Daily Doxycycline for Early Syphillis (NCT06683638) | Clinical Trial Compass
RecruitingPhase 2
Daily Doxycycline for Early Syphillis
United States15 participantsStarted 2025-03-03
Plain-language 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.
Who can participate
Age range18 Years
SexALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
â. Clinical diagnosis of primary syphilis (based on the presence of a chancre) and either a positive qualitative RPR in the absence of a prior positive RPR on their most recent serological test for syphilis or a positive darkfield microscope exam of material taken from a chancre, OR
â. Clinical diagnosis of secondary syphilis with a positive qualitative RPR in the absence of a prior positive RPR on their most recent serological test for syphilis, OR
â. A laboratory-confirmed diagnosis of early latent syphilis within one month (i.e. \<31 days prior).
Exclusion criteria
â. age under 18
â. persons with evidence of neurosyphilis (including ocular and otic syphilis) or tertiary syphilis
â. persons who are unable to give informed consent
â. persons deemed by the study investigators to be unable to complete study follow-up visits
â. persons with HIV who report that they are off antiretroviral medication or that they are not virologically suppressed
â. persons with other known forms of immunosuppression (e.g., persons taking systemic immunosuppressant drugs, persons with primary immunodeficiencies)