Chlamydia FemalesPhase 4NCT07704957
A Randomized Controlled Trial of Doxycycline Post Exposure Prophylaxis to Prevent Incident Bacterial STIs Among Women in the United States
A Phase 4 study testing Doxycycline in people with Chlamydia Females and Gonorrhea Female, run by Tulane University.
Trial summary
The bacterial sexually transmitted infections (STIs) chlamydia, gonorrhea, and syphilis cause multiple adverse outcomes in women, and prevention strategies are critically needed. Read more about this study
- Who is it for?
- Ages 18 to 35 years, women only
- Conditions the study is for
- Chlamydia Females, Gonorrhea Female, Syphilis Female
- What is being tested?
- Doxycycline
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 519 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2027to 1 Apr 2032
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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 to 35 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Female
- Aged 18-35
- Reporting condomless vaginal sex with men AND least one of the following:
- diagnosis of CT, gonorrhea, syphilis, or trichomonas in the past year
- reporting 2 or more sexual partners in the past 6 months
- Plan to continue to be sexually active over the next year
- Have smartphone and be willing to engage with an app
- If HIV+: Viral load<200 copies/ml and CD4 count >200 cells/mm3
Who cannot join
- Pregnant, nursing, or intending to become pregnant
- Reported allergy to tetracyclines
- Liver disease or end-stage renal disease
- Non-English Speaking
- Taking concomitant medications which may impact doxycycline metabolism (e.g., systemic retinoids, antacids, barbiturates, carbamazepine, phenytoin, iron, warfarin, rifampin)
- Not willing to take doxy PEP or comply with study procedures
- Unable to provide informed consent
About this study
The bacterial sexually transmitted infections (STIs) chlamydia, gonorrhea, and syphilis cause multiple adverse outcomes in women, and prevention strategies are critically needed. This project will determine the efficacy of doxycycline post-exposure prophylaxis (doxy PEP) to prevent STIs among women through a phase IV, open-label, randomized controlled trial.
Read the detailed description
The bacterial sexually transmitted infections (STIs) chlamydia (CT), gonorrhea, and syphilis cause multiple adverse outcomes in women, and rates of these infections have increased dramatically over the past two decades. Prevention of these infections is now possible with the use of doxycycline post-exposure prophylaxis (doxy PEP), which has demonstrated efficacy in multiple studies conducted among men from high prevalence groups. However, only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result. Our proposed project seeks to evaluate doxy PEP efficacy among women in the United States through an open-label, randomized controlled trial (RCT) conducted in three jurisdictions (New Orleans, LA; Birmingham, AL; Chicago, IL) with high STI prevalence. Close adherence monitoring is critical given that the dPEP Kenya study's null result was likely related to poor medication adherence; thus, this trial will monitor and reinforce doxycycline adherence throughout the study using a novel PCheck app developed by our team, test urines for doxycycline levels on all participants, and hair on a nested cohort. The study's aim to conduct an RCT in 519 sexually active, non-pregnant women aged 18-35, randomizing 2:1 to better evaluate adverse events related to doxy PEP, powering the study on CT as the most commonly anticipated STI; sensitivity analyses will compare CT rates based on adherence measured by doxycycline levels in urine and by self-reported pill-taking. To execute these aims, we have assembled a multidisciplinary team with extensive expertise in the conduct of clinical trials, bioinformatics, biostatistics, infectious diseases epidemiology, STI prevention, the vaginal microbiome, behavioral health interventions, and qualitative science. MPIs Clement, Kissinger, and Muzny collectively have decades of collaborative experience enrolling priority populations in large clinical trials aimed to improve sexual health outcomes. Ultimately, this trial has the potential to have substantial public health impact, leading to a novel bacterial STI prevention intervention to reduce the undue burden of incident bacterial STIs among women.
- Conditions
- Chlamydia Females, Gonorrhea Female, Syphilis Female, Adherence, Prophylaxis, Prevention
- Being tested
- Doxycycline, Standard of Care (SOC)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DoxycyclineDrug
Also called Doxy PEP
Enrolled participants will be randomized 2:1 to receive 200 mg of doxy PEP taken within 24 hours of condomless sex versus standard of care. Only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result.
Standard of Care (SOC)Other
Enrolled participants will be randomized 2:1 to receive 200 mg of doxy PEP taken within 24 hours of condomless sex versus standard of care. Only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result.
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Experimental | 200 mg oral doxy PEP (N=346) Receives: Drug: Doxycycline |
| Control | Active comparator | Standard of care (i.e. no doxy PEP, N=173) Receives: Other: Standard of Care (SOC) |
What is being measured
The primary outcome is the main question the study is designed to answer.
chlamydia incidence
The primary outcome will be the number of CT infections over person-time (incidence rate).
Measured: Participants will be evaluated at baseline and quarterly for 48 weeks with STI testing at each visit.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2026
- Study start1 Jan 2027 (estimated)
- Primary completion28 Feb 2031 (estimated)
- Study completion1 Apr 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chlamydia FemalesStudies of the same condition, open and under way.
- More trials run by Tulane UniversityThe sponsor's other registered studies.
