be made available for secondary research and analyses to external researchers by means of a managed access procedure within 12 months of publication date. Because of privacy concerns, access requests will be reviewed and approved prior to release by ITMs Data Access Committee. Requests for access can be made centrally through:

https://www.itg.be/E/data-sharing-open-access The possibility of sharing (anonymized) study data is also mentioned in the Informed Consent Form and approved by the Ethics Committees that approved the initial PreGo clinical trial protocol.

• IPD Sharing Time Frame: Available in clinicaltrials.gov
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No