Sexually Transmitted Infection
Conditions
Brief summary
The goal of this project is to collect data regarding the concentrations of doxycycline in mucosal tissues after daily dosing for 7 days in people assigned male sex at birth (AMAB) and assigned female sex at birth (AFAB) to inform future studies of doxycycline to protect against bacterial sexually transmitted infections (STIs).
Detailed description
Recent studies have demonstrated the potential utility of single-dose oral doxycycline postexposure prophylaxis (Doxy-PEP) against bacterial sexually transmitted infections (STIs). Additional dosing strategies are being explored that would also provide protection from bacterial STIs. However, the pharmacokinetics of daily doxycycline and specifically the effect of this dosing on effective drug levels in mucosal tissues is underexplored. A previous pilot study conducted by the Division of human immunodeficiency virus (HIV) Prevention (DHP) Laboratory Branch at the Centers for Disease Control and Prevention (CDC) examined the ability of a single 100mg oral dose of doxycycline to penetrate the vaginal and rectal mucosa. However, data regarding daily doxycycline doses and accumulation of doxycycline with multiple doses are lacking. The purpose of this project is to collect data regarding the ability of daily oral doxycycline taken for 7 days to concentrate in mucosal tissues in people assigned male sex at birth (AMAB) and assigned female sex at birth (AFAB). Results from this study will be compared to results of the previous pilot studies conducted by the DHP Laboratory Branch at CDC. Healthy people assigned male or female sex at birth will take the first dose of doxycycline during the enrollment visit (Hour -144/Day -6) then will take the next 5 doses at home, one per day for the next 5 days. After 6 consecutive days of dosing, study participants will have samples collected (Hour 0/Day 0) and then will take the final dose. Rectal and vaginal swab samples will be obtained 2 to 4 hours after the final dose of doxycycline. Rectal and vaginal biopsy tissue will be collected 24 hours after the last dose.
Interventions
DRUGDoxycycline
Doxycycline (DOX) will be given orally at 100mg doses. Participants will take the study medication for 7 consecutive days.
Sponsors
Emory University
Centers for Disease Control and Prevention
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
This study aims to enroll a minimum of 10 AFAB and 10 AMAB participants.
Eligibility
Sex/Gender
ALL
Age
18 Years to 59 Years
Healthy volunteers
Yes
Inclusion criteria
* 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 cluster of differentiation 4 (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 prior to 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 course of 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: * Hemoglobin (Hgb) ≤ 10 g/dL * Partial thromboplastin time (PTT) \> 1.5x upper limit of normal (ULN) or international normalised ratio (INR) \> 1.5x ULN * Platelet count \<100,000
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Doxycycline Concentration in Rectal Tissue | 24 hours after last dose (Hour 24/Day 1) | Rectal tissue doxycycline concentrations collected 24 hours after 7 daily (T7) doses of 100 mg of doxycycline were determined in assigned male sex at birth (AMAB) participants. |
| Doxycycline Concentration in Vaginal Tissue | 24 hours after last dose (Hour 24/Day 1) | Vaginal tissue doxycycline concentrations collected 24 hours after 7 daily (T7) doses of 100 mg of doxycycline were determined in Assigned female sex at birth (AFAB) participants. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORColleen Kelley, MD, MPH
Emory University
Participant flow
Recruitment details
Participants were recruited from the Hope Clinic in Atlanta, Georgia, USA. Participant enrollment began September 13, 2024, and all follow up was completed by April 29, 2025.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 24 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 3 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 21 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 17 Participants |
| Race (NIH/OMB) More than one race | 3 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 3 Participants |
| Region of Enrollment United States | 24 Participants |
| Sex: Female, Male Female | 11 Participants |
| Sex: Female, Male Male | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 24 |
| other Total, other adverse events | 0 / 24 |
| serious Total, serious adverse events | 0 / 24 |
Outcome results
None listed