Superiority of On-demand PrEP Versus PEP on Using Doxycycline for Preventing STI in MSM

Gonorrhea Clinical Trial

Official title:

Superiority of On-demand Pre-exposure Prophylaxis Versus Post-exposure Prophylaxis on Using Doxycycline for Preventing Sexually Transmitted Infections in Men Who Have Sex With Men

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06188442
• Other study ID #: 23220262
• Status: Not yet recruiting
• Phase: Phase 4
• Start date: April 2024
• Est. completion date: March 2027

Study information

• Verified date: December 2023
• Source: Chinese University of Hong Kong
• Contact: Secretariat
• Phone: 22528812
• Email: ceid[@]med.cuhk.edu.hk
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

Participants would be randomly assigned to either DoxyODPrEP or DoxyPEP arm, and be instructed to take doxycycline with the respective dosing schedule. They would be followed up for 24 months for nucleic acid amplification test (NAAT) and antibody tests against bacterial STI, namely chlamydia, gonorrhoea, and syphilis. The subjects and investigators would not be blinded due to its open-label nature, as the two arms' dosing schedules are different. Participants in the DoxyODPrEP arm would be instructed to take two doxycycline hyclate 100mg capsules orally 2-24 hours before sex, and one 100mg capsule each 24 and 48 hours after loading dose. If they have sex within 48 hours after the loading dose, they would be asked to continue a daily 100mg until two days after the last sex. Participants in the DoxyPEP arm would be instructed to take two doxycycline hyclate 100mg capsules orally within 24 hours and up to 72 hours after each sex. At each clinic visit, urine, and pharyngeal and rectal swabs would be self-collected on-site by the participants following instructions. Pill count would be performed for each follow-up visit.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 300
• Est. completion date: March 2027
• Est. primary completion date: October 2026
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Chlamydia
• Gonorrhea
• Sexually Transmitted Diseases
• Sexually Transmitted Diseases, Bacterial
• Syphilis

Intervention

Drug:
• DoxyODPrEP
Participants in the DoxyODPrEP arm would be instructed to take two doxycycline hyclate 100mg capsules orally 2-24 hours before sex, and one 100mg capsule each 24 and 48 hours after loading dose. If they have sex within 48 hours after the loading dose, they would be asked to continue a daily 100mg until two days after the last sex
• DoxyPEP
Participants in the DoxyPEP arm would be instructed to take two doxycycline hyclate 100mg capsules orally within 24 hours and up to 72 hours after each sex.

Locations

Country	Name	City	State
Hong Kong	Stanley Ho Centre for Emerging Infectious Diseases	Sha Tin

Sponsors (1)

Lead Sponsor	Collaborator
Chinese University of Hong Kong

Country where clinical trial is conducted

Hong Kong, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time to the first episode of gonorrhoea after the enrolment visit	Time to the first episode of gonorrhoea after the enrolment visit	Months 1 to 24
Primary	Time to the first episode of chlamydia after the enrolment visit	Time to the first episode of chlamydia after the enrolment visit	Months 1 to 24
Primary	Time to the first episode of syphilis after the enrolment visit	Time to the first episode of syphilis after the enrolment visit	Months 1 to 24
Secondary	Safety profile	Percentage of participants experiencing adverse events and the associated grades	Months 1 to 24
Secondary	Acceptability of regimens	Percentage of participants accepted the regimen	Months 1 to 24
Secondary	Retention	Percentage of participants remained during the follow-up period	Months 1 to 24
Secondary	Time to the first episode of HIV after the enrolment visit	Time to the first episode of HIV after the enrolment visit	Months 1 to 24