Evaluation of Doxycycline Post-exposure Prophylaxis to Reduce Sexually Transmitted Infections in PrEP Users and HIV-infected Men Who Have Sex With Men
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ClinicalTrials.gov Identifier: NCT03980223 |
Recruitment Status :
Recruiting
First Posted : June 10, 2019
Last Update Posted : March 13, 2020
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Condition or disease | Intervention/treatment | Phase |
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Gonorrhea Chlamydia Syphilis | Drug: Doxycycline Hyclate Delayed-Release 200 mg | Phase 4 |
The overarching goal is to assess the effectiveness of doxycycline PEP on incidence of STIs and tetracycline resistance among STIs and commensal bacteria to inform public health policy. Participants will be randomized 2:1, with a greater number receiving doxycycline PEP compared with the standard of care control, to maximize data on safety, tolerability, adherence coverage of sexual acts, and resistance data in participants randomized to doxycycline PEP, without negatively impacting power to measure effectiveness. Participants will be counseled about the preliminary effectiveness data from IPERGAY, and the potential for antimicrobial resistance (AMR) in STIs or other bacteria. Possibility of unreported doxycycline us in the control arm (contamination) will be monitored through retrospective batch testing of doxycycline metabolites in hair, to detect doxycycline use in the prior 3 months. 53
Eligible participants randomized 2:1 to receive PEP will receive open-label doxycycline 200 mg to be taken ideally within 24 hours but no later than 72 hours after condomless sexual contact (oral or anal). 200 mg of doxycycline will be taken at most once per 24 hour period regardless of the number of sexual acts occurring during this time period. Sexual activity will be recorded for both arms of the study (doxycycline PEP and control condition) by the participant using a smartphone application that will be adapted for study use; this will enable comparable assessment of risk in the two arms. PEP pill-taking will also be measured by the app to enable assessment of coverage of sex acts by PEP. Sexual activity and adherence will also be assessed in person at quarterly visits. STI testing will be conducted quarterly from three anatomic sites (pharyngeal, rectal and urinary) and blood for syphilis testing. Participants with a positive STI test will return for STI treatment and for swabs of the affected site for resistance testing; culture based for gonorrhea (GC) and molecular methods for CT and syphilis. Those with a serologic test that indicates a new syphilis infection will have swabs of any current active lesion as well as mucosal swabs from the oropharynx. Nares and oropharyngeal swabs will be obtained at baseline, 6 and 12 months to evaluate tetracycline resistance in S. aureus among carriers and in commensal Neisseria species.
Stool samples from 100 participants on the doxycycline PEP arm - 50 MSM living with HIV and 50 HIV uninfected MSM on pre-exposure prophylaxis (PrEP) - will be collected at baseline, 6 and 12 months to evaluate effects of intermittent doxycycline on the gut resistome, using 16s ribosomal RNA amplification to study tetracycline resistance genes. Rectal swabs will be collected and archived in all participants at baseline, 6, and 12 months for future studies of the impact of doxycycline PEP on the enteric microbiome and resistome.
Study population: This study will enroll 390 HIV-infected participants and 390 persons taking PrEP, for a total sample size of 780. An approximately equal number of participants in each of these cohorts (and in each study arm) will be enrolled in San Francisco and Seattle.
Current or planned initiation of PrEP use is an eligibility criterion for enrollment, because this population of MSM has high rates of STIs and are typically seen quarterly for PrEP visits. However, participants may opt to stop PrEP use at any time during the study without affecting their involvement in the study. Any HIV-uninfected participants who subsequently seroconvert will be managed clinically by the study site according to local practice (appropriate counseling, clinical evaluation and immediate linkage to clinical and psychosocial services). These participants will also be retained in the study unless they choose to discontinue study participation.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 780 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Open-label randomized clinical trial |
Masking: | None (Open Label) |
Primary Purpose: | Prevention |
Official Title: | Evaluation of Doxycycline Post-exposure Prophylaxis to Reduce Sexually Transmitted Infections in PrEP Users and HIV-infected Men Who Have Sex With Men |
Actual Study Start Date : | November 26, 2019 |
Estimated Primary Completion Date : | March 2023 |
Estimated Study Completion Date : | March 2024 |

