Phase 4 N=45 Randomized Prevention

Doxy-Post-exposure Prophylaxis

Sexually Transmitted Diseases

Bottom Line

View on ClinicalTrials.gov: NCT05853120 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Sep 2025

Primary outcome: Primary: Doxycycline Concentrations in Rectal Tissues — 0.863; 2.193 µg/g

Study Design & Population

Study type: Interventional
Phase: Phase 4
Interventions: Doxycycline (Drug)
Age: Adult · 18+ yrs
Sex: All
Sponsor: Emory University
Primary completion: Sep 2024

Outcome Measures

Outcome	Result	p-value
PRIMARY Doxycycline Concentrations in Rectal Tissues	0.863; 2.193	—
PRIMARY Doxycycline Concentrations in Vaginal Tissues	0.592; 1.214	—
PRIMARY Doxycycline Concentrations in Rectal Tissues After the Fifth Dose of Doxycycline	0.951; 1.612	—
PRIMARY Doxycycline Concentrations in Vaginal Tissues Collected 24 Hours After the Fifth Dose of Doxycycline	0.590; 1.534	—

Summary

The goal of this project is to collect data regarding the ability of various oral doses of doxycycline to penetrate mucosal tissues in men and women to inform the combination of doxycycline with antiretrovirals (ARVs) for the development of single-dose event-driven multipurpose prevention strategies to protect against HIV and sexually transmitted infections (STIs). This study is of importance in the field of research because it allows the exploration of new dosing strategies that would permit a single event-driven oral dose of medications that could provide protection from HIV as well as other STIs. The study population that this study seeks to enroll are healthy people assigned male or female sex at birth and not using gender-affirming hormone therapy and are willing to undergo study procedures. Recruitment: Both face-to-face and online engagements will be conducted to recruit study participants. Face-to-face locations include bars and nightclubs, community organizations serving study populations, sports events, and community venues, and online engagements include dating sites, social networks, and craigslist, amongst other social medial platforms.

Eligibility Criteria

Inclusion Criteria

Aged 18-59 years
Assigned male sex or female sex at birth
In good general health
Not currently taking doxycycline or other tetracycline-derived antibiotics and no plans to initiate during the study
For HIV-positive people, on stable antiretroviral therapy with an undetectable viral load and CD4 count> 300ul/ml
Willing to use condoms consistently for the duration of the study
Able to provide informed consent
No plans for relocation in the next 4 months
Not pregnant and does not plan on getting pregnant for the duration of the study
Willing to undergo peripheral blood, urine, rectal or vaginal secretion collection, and a rectal or vaginal and cervical biopsy procedure
Willing to use study products as directed

Exclusion Criteria

Current or chronic history of liver disease
Continued need for, or use during the 90 days before enrollment, of the following medications:
Systemic immunomodulatory agents
Supraphysiologic doses of steroids (short course steroids less than 7 days duration, allowable at the discretion of the investigators)
Chemotherapy or radiation for treatment of malignancy
Experimental medications, vaccines, or biologicals
Intent to use doxycycline or other tetracycline-derived antibiotics during the study, outside of the study procedures
Any other clinical condition or prior therapy that, in the opinion of the investigator, would make the patient unsuitable for the study or unable to comply with the study requirements
Known allergic reaction to study drugs.
Significant laboratory abnormalities at baseline visit for rectal biopsies, including but not limited to:
Hgb ≤ 10 g/dL
PTT > 1.5x ULN or INR > 1.5x ULN
Platelet count <100,000

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT05853120). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.