An interventional study of Doxycycline Hyclate in Bacterial Sexually Transmitted Diseases, sponsored by Jonathan Troy Grennan. Recruiting at 6 sites in Canada. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-08-05.
Sponsored by Jonathan Troy Grennan · Not applicable, Interventional, and Prevention
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.
With the rising rates of STIs among gbMSM populations in Canada, there is an urgent need for novel interventions to prevent significant sequelae (e.g. neurosyphilis) and onward transmission of untreated infections. Despite longstanding public health efforts to encourage conventional strategies of STI prevention, gbMSM continue to bear the burden of syphilis which poses synergistic effects in the transmission of HIV. This study will add to this field through providing the first methodologically rigorous, prospective multicentre, open-label randomized controlled trial (RCT) of doxycycline-based STI PrEP (daily 100mg doxycycline) versus STI PEP (200mg doxycycline after exposure event) for the prevention of bacterial STIs among gbMSM over 15 months (60 weeks) of follow-up with adequate power to address drug efficacy in the prevention of bacterial STIs. Beyond the determination of efficacy, our trial will provide insight to the unique challenges of medication adherence through assessing the acceptability, tolerability and safety of therapy with doxycycline. This study aims to provide health care providers one additional tool to address the burden of STIs in populations with an increased likelihood of infection.
424 studies on the registry are indexed under Sexually Transmitted Diseases; 71 are open to participants now.
This study's planned enrollment of 560 is above the median of 470 across 346 interventional studies indexed under Sexually Transmitted Diseases.
Browse Sexually Transmitted Diseases studies →This is the only study on the registry with Jonathan Troy Grennan as lead sponsor.
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Exclusion Criteria:
doxycycline capsules 100mg orally daily for 12 months. Though the usual treatment dose of doxycycline is 100mg twice daily
Drug: Doxycycline Hyclate
doxycycline 200mg orally once within 24-72 hours following each sexual encounter deemed at risk (i.e. condomless anal or oral sex), to a maximum of six pills (i.e. 600 mg total) per week
Drug: Doxycycline Hyclate
STI PrEP arm: doxycycline capsules 100mg orally daily for 12 months STI PEP arm: doxycycline 200mg orally once within 24-72 hours following each sexual encounter deemed at risk (i.e. condomless anal or oral sex), to a maximum of six pills (i.e. 600 mg total) per week
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)
Time frame: 60 weeks
Frequency of STIs over time
To describe frequency of syphilis, gonorrhea, and chlamydia incident infections among participants over the study period
Time frame: 60 weeks
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
Time frame: 60 weeks
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
Time frame: 60 weeks
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
Time frame: 60 weeks
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
Time frame: Over 48 weeks
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
Time frame: Over 48 weeks
Proportion of individuals with adverse event-related study drug discontinuation in each study arm
To determine the tolerability and safety of doxycycline chemoprophylaxis
Time frame: Over 60 weeks
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)
Time frame: Over 48 weeks
Plan to share: Undecided — Our results will be targeted to four main groups of stakeholders: clinicians, public health, researchers, and community.The Community-Based Research Centre for Gay Men's Health, the Canadian AIDS Treatment Information Exchange (CATIE), and the AIDS Committee of Toronto will help facilitate KTE locally and nationally. We will disseminate our findings to a large, international audience of clinicians and public-health professionals by publishing in high-impact peer-reviewed journals.
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