Trial Outcomes & Findings for Daily Doxycycline to Inform Sexually Transmitted Infection Prophylaxis Regimens (NCT NCT06545656)
NCT ID: NCT06545656
Last Updated: 2026-05-01
Results Overview
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.
COMPLETED
PHASE4
24 participants
24 hours after last dose (Hour 24/Day 1)
2026-05-01
Participant Flow
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.
Participant milestones
| Measure |
Doxycycline
Study participants took 7 consecutive, daily doses of 100mg of Doxycycline.
Doxycycline: Doxycycline (DOX) was administered orally at a dose of 100mg. Participants took the study medication for 7 consecutive days.
|
|---|---|
|
Overall Study
STARTED
|
24
|
|
Overall Study
COMPLETED
|
23
|
|
Overall Study
NOT COMPLETED
|
1
|
Reasons for withdrawal
| Measure |
Doxycycline
Study participants took 7 consecutive, daily doses of 100mg of Doxycycline.
Doxycycline: Doxycycline (DOX) was administered orally at a dose of 100mg. Participants took the study medication for 7 consecutive days.
|
|---|---|
|
Overall Study
Lost to Follow-up
|
1
|
Baseline Characteristics
Daily Doxycycline to Inform Sexually Transmitted Infection Prophylaxis Regimens
Baseline characteristics by cohort
| Measure |
Doxycycline
n=24 Participants
Study participants took 7 consecutive, daily doses of 100mg of Doxycycline.
Doxycycline: Doxycycline (DOX) was administered orally at a dose of 100mg. Participants took the study medication for 7 consecutive days.
|
|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=14 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
24 Participants
n=14 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=14 Participants
|
|
Sex: Female, Male
Female
|
11 Participants
n=14 Participants
|
|
Sex: Female, Male
Male
|
13 Participants
n=14 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
3 Participants
n=14 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
21 Participants
n=14 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=14 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=14 Participants
|
|
Race (NIH/OMB)
Asian
|
1 Participants
n=14 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=14 Participants
|
|
Race (NIH/OMB)
Black or African American
|
17 Participants
n=14 Participants
|
|
Race (NIH/OMB)
White
|
3 Participants
n=14 Participants
|
|
Race (NIH/OMB)
More than one race
|
3 Participants
n=14 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=14 Participants
|
|
Region of Enrollment
United States
|
24 Participants
n=14 Participants
|
PRIMARY outcome
Timeframe: 24 hours after last dose (Hour 24/Day 1)Population: Only 10 AMAB participants completed the mucosal sampling visit #8, where primary outcome 1 was assessed.
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.
Outcome measures
| Measure |
Doxycycline
n=10 Participants
Study participants took 7 consecutive, daily doses of 100mg of Doxycycline.
Doxycycline: Doxycycline (DOX) was administered orally at a dose of 100mg. Participants took the study medication for 7 consecutive days.
|
|---|---|
|
Doxycycline Concentration in Rectal Tissue
|
2.330 µg/g
Interval 0.92 to 6.54
|
PRIMARY outcome
Timeframe: 24 hours after last dose (Hour 24/Day 1)Population: Only 9 AFAB participants completed the mucosal sampling visit #8, where Primary Outcome 2 was assessed
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.
Outcome measures
| Measure |
Doxycycline
n=9 Participants
Study participants took 7 consecutive, daily doses of 100mg of Doxycycline.
Doxycycline: Doxycycline (DOX) was administered orally at a dose of 100mg. Participants took the study medication for 7 consecutive days.
|
|---|---|
|
Doxycycline Concentration in Vaginal Tissue
|
1.320 µg/g
Interval 0.77 to 2.09
|
Adverse Events
Doxycycline
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place