Bacterial Sexually Transmitted Diseases Clinical Trial
Official title:
A Randomized Trial of Doxycycline Chemoprophylaxis for the Prevention of Sexually Transmitted Infections in Gay, Bisexual and Other Men Who Have Sex With Men (gbMSM)
There is a growing epidemic of the bacterial sexually transmitted infections (STIs) syphilis, chlamydia and gonorrhea worldwide; similarly concerning trends have been noted in Canada, where increases of over 160% have been seen in bacterial STIs over the last decade. In Canada, gay, bisexual, and other men who have sex with men (gbMSM) - including those living with HIV - are disproportionately impacted by bacterial STIs5,6These dramatic increases in bacterial STIs, the potential development of serious complications including AMR, and waning effectiveness of the promotion of conventional STI prevention tools (e.g. condoms), signals the need for novel STI prevention strategies and tools to mitigate STI-related complications. A rigorous randomized controlled trial will be conducted to compare STI PrEP vs. STI PEP and definitively assess the efficacy, safety, antimicrobial resistance profiles and costs associated with doxycycline-based STI prevention.
| Status | Recruiting |
| Enrollment | 560 |
| Est. completion date | June 30, 2027 |
| Est. primary completion date | December 31, 2026 |
| Accepts healthy volunteers | No |
| Gender | Male |
| Age group | 18 Years and older |
| Eligibility | Inclusion Criteria: 1. Males, = 18 years of age; 2. Any sexual activity (i.e. oral sex, insertive or receptive anal sex, with or without a condom) with more than one male partner in the preceding 12 months; 3. Intention to remain sexually active with more than one male partner in the next 12 months; 4. At least one prior episode of a previously diagnosed and adequately treated syphilis, gonorrhea or chlamydia infection within 12 months prior to screening. Exclusion Criteria: 1. Known allergy to doxycycline or tetracyclines; 2. Existing chronic or intermittent tetracycline or doxycycline use (e.g. for chronic osteomyelitis, acne). 3. Use of medications which could lower doxycycline levels, including barbiturates, phenytoin and carbamazepine. 4. Individuals currently using isotretinoin; 5. Any individual capable of becoming pregnant. |
| Country | Name | City | State |
|---|---|---|---|
| Canada | BC Centre for Disease Control | Vancouver | British Columbia |
| Lead Sponsor | Collaborator |
|---|---|
| Jonathan Troy Grennan | Canadian Institutes of Health Research (CIHR) |
Canada,
| Type | Measure | Description | Time frame | Safety issue |
|---|---|---|---|---|
| Primary | Plasma doxycycyline levels to determine efficacy of doxycycline chemoprophylaxis | To determine the efficacy of doxycycline chemoprophylaxis in preventing incident bacterial STI cases (syphilis, gonorrhea, and/or chlamydia, including LGV) | 60 weeks | |
| Secondary | Frequency of STIs over time | To describe frequency of syphilis, gonorrhea, and chlamydia incident infections among participants over the study period | 60 weeks | |
| Secondary | Proportion of individuals reporting grade 3 or 4 adverse events in each study arm as assessed by the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events | To determine the tolerability and safety of doxycycline chemoprophylaxis | 60 weeks | |
| Secondary | Proportion of participants who report acceptability, community norms and partner attitudes of STI PrEP and PEP based on responses from questionnaires | To determine the acceptability of doxycycline chemoprophylaxis | 60 weeks | |
| Secondary | Change in self-reported sexual activity defined as increases in condomless sexual acts and number of sexual partners based on responses from questionnaires | To evaluate the change in sexual behaviour reported by participants over the study period | 60 weeks | |
| Secondary | Proportion of individuals with evidence of tetracycline class resistance in common flora (Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae) at 24 and 48 weeks. | To evaluate antimicrobial resistance in bacterial STIs and common commensal pathogens over study period | Over 48 weeks | |
| Secondary | Proportion of cases with resistance to penicillins, tetracyclines or macrolides in syphilis, and tetracycline resistance in gonorrhea and chlamydia isolates taken from the anus, oral cavity or urethra. | To evaluate antimicrobial resistance in bacterial STIs and common commensal pathogens over study period | Over 48 weeks | |
| Secondary | Proportion of individuals with adverse event-related study drug discontinuation in each study arm | To determine the tolerability and safety of doxycycline chemoprophylaxis | Over 60 weeks | |
| Secondary | Rate of adherence to study treatment (STI PrEP vs. PEP) by participants. | To assess for superiority of doxycycline PrEP over PEP (if non-inferiority is shown) | Over 48 weeks |