SyphilisPhase 4NCT02864550

Oral Doxycycline for the Prevention of Syphilis in Men Who Have Sex with Men (DaDHS)

A Phase 4 study testing Doxycycline in people with Syphilis and Sexually Transmitted Infections, run by British Columbia Centre for Disease Control at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 years and older, men only
Conditions the study is for: Syphilis, Sexually Transmitted Infections
What is being tested?: Doxycycline
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 52 participants
Where: 1 siteCanada
Study dates: 15 Aug 2019to 31 Dec 2024
Phase: Phase 4
Are there results?: None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
Men only
No healthy volunteers
Adult, Older adult

The inclusion criteria for this study are as follows:

Males, ≥ 18 years of age at baseline;
Self-reported MSM status;
Self-report condomless anal sex with a man within the last 6 months;
Laboratory documentation of HIV-1 infection;
Prior diagnosis of early/infectious syphilis (i.e. primary, secondary or early latent) within preceding 36 months (defined on the basis of a new positive serum rapid plasma reagin (RPR) test, or ≥2-dilution rise in titre if previous syphilis, or positive darkfield microscopy result or T. pallidum direct fluorescent antibody test or PCR from a primary lesion);
Able to provide informed consent.

The exclusion criteria for this study are as follows:

Known allergy or intolerance to doxycycline or tetracyclines;
A known diagnosis of myasthenia gravis;
Use of medications which could lower doxycycline levels, including barbiturates, phenytoin and carbamazepine;
Individuals using isotretinoin;
Any individual capable of getting pregnant.

Trial locations and contacts

1 site in 1 country.

Canada1 site

British Columbia Centre for Disease Control
Vancouver, British Columbia, V5Z 4R4

Other trials in Canada

About this study

Official title: A Randomized, Placebo-controlled Trial of Oral Doxycycline for the Prevention of Syphilis in HIV-positive Men Who Have Sex with Men (MSM)

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.

Read the detailed description

Syphilis disproportionately impacts gbMSM:

Syphilis remains an important cause of morbidity in gbMSM. Up to 75% of early syphilis infections occur in gbMSM - a population with syphilis rates nearly 10-fold higher than in those who are HIV negative. In Canada's urban centres, 2/3 of syphilis cases are in HIV-positive gbMSM, and re-infection remains high. HIV co-infection with syphilis has important implications for HIV management. Syphilis may increase HIV viral load levels in virologically suppressed individuals, and genital ulcers increase the risk of HIV transmission and acquisition.

The era of novel, biomedical prevention technologies:

Significant advancements have shaped the past two decades of HIV care. Antiretroviral therapy (ART) has substantially reduced HIV-associated morbidity and mortality and extended life expectancy to near-normal levels. With reduced morbidity and mortality associated with HIV, gbMSM may also be changing their sexual behaviours. Seroadaptive strategies, such as serosorting (selecting sexual partners of the same serostatus) and seropositioning (selecting a sexual position to minimize the risk of HIV transmission) are common among gbMSM. While this may be mitigating the risk of HIV transmission or acquisition, there is evidence to suggest that decreasing condom use may contribute to a rise in syphilis and other bacterial STIs in high-risk populations. Further, new evidence has emerged demonstrating the efficacy of HIV PrEP in preventing HIV acquisition. The combination use of tenofovir/emtricitabine was shown in the Pre-exposure Prophylaxis Initiative (iPREX) trial to reduce the risk of HIV acquisition by 44% in HIV-negative gbMSM when taken daily as PrEP. Among those with detectable drug levels, the risk reduction was > 90%.

A role for PrEP in other STIs? The exciting developments in HIV prevention have encouraged investigators to expand this strategy to the prevention of other STIs, a modality previously shown to be acceptable to gbMSM. A recent pilot study randomized participants to receive either the antimicrobial doxycycline daily or a monetary incentive to remain STI-free throughout the study period. After 48 weeks, those receiving doxycycline were significantly less likely to be diagnosed with any STI (odds ratio: 0.27; 95% confidence interval: 0.09-0.83). Though there was also a trend toward benefit for doxycycline in specifically preventing syphilis, significance was not achieved for this outcome.

