Superiority of On-demand PrEP Versus PEP on Using Doxycycline for Preventing STI in MSM (NCT06188442) | Clinical Trial Compass
Active — Not RecruitingPhase 4
Superiority of On-demand PrEP Versus PEP on Using Doxycycline for Preventing STI in MSM
Hong Kong300 participantsStarted 2025-03-29
Plain-language summary
The goal of this clinical trial is to compare the effectiveness of doxycycline taken for on-demand pre-exposure prophylaxis (DoxyODPrEP) and its post-exposure use (DoxyPEP) in preventing bacterial sexually transmitted infections (STI), including chlamydia, gonorrhoea, and syphilis among men who have sex with men (MSM). The main questions it aims to answer are:
1. Is DoxyODPrEP superior to DoxyPEP?
2. Are both regimens safe?
3. Does the MSM community accept the use of doxycycline to prevent bacterial STI?
Participants will be asked to take doxycycline according to the study arm they are randomly assigned to, and attend regular clinical follow-ups during the 2-year observation period. Researchers will compare the bacterial STI incidences between the two groups to see if DoxyODPrEP is superior to DoxyPEP.
Who can participate
Age range
18 Years
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* has had sex with another male in the past six months
* normally reside in Hong Kong
* can communicate in written and spoken Chinese or English
* willing and able to give written informed consent
* being willing and able to attend scheduled study clinic visits
* at risk of STI (had condomless sex with more than one man in the past 12 months, history of STI diagnosis in the past 12 months, inclination to have condomless sex, and other HIV-PrEP-eligible criteria)
Exclusion Criteria:
* Being allergic to tetracycline class medicines
* Currently taking medications that are contraindicated with doxycycline
* Using antibiotics for more than 14 days in the month preceding enrolment
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Time to the first episode of gonorrhoea after the enrolment visit
Timeframe: Months 1 to 24
2
Time to the first episode of chlamydia after the enrolment visit
Timeframe: Months 1 to 24
3
Time to the first episode of syphilis after the enrolment visit