Daily Doxycycline for Early Syphillis

Part of paid clinical trials in Seattle, Washington.

Sponsor
University of Washington
Study ID
NCT06683638
Phase
PHASE2
Status
Recruiting
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Conditions

  • Syphilis

Eligibility Criteria

Sex
ALL
Age
18 Years - N/A
Healthy Volunteers
Not accepted

Interventions

  • Doxycycline 200mg daily for 14 days — DRUG
    Doxycycline will be taken as a single dose of 200mg daily, rather than the current CDC-recommended 100mg twice daily regimen for early syphilis. The duration will still be 14 days of therapy.

Study Details

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.

Key Dates

Start date
Mar 3, 2025
Status verified
Jun 2025
Primary completion
Jun 26, 2026
Completion
Jun 26, 2026

Study Design

Enrollment
15 participants (estimated)
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT

Arms

  • Experimental: Doxycycline 200mg daily for 14 days
    Participants diagnosed with early syphilis (primary, secondary, or early latent) with an RPR of 1:4 or greater will receive doxycycline 200mg daily to treat syphilis. Exclusions include pregnant persons, persons under 18 years of age, and persons on doxy PEP. During the two weeks of treatment, participants will perform oral and rectal swabs for syphilis, returned at the end of the 2 weeks by mail. Participants will submit brief online surveys twice over the two weeks of treatment. Repeat blood tests for syphilis, reactive plasma reagin (RPR), will be done at follow-up visits at 3 and 6 months to monitor serological response. Participants with response at the 3-month visit will not need to come to a 6-month visit.

Primary Outcome Measure

Composite clinical and serological response [ Time Frame: 6 months ]

Central Contacts

Locations (1)

FacilityCityStateZIPSite coordinators
Public Health Sexual Health ClinicSeattleWashington98104
Jakar Delacruz
[email protected]
206-744-3590
Travis Hunt, MD
[email protected]
206.685.4456
Travis J Hunt, MD (PRINCIPAL_INVESTIGATOR)
Matthew R Golden, MD, MPH (PRINCIPAL_INVESTIGATOR)

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