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Oral Doxycycline for the Prevention of Syphilis in Men Who Have Sex With Men

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02864550
Recruitment Status : Not yet recruiting
First Posted : August 12, 2016
Last Update Posted : August 12, 2016
Information provided by (Responsible Party):
Jonathan Troy Grennan, British Columbia Centre for Disease Control

Brief Summary:
Syphilis is a sexually transmitted infection (STI) disproportionately affecting gay, bisexual and other men who have sex with men (gbMSM), with the potential for significant sequelae - particularly in those who are Human Immunodeficiency Virus (HIV)-positive. Rising rates of this STI have prompted a search for novel prevention solutions. A recent pilot study of daily doxycycline prophylaxis demonstrated promise as a novel STI prevention tool. This innovative approach to STI prevention has solid clinical precedent, both from the HIV pre-exposure prophylaxis (PrEP) literature, as well as doxycycline's use as prophylaxis for other infections. The overarching goal of this project is to determine whether the daily use of doxycycline is an efficacious and acceptable intervention for syphilis prevention in high-risk, HIV-positive gbMSM.

Condition or disease Intervention/treatment Phase
Syphilis Sexually Transmitted Infections Drug: Doxycycline Other: Placebo Early Phase 1

  Show Detailed Description

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 288 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Randomized, Placebo-controlled Trial of Oral Doxycycline for the Prevention of Syphilis in Men Who Have Sex With Men (MSM)
Study Start Date : November 2016
Estimated Primary Completion Date : March 2020
Estimated Study Completion Date : May 2020

Arm Intervention/treatment
Experimental: Doxycycline arm
Participants in this intervention group will receive doxycycline 100mg orally daily, which is available as a 100mg capsule. This single daily dose was chosen to maximize adherence, given the common use of once-daily Human Immunodeficiency Virus (HIV) pre-exposure prophylaxis (PrEP), as well as its efficacy as once-daily prophylaxis against malaria and its utility as dosing as infrequent as once weekly for another spirochete infection, leptospirosis.
Drug: Doxycycline
Placebo Comparator: Placebo arm
Participants in this control group will receive a placebo capsule identical in appearance, taste, and size to the capsule provided to the intervention group.
Other: Placebo

Primary Outcome Measures :
  1. Number of new (incident) syphilis cases [ Time Frame: Participants will be followed for 15 months ]
    Given that all participants will have had syphilis infection in the past, and thus their serology will reflect this, a new infection will be defined as a two titre (or four-fold) increase in rapid plasma reagin (RPR) (e.g. 1:2 to 1:8).

  2. Frequency of adverse events and discontinuations [ Time Frame: Participants will be followed for 15 months ]
    This will be captured via self-report at each study visit.

Secondary Outcome Measures :
  1. Number of new (incident) cases of any bacterial sexually transmitted infection (i.e. syphilis, gonorrhoea, or chlamydia) [ Time Frame: Participants will be followed for 15 months ]
  2. Number of doses of study medication taken per week [ Time Frame: Participants will be followed for 15 months ]
    Measured by (1) self-report; (2) pill counts at each study visit. Additionally, these outcomes will be corroborated with doxycycline serum drug levels.

  3. Increase in minimum inhibitory concentration (MIC) of either Staphylococcus aureus or Streptococcus pneumoniae to tetracyclines. [ Time Frame: Participants will be followed for 15 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Males, ≥ 18 years of age at baseline;
  2. History of any sexual activity with men;
  3. Laboratory documentation of Human Immunodeficiency Virus (HIV)-1 infection;
  4. At least one prior episode of a previously diagnosed and adequately treated syphilis infection within the three years prior to screening.

Exclusion Criteria:

  1. Known allergy or intolerance to doxycycline or tetracyclines;
  2. A known diagnosis of myasthenia gravis;
  3. Inability to provide informed consent.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02864550

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Contact: Troy Grennan, MD 604-707-5606

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Canada, British Columbia
British Columbia Centre for Disease Control Not yet recruiting
Vancouver, British Columbia, Canada, V5Z 4R4
Contact: Troy Grennan, MD    604-707-5606   
Sponsors and Collaborators
British Columbia Centre for Disease Control
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Principal Investigator: Troy Grennan, MD BC Centre for Disease Control

Ontario Agency for Health Protection and Promotion (Public Health Ontario). Reportable Disease Trends in Ontario, 2013. Toronto, ON: Queen's Printer for Ontario; 2015.
Burchell AN, Allen V, Tan D, et al. Variations in syphilis testing and diagnosis among MSM in HIV care in Ontario according to sexual behaviour (abstract). Can J Infect Dis Med Microbiol. 2014;25(Supp A).[20. Hart G. Syphilis tests in diagnostic and therapeutic decision making. Ann Intern Med. 1986;104(3):368.

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Responsible Party: Jonathan Troy Grennan, Physician Lead, HIV/STI program, BCCDC, British Columbia Centre for Disease Control Identifier: NCT02864550     History of Changes
Other Study ID Numbers: BritishCCDC2
First Posted: August 12, 2016    Key Record Dates
Last Update Posted: August 12, 2016
Last Verified: August 2016

Keywords provided by Jonathan Troy Grennan, British Columbia Centre for Disease Control:
Men who have sex with men
Human immunodeficiency virus

Additional relevant MeSH terms:
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Sexually Transmitted Diseases
Virus Diseases
Genital Diseases, Male
Genital Diseases, Female
Sexually Transmitted Diseases, Bacterial
Treponemal Infections
Gram-Negative Bacterial Infections
Bacterial Infections
Spirochaetales Infections
Anti-Bacterial Agents
Anti-Infective Agents
Antiprotozoal Agents
Antiparasitic Agents