Doxycycline Intervention for Bacterial STI ChemoprOphylaxis (DISCO)
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)
1 other identifier
interventional
560
1 country
6
Brief Summary
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Jun 2023
Longer than P75 for not_applicable
6 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 12, 2021
CompletedFirst Posted
Study publicly available on registry
February 21, 2021
CompletedStudy Start
First participant enrolled
June 2, 2023
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 31, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
June 30, 2027
August 5, 2024
August 1, 2024
3.6 years
February 12, 2021
August 1, 2024
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
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 Outcomes (8)
Frequency of STIs over time
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
60 weeks
Proportion of participants who report acceptability, community norms and partner attitudes of STI PrEP and PEP based on responses from questionnaires
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
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.
Over 48 weeks
- +3 more secondary outcomes
Study Arms (2)
STI PrEP arm
EXPERIMENTALdoxycycline capsules 100mg orally daily for 12 months. Though the usual treatment dose of doxycycline is 100mg twice daily
STI PEP arm
EXPERIMENTALdoxycycline 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
Interventions
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
Eligibility Criteria
You may qualify if:
- Males, ≥ 18 years of age;
- 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;
- Intention to remain sexually active with more than one male partner in the next 12 months;
- At least one prior episode of a previously diagnosed and adequately treated syphilis, gonorrhea or chlamydia infection within 12 months prior to screening.
You may not qualify if:
- Known allergy to doxycycline or tetracyclines;
- Existing chronic or intermittent tetracycline or doxycycline use (e.g. for chronic osteomyelitis, acne).
- Use of medications which could lower doxycycline levels, including barbiturates, phenytoin and carbamazepine.
- Individuals currently using isotretinoin;
- Any individual capable of becoming pregnant.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (6)
Sheldon Chumir Centre
Calgary, Alberta, Canada
BC Centre for Disease Control
Vancouver, British Columbia, V5Z4R4, Canada
St. Joseph's Healthcare Hamilton
Hamilton, Ontario, Canada
The Ottawa Hospital
Ottawa, Ontario, Canada
St. Michael's Hospital
Toronto, Ontario, Canada
McGill University Health Centre
Montreal, Quebec, Canada
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Troy Grennan, MD
University of British Columbia
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER GOV
- Responsible Party
- SPONSOR INVESTIGATOR
- PI Title
- Principal Investigator
Study Record Dates
First Submitted
February 12, 2021
First Posted
February 21, 2021
Study Start
June 2, 2023
Primary Completion (Estimated)
December 31, 2026
Study Completion (Estimated)
June 30, 2027
Last Updated
August 5, 2024
Record last verified: 2024-08