- 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 519 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tulane University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID), University of Alabama at Birmingham, Louisiana State University Health Sciences Center in New Orleans
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07704957
- Sponsor's protocol ID
- R01AI196614
- Status last verified
- Jul 2026
- First submitted
- 10 Jul 2026
- Last updated
- 15 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: STI lab tests results, surveys results from baseline and quarterly visits, app data, doxycycline drug levels by urinalysis, doxycycline hair levels
Study at a glance
From the registry record, last updated by the sponsor on 15 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial of Doxycycline Post Exposure Prophylaxis to Prevent Incident Bacterial STIs Among Women in the United States
- ClinicalTrials.gov ID
- NCT07704957
- Acronym / sponsor ID
- R01AI196614
- Conditions
- Chlamydia Females, Gonorrhea Female, Syphilis Female, Adherence, Prophylaxis, Prevention
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 519 participants (estimated)
- Lead sponsor
- Tulane UniversityUniversity, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID), University of Alabama at Birmingham, Louisiana State University Health Sciences Center in New Orleans
- Study start
- 1 Jan 2027 (estimated)
- Primary completion
- 28 Feb 2031 (estimated)
- Study completion
- 1 Apr 2032 (estimated)
- First posted
- 15 Jul 2026 (actual)
- 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.
The bacterial sexually transmitted infections (STIs) chlamydia, gonorrhea, and syphilis cause multiple adverse outcomes in women, and prevention strategies are critically needed. This project will determine the efficacy of doxycycline post-exposure prophylaxis (doxy PEP) to prevent STIs among women through a phase IV, open-label, randomized controlled trial.
Detailed description
The bacterial sexually transmitted infections (STIs) chlamydia (CT), gonorrhea, and syphilis cause multiple adverse outcomes in women, and rates of these infections have increased dramatically over the past two decades. Prevention of these infections is now possible with the use of doxycycline post-exposure prophylaxis (doxy PEP), which has demonstrated efficacy in multiple studies conducted among men from high prevalence groups. However, only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result. Our proposed project seeks to evaluate doxy PEP efficacy among women in the United States through an open-label, randomized controlled trial (RCT) conducted in three jurisdictions (New Orleans, LA; Birmingham, AL; Chicago, IL) with high STI prevalence. Close adherence monitoring is critical given that the dPEP Kenya study's null result was likely related to poor medication adherence; thus, this trial will monitor and reinforce doxycycline adherence throughout the study using a novel PCheck app developed by our team, test urines for doxycycline levels on all participants, and hair on a nested cohort. The study's aim to conduct an RCT in 519 sexually active, non-pregnant women aged 18-35, randomizing 2:1 to better evaluate adverse events related to doxy PEP, powering the study on CT as the most commonly anticipated STI; sensitivity analyses will compare CT rates based on adherence measured by doxycycline levels in urine and by self-reported pill-taking. To execute these aims, we have assembled a multidisciplinary team with extensive expertise in the conduct of clinical trials, bioinformatics, biostatistics, infectious diseases epidemiology, STI prevention, the vaginal microbiome, behavioral health interventions, and qualitative science. MPIs Clement, Kissinger, and Muzny collectively have decades of collaborative experience enrolling priority populations in large clinical trials aimed to improve sexual health outcomes. Ultimately, this trial has the potential to have substantial public health impact, leading to a novel bacterial STI prevention intervention to reduce the undue burden of incident bacterial STIs among women.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention | Experimental | Drug: Doxycycline200 mg oral doxy PEP (N=346) |
| Control | Active comparator | Other: Standard of Care (SOC)Standard of care (i.e. no doxy PEP, N=173) |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Female
- Aged 18-35
- Reporting condomless vaginal sex with men AND least one of the following:
- Plan to continue to be sexually active over the next year
- Have smartphone and be willing to engage with an app
Key exclusion criteria (7 listed)
- Pregnant, nursing, or intending to become pregnant
- Reported allergy to tetracyclines
- Liver disease or end-stage renal disease
- Non-English Speaking
- Taking concomitant medications which may impact doxycycline metabolism (e.g., systemic retinoids, antacids, barbiturates, carbamazepine, phenytoin, iron, warfarin, rifampin)
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 |
|---|---|---|
| DoxycyclineAlso: Doxy PEPEnrolled participants will be randomized 2:1 to receive 200 mg of doxy PEP taken within 24 hours of condomless sex versus standard of care. Only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result. | Drug | Intervention |
| Standard of Care (SOC)Enrolled participants will be randomized 2:1 to receive 200 mg of doxy PEP taken within 24 hours of condomless sex versus standard of care. Only one trial of the use of doxy PEP (dPEP Kenya) has been conducted among women, and unfortunately this study had a null result. | Other | Control |
Primary outcome
chlamydia incidence
Time frame: Participants will be evaluated at baseline and quarterly for 48 weeks with STI testing at each visit.
The primary outcome will be the number of CT infections over person-time (incidence rate).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jul 2026.
- Individual participant dataSharing planned: Yes. STI lab tests results, surveys results from baseline and quarterly visits, app data, doxycycline drug levels by urinalysis, doxycycline hair levels
Related trials for Chlamydia Females
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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.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Doxycycline in people with Chlamydia Females and Gonorrhea Female, run by Tulane University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 7 exclusion criteria. 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: opening soon, as of the sponsor's last update on 15 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. 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?
This study is still under way. Results are not available in the source record yet.
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?
chlamydia incidence (time frame: Participants will be evaluated at baseline and quarterly for 48 weeks with STI testing at each visit.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 15 Jul 2026.