DOXYCYCLINE for Sexually transmitted infections

Inclusion criteria

• {"criterion_text":"- Able and willing to provide informed consent in Dutch or English and adhere to the study procedures\n- Aged 18 years or older\n- Assigned male sex at birth\n- Identifying as gay, bisexual or other men who have sex with men or transgender women\n- Enrolled in PrEP care\n- Being HIV negative\n- Reporting having had condomless anal sex with at least one non-steady partner in the preceding year"}

Exclusion criteria

• {"criterion_text":"- Hypersensitivity to doxycycline or any substance used in the IMP\n- Concomitant use of medication interacting with doxycycline\n- Any contra-indication to the use of doxycycline, as mentioned in the summary of product characteristics"}

Primary endpoints

• {"endpoint_text":"- Incidence rate ratio of NG, CT, and TP infections in the W-DoxyPEP vs ED-DoxyPEP arms","definition_or_measurement_approach":"Incidence rate ratio comparing incidence rates of Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT) and Treponema pallidum (TP) infections between weekly doxyPEP (W-DoxyPEP) and event-driven doxyPEP (ED-DoxyPEP) arms."}

Secondary endpoints

• {"endpoint_text":"- Rate ratio of tetracyclines, macrolides, cephalosporins, and penicillins in the W-DoxyPEP vs ED-DoxyPEP arms\n- MIC distribution (doxycycline/cefixime/ciprofloxacin) of commensal Neisseria spp., oral streptococci and E. coli in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of symptomatic NG infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of symptomatic CT infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of symptomatic TP infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of all NG infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of all CT infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Incidence rate ratio of all TP infections in the W-DoxyPEP vs ED-DoxyPEP arms\n- Tetracycline MIC distribution of NG isolates in the W-DoxyPEP vs ED-DoxyPEP arms\n- participants' perception/experience, preference, and acceptability in using doxyPEP\n- Cost of integrating W-DoxyPEP vs ED-DoxyPEP in routine HIV-PrEP follow-up, if the strategy is proved to be effective, incremental cost per STI avoided/Quality of life Adjusted Life Years (QALY) gained","definition_or_measurement_approach":"Secondary endpoints include comparative rate ratios of antibiotic use (tetracyclines, macrolides, cephalosporins, penicillins), MIC distributions for specified organisms and antibiotics, incidence rate ratios for symptomatic and all infections by pathogen between arms, participant-reported perceptions/acceptability, and cost-effectiveness measures (incremental cost per STI avoided / QALY). Specific measurement methods (e.g. laboratory assays, survey instruments, economic evaluation methods) are referenced in the protocol but not detailed in the provided CTIS JSON."}

Belgium

Earliest CTIS Part Ii Submission Date

20-02-2026

Latest Decision Or Authorization Date

10-03-2026

Processing Time Days

18

Number Of Sites

1

Number Of Participants

556

Primary sponsor

Full Name

Institute Of Tropical Medicine

Organisation Type

Hospital/Clinic/Other health care facility

Country Of Registered Address

Belgium