The first large-scale syphilis PrEP study:

Given the rising rates of syphilis and its disproportionate impact on HIV-positive gbMSM, there is an urgent need to replicate this study on a broader scale. This proposed study will contribute to this field by being - to the investigators' knowledge - the first large-scale, methodologically rigorous trial of syphilis PrEP, and has the potential to provide a completely novel and innovative tool to the syphilis prevention armamentarium. It will provide insight on whether daily doxycycline is an efficacious PrEP intervention for the prevention of syphilis and other bacterial STIs, as well as shedding light on issues relating to its feasibility as a prevention tool, including its safety, tolerability, how well individuals adhere to it, and its impact on the development of antimicrobial resistance. These outcomes are directly in line with the planned outputs of this study, and have the potential to drastically shift how people think about and manage syphilis and other STI prevention in gbMSM.

Primary objective

To assess feasibility of using daily doxycycline PrEP, as defined by:
Evaluation of feasibility of recruitment for a larger study i. Proportion of participants approached for study who are eligible and agree to participate.
Adherence to 24 and 48 weeks of study drug (doxycycline or placebo) i. Determine proportion of individuals with >95% adherence to study drug over 24 and 48 weeks ii. Proportion of individuals in the doxycycline arm with therapeutic doxycycline plasma level at each study visit.
Tolerability of doxycycline i. Comparison of grade 3 or 4 adverse events in those receiving doxycycline vs. placebo ii. Comparison of the proportion of individuals with adverse event-related discontinuation of study drug in each arm 2.2 Secondary objectives
To evaluate antimicrobial resistance over time.
Change in proportion of participants with evidence of tetracycline class resistance in common flora, namely Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae from baseline to 24 and 48 weeks.
To evaluate changes in sexual activity reported by study participants over the study period.
To compare syphilis incidence between those in the doxycycline vs. placebo arms.
To describe frequency of other STIs diagnosed in study participants over the study period. Exploratory objectives will include:
To changes in the rectal microbiome of study participants from baseline to 24 and 48 weeks after initiation of doxycycline.

Conditions: Syphilis, Sexually Transmitted Infections
Being tested: Doxycycline, Placebo
Keywords: Men who have sex with men, Human immunodeficiency virus, Doxycycline, Tetracycline
Medical subject headings: Syphilis, Sexually Transmitted Diseases, Homosexuality, Acquired Immunodeficiency Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

DoxycyclineDrug
doxycycline 100mg orally daily
PlaceboOther
placebo capsule identical in appearance, taste, and size to the capsule provided to the intervention group

Study groups in NCT02864550
Study group	Role	What they receive
Doxycycline arm	Experimental	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. Receives: Drug: Doxycycline
Placebo arm	Placebo comparator	Participants in this control group will receive a placebo capsule identical in appearance, taste, and size to the capsule provided to the intervention group. Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

To assess the proportion of participants who are eligible and consent to participate amongst those approached.
To determine the feasibility of daily syphilis PrEP
Measured: 15 months
To assess the proportion of participants reporting > 95% adherence to study drug, according to self-report and pill counts.
To determine the feasibility of daily syphilis PrEP
Measured: 15 months
To assess the proportion of individuals with therapeutic doxycycline drug level (defined at ≥ 1000 ng/mL) at each study time point.
To determine the feasibility of daily syphilis PrEP
Measured: 15 months
To assess the proportion of individuals reporting grade 3 or 4 adverse events in each study arm.
To determine the feasibility of daily syphilis PrEP
Measured: 15 months
Proportion of individuals with adverse event-related study drug discontinuation in each study arm.
To determine the feasibility of daily syphilis PrEP
Measured: 15 months

Secondary outcomes (4)

To assess the proportion of individuals with evidence of tetracycline class resistance in common flora (Staphylococcus aureus, Streptococcus pyogene and Streptococcus pneumoniae)
To evaluate tetracycline class resistance in common flora (i.e. syphilis, gonorrhea, or chlamydia)
Measured: At 6 and 12 months
To assess the changes in sexual risk behaviour will be calculated by comparing risk parameters (i.e. number partners, number of anal sexual encounters that were condomless) from pre-PrEP initiation to the study period.
Change in sexual behaviour will also be compared between study arms.
Measured: 15 months
To assess the incidence of early syphilis infection
To evaluate syphilis and other STI incidence over the study period.
Measured: 15 months
To assess the incidence of gonorrhea or chlamydia infection
To evaluate syphilis and other STI incidence over the study period.
Measured: 15 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

15 Aug 201931 Dec 2024

First posted12 Aug 2016 (estimated)
Study start15 Aug 2019
Primary completion5 Apr 2024
Study completion31 Dec 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (25)Papers the sponsor has linked to this study.
Other trials for SyphilisStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 4
Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 52 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02864550
Sponsor's protocol ID: BritishCCDC2
Status last verified: Feb 2025
First submitted: 9 Aug 2016
Last updated: 12 Feb 2025
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

