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NCT06683638 · ClinicalTrials.gov registry record · Phase 2
Daily Doxycycline for Early Syphillis
A Phase 2 study of Syphilis, sponsored by University of Washington.
- Recruiting
- Registry status
- Phase 2
- Development phase
- 15
- Enrollment target
- 1
- Study location
NCT06683638: Recruiting Phase 2 study of Syphilis, sponsored by University of Washington.
NCT06683638 is a Phase 2 study of Syphilis that is actively recruiting participants, run by University of Washington. The registered enrollment target is 15 participants, below the 272-participant average among 6 other Syphilis trials with a reported enrollment target (94% lower). The trial reports 1 study location across 1 state. According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT06683638, a Phase 2 study of Syphilis, is actively recruiting participants, sponsored by University of Washington.
- RECRUITING
- Registry status
- Phase 2
- Development phase
- 15 participants
- Enrollment target
- 1
- Study location
Study Summary
The goal of this clinical trial is to learn if doxycycline taken as 200mg daily for 14 days is effective to treat early stage syphilis. This is different from how doxycycline is typically used for syphilis because the full doxycycline dose will be taken at the same time of day, rather than split up into a twice daily regimen. Lab data support that taking the medication as a single daily dose should be effective as treatment, but it has not been studied clinically. The main question this study aims to answer is: Is doxycycline taken as a single daily dose of 200mg for 14 days an effective treatment for early syphilis based on a combined outcome of clinical improvement and blood test improvement? Participants will: 1. Take doxycycline 200mg daily for 14 days 2. Submit oral and rectal swabs that test for syphilis bacteria every other day for 2 weeks, returned by mail 3. Complete 2 brief online surveys over the first 2 weeks 4. Return to the clinic for an interview and blood draw every 3 months for a maximum of 3 study visits, including the first visit The investigators will compare the percentage of participants in the study who have response to treatment by 6 months to that of persons who have received standard (CDC-recommended) regimens. To do this, the investigators will calculate response percentage estimates following a shot of long-acting penicillin or 14 days of doxycycline 100mg twice daily from 60-person samples from the sexual health program's records.
Primary Outcome
Clinical response and serological response will be aggregated to arrive at one reported value, a binary outcome of "yes" (1) or "no" (0). Clinical response equates to resolution of clinical symptoms of syphilis the participants presented with, such as rash or chancre, without the development of new symptoms of syphilis. Resolution will be marked as "yes" or "no". Serological response equates to a fourfold decrease in RPR compared to the presenting RPR titer by 6 months. Resolution will be mark
Conditions Studied
Interventions
- DRUG Doxycycline 200mg daily for 14 days
Study Locations (1)
Washington
- Public Health Sexual Health Clinic - Seattle
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 15 participants |
| Start Date | 2025-03-03 |
| Est. Completion | 2026-06-26 |
| Phase | Phase 2 |
What NCT06683638 shows while recruiting
NCT06683638 is an interventional study that assigns participants to a tested intervention. The registry caps enrollment at 15 participants, a relatively small participant target, below the 272-participant average among 6 other Syphilis trials with a reported enrollment target (94% lower).
The record links to 1 condition, with Syphilis appearing as the primary indexed condition, and to 1 intervention - of which Doxycycline 200mg daily for 14 days is the first listed.
NCT06683638 reports a single indexed study location in Washington.
Frequently Asked Questions
What is clinical trial NCT06683638 about?
NCT06683638 is a clinical study titled "Daily Doxycycline for Early Syphillis". The goal of this clinical trial is to learn if doxycycline taken as 200mg daily for 14 days is effective to treat early stage syphilis. This is different from how doxycycline is typically used for syphilis because the full doxycycline dose will be taken at the same time of day, rather than split up ...
What is the current status of trial NCT06683638?
This trial is currently recruiting. It is a Phase 2 study. The enrollment target is 15 participants. The study started on 2025-03-03. Estimated completion is 2026-06-26.
What conditions does trial NCT06683638 study?
This clinical trial studies the following conditions: Syphilis.
What interventions are being tested in trial NCT06683638?
The interventions under investigation include: Doxycycline 200mg daily for 14 days (DRUG).
Who is sponsoring clinical trial NCT06683638?
This trial is sponsored by University of Washington, which has 1,048 total clinical trials registered on ClinicalTrials.gov.
Where is trial NCT06683638 being conducted?
This trial has 1 study location across Washington. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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