Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06069141

Comparisons of Treatment Responses of Early Syphilis to Benzathine Penicillin G With or Without Doxycycline

This randomized controlled superiority study will be conducted during 2023-2025. The eligible participants are adult people living with HIV (PLWH) who are newly diagnosed with early syphilis. Participants will be randomized in a 1:1 ratio to receive single-dose benzathine penicillin G (BPG) (2.4 MU intramuscularly once) plus doxycycline (100 mg orally twice daily for 7 days) or single-dose BPG. The primary outcome is serologic response, defined as a decline of rapid plasma reagin (RPR) titer by 4-fold or greater, at week 24 and week 48; and the secondary outcomes include microbiologic response of syphilis and bacterial sexually transmitted infections (STIs) assessed by nucleic-acid amplification test (NAAT) at week 4.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Early Syphilis, Latent, Serological Relapse After Treatment Bacterial Infections Bacterial Infections and Mycoses Communicable Diseases Genital Diseases Gram-Negative Bacterial Infections Infections Sexually Transmitted Diseases Sexually Transmitted Diseases, Bacterial Spirochaetales Infections Syphilis Treponemal Infections Urogenital Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • People living with HIV (PLWH) aged ≥18 years with early syphilis
  • Confirmed by a positive RPR titer with a reactive TPPA assay

Exclusion criteria

  • PWH with RPR titers of <4
  • Exposure to antibiotics with activity against T. pallidum within the preceding 4 weeks (penicillin, 3rd cephalosporin, doxycycline, macrolides)
  • A known or suspected infection requiring additional treatment with an antimicrobial active against T. pallidum (penicillin, 3rd cephalosporin, doxycycline, macrolides)
  • Testing positive for C. trachomatis and M. genitalium, for which doxycycline or macrolide was administered
  • A history of intolerance to penicillin or doxycycline
  • PLWH have already participated in this study
  • Pregnancy

Treatment and study plan

Benzathine Penicillin G

Drug

Benzathine Penicillin G (2.4 MU intramuscularly once)

Doxycycline Capsule

Drug

doxycycline (100 mg orally twice daily for 7 days)

Primary outcomes

  1. Serologic response

    Time frame: Weeks 24 and week 48

    Either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive

Secondary outcomes

  1. Microbiologic response of syphilis

    Time frame: Week 4

    T. pallidum PCR Ct value >38

  2. Microbiologic response of bacterial STIs

    Time frame: Week 4

    negative STI PCR results

  3. Safety of study treatment

    Time frame: Week 4

  4. Adherence evaluation of tablet intake

    Time frame: Week 4

Study contacts

Contact information is provided by the study sponsor or research team.

Kuan-Yin Lin, MD

CONTACT

[email protected]

+886-975607715

Sponsors and collaborators

Lead sponsor

National Taiwan University Hospital

Other

Collaborators

  • Chi Mei Medical Hospital
  • Far Eastern Memorial Hospital
  • Kaohsiung Medical University Chung-Ho Memorial Hospital
  • Kaohsiung Veterans General Hospital.
  • National Cheng-Kung University Hospital
  • National Taiwan University Hospital Hsin-Chu Branch
  • Taipei Veterans General Hospital, Taiwan
  • Taoyuan General Hospital

Registry information

Official study title

Comparisons of Treatment Responses of Early Syphilis to 2.4 Milliunits (MU) Single-dose Benzathine Penicillin G With or Without Doxycycline in People Living With HIV

Important dates

Study start
2024
Primary completion
2027
Study completion
2028
First posted
Oct 5, 2023
Registry last updated
Nov 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.