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Not yet recruitingNCT07884240Updated Oct 20, 2026

A Clinical Study to Assess the Efficacy of Weekly Doxycycline Prophylaxis to Reduce Bacterial Sexually Transmitted Infections (STI) in Young African Women

A Phase 3 interventional study of Doxycycline hyclate and Standard of Care for STI prevention in Sexually Transmitted Infection (STI), Gonorrhea and Syphilis, sponsored by National Institute of Allergy and Infectious Diseases (NIAID). Not yet recruiting at 4 sites in 4 countries. Open to female participants aged 13 Years to 34 Years. Per ClinicalTrials.gov, last updated 2026-10-20.

Sponsored by National Institute of Allergy and Infectious Diseases (NIAID) · Phase 3, Interventional, and Prevention

Updated Oct 20, 2026Newly registeredGo to Updates ↓
Phase
Phase 3
Study type
Interventional
Enrollment
580
Allocation
Randomized
Ages
13 Years to 34 Years
Sex
Female
01

Study summary

This study is for people who may get sexually transmitted infections (STIs). Approximately 580 African adolescent and young adult women ages 13-34 in Africa will be included in this study. Study participation is approximately 52 weeks (1 year). Participants will be randomized in a 1:1 ratio to receive doxycycline prophylaxis or standard of care.

02

Conditions studied

  • Sexually Transmitted Infection (STI)
  • Gonorrhea
  • Syphilis
  • Chlamydia

Keywords

  • Sexually transmitted infection (STI)
  • Gonorrhea
  • Chlamydia
  • Adolescent
  • Adult
  • Early Syphilis
  • Women
  • Africa
03

In context

Sexually Transmitted Diseases

435 studies on the registry are indexed under Sexually Transmitted Diseases; 73 are open to participants now.

This study's planned enrollment of 580 is above the median of 460 across 356 interventional studies indexed under Sexually Transmitted Diseases.

Browse Sexually Transmitted Diseases studies →

Lead sponsor

National Institute of Allergy and Infectious Diseases (NIAID) is the lead sponsor of 2,445 studies on the registry; 182 are open to participants now.

Of its 402 completed or terminated interventional studies of FDA-regulated products, 300 (75%) have results posted.

Browse National Institute of Allergy and Infectious Diseases (NIAID) studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
13 Years to 34 Years
Sexes eligible
Female
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

All adolescent and adult young women who meet all the following criteria are eligible for inclusion in this study:

  • Age 13-34 years, inclusive.

  • In good health as determined by past medical history, medication use, and targeted physical examination,

    • If not living with HIV, negative HIV test conducted at screening
    • If living with HIV, on an antiretroviral regimen for ≥3 months

  • Report at least two of the following:

    • Treatment for a curable STI (not including HIV) in the past 12 months prior to screening.
    • Self-report of condomless (oral, vaginal, and/or anal) intercourse at least once in the 30 days prior to screening
    • Has had two or more partners in the past 6 months
  • ≥ 45 kilograms (99 pounds) in weight
  • Anticipate living in the study area for 12 months and no plans for travel away from the study site for a time period that would interfere with product resupply and study participation
  • Willing to undergo all required study procedures that may include Directly/Video observed therapy (D/VOT); and

  • Provide written informed consent to participate in the study

    • If of legal age or otherwise able to provide independent informed consent as determined by local law and consistent with Institutional Review Board (IRB)/Ethics Committee (EC) policies: Willing and able to provide written informed consent for study participation.
    • If not of legal age or otherwise not able to provide independent informed consent as determined by local law and consistent with IRB/EC policies: Parent or legal guardian is willing and able to provide written informed consent for study participation and potential participant is willing and able to provide written assent for study participation.

Exclusion criteria

Exclusion Criteria:

All adolescent and adult young women who meet any of the following criteria will be excluded from this study:

  • Is male.
  • Positive NAAT for CT or NG or with evidence of untreated syphilis infection.
  • Documented history of tetracycline allergy or self-reports an allergy to tetracyclines.
  • Current (within 30 days of Enrollment) or anticipated use of a medication with a contraindicated interaction to doxycycline (e.g., iron, barbiturates, phenytoin, lithium, carbamazepine, systemic retinoids, warfarin).
  • Current or planned use of doxycycline for a prolonged period (> 2 weeks) in the 30 days prior to enrollment, including current prescription for doxycycline for STI prophylaxis.
  • Prolonged antibiotic use (> 2 weeks) within the last 30 days prior to enrollment.
  • Pregnant, or breastfeeding.
  • Co-enrollment in any other concurrent interventional research or studies that may interfere with this study, unless approved by the Protocol Team in writing.
  • Any other medical condition, medical/behavioral intervention, or other conditions that, in the opinion of the clinical site Principal Investigator/Investigator of Record (PI/IoR) or designee, could interfere with adherence to study procedures or compromise interpretation of study results.
05

Study design

Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
580 participants (estimated)

Study arms

  • Experimental
    Doxycycline hyclate 200 mg

    Participants randomized to the intervention arm will receive doxycycline hyclate 200 mg (2 x 100mg) administered orally once weekly, for the duration of 51 weeks.

