An interventional study of Benzathine Penicillin G and Doxycycline Capsule in Early Syphilis, Latent, Serological Relapse After Treatment, sponsored by National Taiwan University Hospital. Recruiting at 9 sites in Taiwan. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by National Taiwan University Hospital · Not applicable, Interventional, and Treatment
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.
126 studies on the registry are indexed under Syphilis; 34 are open to participants now.
This study's planned enrollment of 688 is above the median of 354 across 85 interventional studies indexed under Syphilis.
Browse Syphilis studies →National Taiwan University Hospital is the lead sponsor of 2,615 studies on the registry; 576 are open to participants now.
Of its 11 completed or terminated interventional studies of FDA-regulated products, 2 (18%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
single-dose benzathine penicillin G (2.4 MU intramuscularly once) plus doxycycline (100 mg orally twice daily for 7 days)
Drug: Benzathine Penicillin G · Drug: Doxycycline Capsule
single-dose benzathine penicillin G (2.4 MU intramuscularly once)
Drug: Benzathine Penicillin G
Benzathine Penicillin G (2.4 MU intramuscularly once)
doxycycline (100 mg orally twice daily for 7 days)
Serologic response
Either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive
Time frame: Weeks 24 and week 48
Microbiologic response of syphilis
T. pallidum PCR Ct value \>38
Time frame: Week 4
Microbiologic response of bacterial STIs
negative STI PCR results
Time frame: Week 4
Safety of study treatment
Time frame: Week 4
Adherence evaluation of tablet intake
Time frame: Week 4
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Doxycycline
National Taiwan University Hospital →