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 VG, Gardner SL, Moravan V, Tan DH, Grewal R, Raboud J, Bayoumi AM, Kaul R, Mazzulli T, McGee F, Rourke SB; OHTN Cohort Study Team. High incidence of diagnosis with syphilis co-infection among men who have sex with men in an HIV cohort in Ontario, Canada. BMC Infect Dis. 2015 Aug 20;15:356. doi: 10.1186/s12879-015-1098-2.
PubMed 26289937
Bolan RK, Beymer MR, Weiss RE, Flynn RP, Leibowitz AA, Klausner JD. Doxycycline prophylaxis to reduce incident syphilis among HIV-infected men who have sex with men who continue to engage in high-risk sex: a randomized, controlled pilot study. Sex Transm Dis. 2015 Feb;42(2):98-103. doi: 10.1097/OLQ.0000000000000216.
PubMed 25585069
Grant RM, Lama JR, Anderson PL, McMahan V, Liu AY, Vargas L, Goicochea P, Casapia M, Guanira-Carranza JV, Ramirez-Cardich ME, Montoya-Herrera O, Fernandez T, Veloso VG, Buchbinder SP, Chariyalertsak S, Schechter M, Bekker LG, Mayer KH, Kallas EG, Amico KR, Mulligan K, Bushman LR, Hance RJ, Ganoza C, Defechereux P, Postle B, Wang F, McConnell JJ, Zheng JH, Lee J, Rooney JF, Jaffe HS, Martinez AI, Burns DN, Glidden DV; iPrEx Study Team. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010 Dec 30;363(27):2587-99. doi: 10.1056/NEJMoa1011205. Epub 2010 Nov 23.
PubMed 21091279
Grant RM, Anderson PL, McMahan V, Liu A, Amico KR, Mehrotra M, Hosek S, Mosquera C, Casapia M, Montoya O, Buchbinder S, Veloso VG, Mayer K, Chariyalertsak S, Bekker LG, Kallas EG, Schechter M, Guanira J, Bushman L, Burns DN, Rooney JF, Glidden DV; iPrEx study team. Uptake of pre-exposure prophylaxis, sexual practices, and HIV incidence in men and transgender women who have sex with men: a cohort study. Lancet Infect Dis. 2014 Sep;14(9):820-9. doi: 10.1016/S1473-3099(14)70847-3. Epub 2014 Jul 22.
PubMed 25065857
Pang LW, Limsomwong N, Boudreau EF, Singharaj P. Doxycycline prophylaxis for falciparum malaria. Lancet. 1987 May 23;1(8543):1161-4. doi: 10.1016/s0140-6736(87)92141-6.
PubMed 2883488
Sehgal SC, Sugunan AP, Murhekar MV, Sharma S, Vijayachari P. Randomized controlled trial of doxycycline prophylaxis against leptospirosis in an endemic area. Int J Antimicrob Agents. 2000 Feb;13(4):249-55. doi: 10.1016/s0924-8579(99)00134-x.
PubMed 10755239
Patton ME, Su JR, Nelson R, Weinstock H; Centers for Disease Control and Prevention (CDC). Primary and secondary syphilis--United States, 2005-2013. MMWR Morb Mortal Wkly Rep. 2014 May 9;63(18):402-6.
PubMed 24807239
Jin F, Prestage GP, Zablotska I, Rawstorne P, Imrie J, Kippax SC, Donovan B, Templeton DJ, Kaldor JM, Grulich AE. High incidence of syphilis in HIV-positive homosexual men: data from two community-based cohort studies. Sex Health. 2009 Dec;6(4):281-4. doi: 10.1071/SH09060.
PubMed 19917195
Ling DI, Janjua NZ, Wong S, Krajden M, Hoang L, Morshed M, Achen M, Murti M, Lester RT, Wong J, Ogilvie G, Gilbert M. Sexually transmitted infection trends among gay or bisexual men from a clinic-based sentinel surveillance system in British Columbia, Canada. Sex Transm Dis. 2015 Mar;42(3):153-9. doi: 10.1097/OLQ.0000000000000250.
PubMed 25668648
Ogilvie GS, Taylor DL, Moniruzzaman A, Knowles L, Jones H, Kim PH, Rekart ML. A population-based study of infectious syphilis rediagnosis in British Columbia, 1995-2005. Clin Infect Dis. 2009 Jun 1;48(11):1554-8. doi: 10.1086/598997.
PubMed 19402790
Jarzebowski W, Caumes E, Dupin N, Farhi D, Lascaux AS, Piketty C, de Truchis P, Bouldouyre MA, Derradji O, Pacanowski J, Costagliola D, Grabar S; FHDH-ANRS CO4 Study Team. Effect of early syphilis infection on plasma viral load and CD4 cell count in human immunodeficiency virus-infected men: results from the FHDH-ANRS CO4 cohort. Arch Intern Med. 2012 Sep 10;172(16):1237-43. doi: 10.1001/archinternmed.2012.2706.
PubMed 22826097
Fleming DT, Wasserheit JN. From epidemiological synergy to public health policy and practice: the contribution of other sexually transmitted diseases to sexual transmission of HIV infection. Sex Transm Infect. 1999 Feb;75(1):3-17. doi: 10.1136/sti.75.1.3.
PubMed 10448335
Palella FJ Jr, Delaney KM, Moorman AC, Loveless MO, Fuhrer J, Satten GA, Aschman DJ, Holmberg SD. Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. HIV Outpatient Study Investigators. N Engl J Med. 1998 Mar 26;338(13):853-60. doi: 10.1056/NEJM199803263381301.
PubMed 9516219
Lohse N, Hansen AB, Pedersen G, Kronborg G, Gerstoft J, Sorensen HT, Vaeth M, Obel N. Survival of persons with and without HIV infection in Denmark, 1995-2005. Ann Intern Med. 2007 Jan 16;146(2):87-95. doi: 10.7326/0003-4819-146-2-200701160-00003.
PubMed 17227932