    Drug: Doxycycline hyclate

  • Active comparator
    Standard of Care

    Participants randomized to the standard-of-care arm alone will not receive doxycycline prophylaxis and will receive local standard of care for STI prevention per local guidelines.

    Drug: Standard of Care for STI prevention

Interventions

  • DrugDoxycycline hyclate

    Two 100 mg doxycycline hyclate immediate-release (IR) tablets (total dose: 200 mg) administered orally once weekly. Weekly dosing for approximately 51 weeks.

  • DrugStandard of Care for STI prevention

    No study product. Participants receive local standard of care for STI prevention

06

What researchers measure

Primary outcomes

  1. The Rate of Composite Incident STI events

    Nucleic acid amplification test (NAAT) from all sites (vaginal, rectal, oropharyngeal) or newly positive or four-fold rise in RPR titers

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

Secondary outcomes

  1. The Rate of Incident Chlamydia Trachomatis (CT) Infection

    Nucleic Acid Amplification Test (NAAT) From All Sites (vaginal, rectal, oropharyngeal)

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

  2. The Rate of Incident Neisseria Gonorrhoeae (NG) Infection

    Nucleic Acid Amplification Test (NAAT) From All Sites (vaginal, rectal, oropharyngeal)

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

  3. The Rate of Incident Early Syphilis Infection

    Newly Positive or Four-Fold Rise in Rapid Plasma Reagin (RPR) Titers From All Sites (vaginal, rectal, oropharyngeal)

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

  4. The Rate of Incident NG Infection

    Nucleic Acid Amplification Test (NAAT) From Rectal or Pharyngeal Site

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

  5. The Rate of Incident CT Infection

    Nucleic Acid Amplification Test (NAAT) From Rectal or Pharyngeal Site

    Time frame: Testing will occur at each quarterly visit (week 13, 26, 39 and 52).

  6. The Number of Doxycycline-specific Side Effects

    Such as gastrointestinal upset, photosensitivity, esophageal irritation, and skin reactions

    Time frame: Week 0 through Week 52

  7. The Number of Participants who discontinue study due to side effects

    Time frame: Week 0 through Week 52

  8. Number of Participants with Serious Adverse Events (SAEs)

    Time frame: Week 0 through Week 52

  9. Number of Participants with Adverse Events (AEs)

    Time frame: Week 0 through Week 52

  10. Acceptability of Weekly Doxycycline Prophylaxis

    The acceptability Likert scale has the following response options: Very acceptable/ Somewhat acceptable/ Neither acceptable nor unacceptable/ Somewhat unacceptable/ Very unacceptable/ Prefer not to answer

    Time frame: Week 4, 13, 26, 39 and 52

  11. Adherence to Weekly Doxycycline Prophylaxis

    Number of directly observed doses

    Time frame: Up to 52 weeks.

  12. Number of Tetracycline-resistant isolates for CT

    Summarized by Randomized Study Arm

    Time frame: Week 0, Week 26 and Week 52.

  13. Number of Tetracycline-resistant isolates for NG

    Summarized by Randomized Study Arm

    Time frame: Week 0, Week 26 and Week 52.

  14. Number of Tetracycline resistant isolates of M. genitalium

    Summarized by Randomized Study Arm

    Time frame: Week 0, Week 26 and Week 52

  15. Number of Tetracycline resistant isolates of S. aureus

    Summarized by Randomized Study Arm

    Time frame: Week 0, Week 26 and Week 52.

07

Study locations

4 sites
  • Gaborone CRS (Site ID 12701)
    Gaborone, Botswana
  • Eswatini Prevention Center CRS (Site ID 31994)
    Mbabane, Eveni H103, Eswatini
  • Malawi CRS (Site ID 12001)
    Lilongwe, A-104, Malawi
  • MU-JHU Research Collaboration (MUJHU CARE LTD) CRS (Site ID 30293)
    Kampala, Uganda
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

1 registry update since Sep 25, 2026
Registered
First appeared on the registry. No changes since
Oct 20, 2026
Show all 1 update
  1. Oct 20, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07884240
Lead sponsor
National Institute of Allergy and Infectious Diseases (NIAID)
Responsible party
Sponsor
First posted
Oct 20, 2026
Start date
Nov 30, 2026 (estimated)
Primary completion
Sep 30, 2028 (estimated)
Completion
Jul 10, 2029 (estimated)
Last update
Oct 20, 2026

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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