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Doxycycline Hyclate Delayed-Release 200 mg for Syphilis

Phase 4
Waitlist Available
Led By Anne Luetkemeyer, MD
Research Sponsored by University of California, San Francisco
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Be older than 18 years old
Timeline
Screening 3 weeks
Treatment Varies
Follow Up 1 year
Awards & highlights
Pivotal Trial
Drug Has Already Been Approved
No Placebo-Only Group

Summary

This trial is testing if taking a doxycycline pill after unprotected sex can prevent STIs like gonorrhea, chlamydia, and syphilis. The study focuses on men who have sex with men, including those with HIV and those on PrEP. Doxycycline works by killing or stopping the bacteria that cause these infections. Doxycycline has been used for the prevention of syphilis and other sexually transmitted infections, with studies showing high efficacy.

Eligible Conditions
  • Syphilis
  • Chlamydia
  • Gonorrhea

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~1 year
This trial's timeline: 3 weeks for screening, Varies for treatment, and 1 year for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Number of Quarterly Visits In Which an STI Was Detected

Awards & Highlights

Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.
Drug Has Already Been Approved
The FDA has already approved this drug, and is just seeking more data.
No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.

Trial Design

2Treatment groups
Experimental Treatment
Active Control
Group I: Doxy PEPExperimental Treatment1 Intervention
Doxycycline 200mg in addition to standard of care STI testing and treatment
Group II: ControlActive Control1 Intervention
The control arm will consist of standard of care STI testing and treatment
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Doxycycline Hyclate Delayed-Release 200 mg
2019
Completed Phase 4
~650

Find a Location

Who is running the clinical trial?

San Francisco Department of Public HealthOTHER_GOV
37 Previous Clinical Trials
35,403 Total Patients Enrolled
University of California, San FranciscoLead Sponsor
2,580 Previous Clinical Trials
15,176,859 Total Patients Enrolled
1 Trials studying Syphilis
449 Patients Enrolled for Syphilis
University of WashingtonOTHER
1,812 Previous Clinical Trials
1,913,160 Total Patients Enrolled
4 Trials studying Syphilis
3,630 Patients Enrolled for Syphilis
~108 spots leftby Nov 2025
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