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Recruiting
A Study to Evaluate the Performance, and Usability of TruPlex HIV/HepB/Syphilis Rapid Test
HIV1 Infection, HIV 2 Infection
Active, not recruitingPhase 4
Periodic Presumptive Treatment vs. doxyPEP for STI Control in Kenyan MSM
Gonorrhea Male, Chlamydia (Male)
Not yet recruiting
Pilot HIV Self-Testing And Self-collected STI Testing Strategy for Sex Worker Empowerment Study
HIV, Syphilis
RecruitingPhase 3
Oral Amoxicillin Compared to Penicillin G Benzathine for the Treatment of Acquired Syphilis.
Syphilis Acquired
RecruitingPhase 2
Comprehensive Ambulatory Antibiotics for the Treatment of Congenital Syphilis
Syphilis, Congenital

All Syphilis trials

Study at a glance

From the registry record, last updated by the sponsor on 12 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Randomized, Placebo-controlled Trial of Oral Doxycycline for the Prevention of Syphilis in HIV-positive Men Who Have Sex with Men (MSM)
ClinicalTrials.gov ID: NCT02864550
Acronym / sponsor ID: BritishCCDC2
Conditions: Syphilis, Sexually Transmitted Infections
Keywords: Men who have sex with men, Human immunodeficiency virus, Doxycycline, Tetracycline
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 52 participants (actual)
Lead sponsor: British Columbia Centre for Disease ControlOther government
Study start: 15 Aug 2019 (actual)
Primary completion: 5 Apr 2024 (actual)
Study completion: 31 Dec 2024 (actual)
First posted: 12 Aug 2016 (estimated)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Syphilis disproportionately impacts gbMSM:

The era of novel, biomedical prevention technologies:

The first large-scale syphilis PrEP study:

Primary objective

To assess feasibility of using daily doxycycline PrEP, as defined by:
Evaluation of feasibility of recruitment for a larger study i. Proportion of participants approached for study who are eligible and agree to participate.
Adherence to 24 and 48 weeks of study drug (doxycycline or placebo) i. Determine proportion of individuals with >95% adherence to study drug over 24 and 48 weeks ii. Proportion of individuals in the doxycycline arm with therapeutic doxycycline plasma level at each study visit.
Tolerability of doxycycline i. Comparison of grade 3 or 4 adverse events in those receiving doxycycline vs. placebo ii. Comparison of the proportion of individuals with adverse event-related discontinuation of study drug in each arm 2.2 Secondary objectives
To evaluate antimicrobial resistance over time.
Change in proportion of participants with evidence of tetracycline class resistance in common flora, namely Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae from baseline to 24 and 48 weeks.
To evaluate changes in sexual activity reported by study participants over the study period.
To compare syphilis incidence between those in the doxycycline vs. placebo arms.
To describe frequency of other STIs diagnosed in study participants over the study period. Exploratory objectives will include:
To changes in the rectal microbiome of study participants from baseline to 24 and 48 weeks after initiation of doxycycline.