Arm | Intervention/treatment |
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Experimental: Doxy PEP
Doxycycline 200mg in addition to standard of care STI testing and treatment
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Drug: Doxycycline Hyclate Delayed-Release 200 mg
200 mg of doxycycline taken by mouth after condomless sexual contact as post exposure prophylaxis (PEP) |
No Intervention: Control
The control arm will consist of standard of care STI testing and treatment
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- Incidence of GC, CT or syphilis [ Time Frame: 1 year ]Combined incidence of GC, CT, or early syphilis infection by by laboratory-based diagnosis

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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:
- Willing and able to give written informed consent
- Age ≥ 18 years
- Male sex at birth
- Previously HIV-diagnosed OR HIV-seronegative at the time of last test within the past month and a current prescription for PrEP (both daily or event-driven permitted) or plan to start PrEP within 30 days after the enrollment visit
- Condomless anal or oral sexual contact with ≥ 1 male sex-at-birth partners in the past 12 months
- Diagnosed with GC, CT or early syphilis (primary, secondary or early latent) in the past 12 months. Note: self report of STI is acceptable if documentation not available.
- Willing to use a smartphone app to record sexual practices (all participants) and doxycycline PEP (if assigned to PEP arm) if the participant possesses a smartphone Note: Possession of smartphone is not required for study participation. Study personnel will assist in obtaining a smartphone through locally available resources if participant does not have a phone.
Exclusion Criteria:
- Allergy to tetracycline class
- Current medications which may impact doxycycline metabolism or that are contraindicated with doxycycline, as per the prescribing information. These include systemic retinoids, barbiturates, carbamazepine, and phenytoin.
- Anticipated use of doxycycline during the coming 12 months for non-STI prevention (e.g., acne treatment).

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 ClinicalTrials.gov identifier (NCT number): NCT03980223
Contact: Anne Luetkemeyer, MD | 415-476-4082 ext 130 | Annie.Luetkemeyer@ucsf.edu | |
Contact: Connie Celum, MD, MPH | 206-520-3869 | ccelum@uw.edu |
United States, California | |
San Francisco City Clinic / San Francisco Department of Public Health | Recruiting |
San Francisco, California, United States, 94103 | |
Contact: Stephanie Cohen, MD 415-487-5503 Stephanie.Cohen@sfdph.org | |
Contact: Sundos Yassin 415-487-5533 Sundos.Yassin@sfdph.org | |
Principal Investigator: Stephanie Cohen, MD | |
University of California, San Francisco / Zuckerberg San Francisco General Hospital/UCSF | Recruiting |
San Francisco, California, United States, 94110 | |
Contact: Anne Luetkemeyer, MD 415-476-4082 ext 130 annie.luetkemeyer@ucsf.edu | |
Contact: Jay Dwyer, RN 415-476-4082 ext 353 jay.dwyer@ucsf.edu | |
Principal Investigator: Anne Luetkemeyer', MD | |
United States, Washington | |
University of Washington | Recruiting |
Seattle, Washington, United States, 98195 | |
Contact: Connie Celem, MD, MPH 206-520-3824 ccelum@uw.edu | |
Contact: Justice Quame-Amaglo 206-520-3866 quamaglo@uw.edu |
Principal Investigator: | Anne Luetkemeyer, MD | University of California, San Francisco |
Responsible Party: | University of California, San Francisco |
ClinicalTrials.gov Identifier: | NCT03980223 |
Other Study ID Numbers: |
DoxyPEP R01AI143439 ( U.S. NIH Grant/Contract ) |
First Posted: | June 10, 2019 Key Record Dates |
Last Update Posted: | March 13, 2020 |
Last Verified: | March 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Plan Description: | IPD will not be shared with other researchers outside of the study team |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | No |
HIV Post-Exposure Prophylaxis Men who have sex with men (MSM) |
Doxycycline HIV Pre-Exposure Prophylaxis Sexually transmitted infection |
Infection Gonorrhea Sexually Transmitted Diseases Syphilis Gram-Negative Bacterial Infections Bacterial Infections Sexually Transmitted Diseases, Bacterial Neisseriaceae Infections Virus Diseases |
Treponemal Infections Spirochaetales Infections Doxycycline Anti-Bacterial Agents Anti-Infective Agents Antimalarials Antiprotozoal Agents Antiparasitic Agents |