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 2

Arm	Type	Receives
Doxycycline arm	Experimental	Drug: DoxycyclineParticipants 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.
Placebo arm	Placebo comparator	Other: PlaceboParticipants in this control group will receive a placebo capsule identical in appearance, taste, and size to the capsule provided to the intervention group.

Who may qualify

Ages: 18 years and older
Sex: Male only
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Doxycyclinedoxycycline 100mg orally daily	Drug	Doxycycline arm
Placeboplacebo capsule identical in appearance, taste, and size to the capsule provided to the intervention group	Other	Placebo arm

Primary outcome

To assess the proportion of participants who are eligible and consent to participate amongst those approached.
Time frame: 15 months
To determine the feasibility of daily syphilis PrEP
To assess the proportion of participants reporting > 95% adherence to study drug, according to self-report and pill counts.
Time frame: 15 months
To determine the feasibility of daily syphilis PrEP
To assess the proportion of individuals with therapeutic doxycycline drug level (defined at ≥ 1000 ng/mL) at each study time point.
Time frame: 15 months
To determine the feasibility of daily syphilis PrEP
To assess the proportion of individuals reporting grade 3 or 4 adverse events in each study arm.
Time frame: 15 months
To determine the feasibility of daily syphilis PrEP
Proportion of individuals with adverse event-related study drug discontinuation in each study arm.
Time frame: 15 months
To determine the feasibility of daily syphilis PrEP

4 secondary outcomes

To assess the proportion of individuals with evidence of tetracycline class resistance in common flora (Staphylococcus aureus, Streptococcus pyogene and Streptococcus pneumoniae)
Time frame: At 6 and 12 months
To assess the changes in sexual risk behaviour will be calculated by comparing risk parameters (i.e. number partners, number of anal sexual encounters that were condomless) from pre-PrEP initiation to the study period.
Time frame: 15 months
To assess the incidence of early syphilis infection
Time frame: 15 months
To assess the incidence of gonorrhea or chlamydia infection
Time frame: 15 months

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Feb 2025.
BackgroundOntario Agency for Health Protection and Promotion (Public Health Ontario). Reportable Disease Trends in Ontario, 2013. Toronto, ON: Queen's Printer for Ontario; 2015.
Background: PubMed 26289937Burchell AN, Allen VG, Gardner SL, Moravan V, Tan DH, Grewal R, Raboud J, Bayoumi AM, Kaul R, Mazzulli T, McGee F, Rourke SB; OHTN Cohort Study Team. High incidence of diagnosis with syphilis co-infection among men who have sex with men in an HIV cohort in Ontario, Canada. BMC Infect Dis. 2015 Aug 20;15:356. doi: 10.1186/s12879-015-1098-2.
Background: PubMed 25585069Bolan RK, Beymer MR, Weiss RE, Flynn RP, Leibowitz AA, Klausner JD. Doxycycline prophylaxis to reduce incident syphilis among HIV-infected men who have sex with men who continue to engage in high-risk sex: a randomized, controlled pilot study. Sex Transm Dis. 2015 Feb;42(2):98-103. doi: 10.1097/OLQ.0000000000000216.
Background: PubMed 21091279Grant RM, Lama JR, Anderson PL, McMahan V, Liu AY, Vargas L, Goicochea P, Casapia M, Guanira-Carranza JV, Ramirez-Cardich ME, Montoya-Herrera O, Fernandez T, Veloso VG, Buchbinder SP, Chariyalertsak S, Schechter M, Bekker LG, Mayer KH, Kallas EG, Amico KR, Mulligan K, Bushman LR, Hance RJ, Ganoza C, Defechereux P, Postle B, Wang F, McConnell JJ, Zheng JH, Lee J, Rooney JF, Jaffe HS, Martinez AI, Burns DN, Glidden DV; iPrEx Study Team. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010 Dec 30;363(27):2587-99. doi: 10.1056/NEJMoa1011205. Epub 2010 Nov 23.
Background: PubMed 25065857Grant RM, Anderson PL, McMahan V, Liu A, Amico KR, Mehrotra M, Hosek S, Mosquera C, Casapia M, Montoya O, Buchbinder S, Veloso VG, Mayer K, Chariyalertsak S, Bekker LG, Kallas EG, Schechter M, Guanira J, Bushman L, Burns DN, Rooney JF, Glidden DV; iPrEx study team. Uptake of pre-exposure prophylaxis, sexual practices, and HIV incidence in men and transgender women who have sex with men: a cohort study. Lancet Infect Dis. 2014 Sep;14(9):820-9. doi: 10.1016/S1473-3099(14)70847-3. Epub 2014 Jul 22.
Background: PubMed 2883488Pang LW, Limsomwong N, Boudreau EF, Singharaj P. Doxycycline prophylaxis for falciparum malaria. Lancet. 1987 May 23;1(8543):1161-4. doi: 10.1016/s0140-6736(87)92141-6.
Background: PubMed 10755239Sehgal SC, Sugunan AP, Murhekar MV, Sharma S, Vijayachari P. Randomized controlled trial of doxycycline prophylaxis against leptospirosis in an endemic area. Int J Antimicrob Agents. 2000 Feb;13(4):249-55. doi: 10.1016/s0924-8579(99)00134-x.
Background: PubMed 24807239Patton ME, Su JR, Nelson R, Weinstock H; Centers for Disease Control and Prevention (CDC). Primary and secondary syphilis--United States, 2005-2013. MMWR Morb Mortal Wkly Rep. 2014 May 9;63(18):402-6.
Background: PubMed 19917195Jin F, Prestage GP, Zablotska I, Rawstorne P, Imrie J, Kippax SC, Donovan B, Templeton DJ, Kaldor JM, Grulich AE. High incidence of syphilis in HIV-positive homosexual men: data from two community-based cohort studies. Sex Health. 2009 Dec;6(4):281-4. doi: 10.1071/SH09060.
Background: PubMed 25668648Ling DI, Janjua NZ, Wong S, Krajden M, Hoang L, Morshed M, Achen M, Murti M, Lester RT, Wong J, Ogilvie G, Gilbert M. Sexually transmitted infection trends among gay or bisexual men from a clinic-based sentinel surveillance system in British Columbia, Canada. Sex Transm Dis. 2015 Mar;42(3):153-9. doi: 10.1097/OLQ.0000000000000250.
Background: PubMed 19402790Ogilvie GS, Taylor DL, Moniruzzaman A, Knowles L, Jones H, Kim PH, Rekart ML. A population-based study of infectious syphilis rediagnosis in British Columbia, 1995-2005. Clin Infect Dis. 2009 Jun 1;48(11):1554-8. doi: 10.1086/598997.
Background: PubMed 22826097Jarzebowski W, Caumes E, Dupin N, Farhi D, Lascaux AS, Piketty C, de Truchis P, Bouldouyre MA, Derradji O, Pacanowski J, Costagliola D, Grabar S; FHDH-ANRS CO4 Study Team. Effect of early syphilis infection on plasma viral load and CD4 cell count in human immunodeficiency virus-infected men: results from the FHDH-ANRS CO4 cohort. Arch Intern Med. 2012 Sep 10;172(16):1237-43. doi: 10.1001/archinternmed.2012.2706.
Individual participant dataSharing planned: No

Related trials for Syphilis

Recruiting
A Study to Evaluate the Performance, and Usability of TruPlex HIV/HepB/Syphilis Rapid Test
HIV1 Infection, HIV 2 Infection
Active, not recruitingPhase 4
Periodic Presumptive Treatment vs. doxyPEP for STI Control in Kenyan MSM
Gonorrhea Male, Chlamydia (Male)
Not yet recruiting
Pilot HIV Self-Testing And Self-collected STI Testing Strategy for Sex Worker Empowerment Study
HIV, Syphilis
RecruitingPhase 3
Oral Amoxicillin Compared to Penicillin G Benzathine for the Treatment of Acquired Syphilis.
Syphilis Acquired
RecruitingPhase 2
Comprehensive Ambulatory Antibiotics for the Treatment of Congenital Syphilis
Syphilis, Congenital

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Troy Grennan, MD principal investigator

BC Centre for Disease Control

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Doxycycline in people with Syphilis and Sexually Transmitted Infections, run by British Columbia Centre for Disease Control at 1 site in Canada.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Feb 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

To assess the proportion of participants who are eligible and consent to participate amongst those approached. (time frame: 15 months). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02864550, which also lists 25 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Feb 2025.