Treatment Responses of Early Syphilis to Ceftriaxone Plus Doxycycline

NCT ID: NCT05980871

Last Updated: 2025-11-18

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 300 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-03-10
• Study Completion Date: 2026-01-31

Brief Summary

In a prospective study investigating the prevalence of STIs among at-risk PLWH, the prevalence of Chlamydia trachomatis and N. gonorrhoeae was 24.7% and 12.1%, respectively. Surprisingly, the study found high rates of C. trachomatis and/or N. gonorrhoeae co-infections in PLWH with recent hepatitis C virus (HCV) infection (50%), HBsAg positivity (44%), and early syphilis (36%). Considering the high rate of sexually transmitted co-infections, combination therapy of single-dose ceftriaxone plus 7-day doxycycline for early syphilis may provide convenience and benefit to treatment of N. gonorrhoeae and C. trachomatis co-infections at a single clinic encounter. In the present study, this study aim to compare the efficacy of ceftriaxone plus doxycycline versus BPG plus doxycycline as the treatment for early syphilis among PLWH.

Detailed Description

Enrolled criteria:

1. PLWH aged 20 years or more

2. PLWH with early syphilis (i.e. primary, secondary, or early latent syphilis), confirmed by a positive rapid plasma reagin (RPR) titer with a reactive Treponema pallidum particle agglutination (TPPA) assay.

3. PLWH has provided informed consent *A participant with repeated syphilis can be repeated enrolled after signing an informed consent if the previous episode of early syphilis was successfully treated with achieving at least a 4-fold decrease in RPR titers and 48-week follow-up is completed.

Exclusion criteria:

1. PLWH with RPR titers of less than 4

2. Exposure to antibiotics with activity against T. pallidum, such as penicillins, third-generation cephems, doxycycline, or macrolides, within the preceding 4 weeks

3. A known or suspected infection other than syphilis requiring additional treatment with an antimicrobial active against T. pallidum

4. A history of intolerance to penicillin, ceftriaxone, or doxycycline

5. Pregnancy

Primary outcome:

Serologic response at month 6 (defined as either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive)

Secondary outcomes:

1. Microbiologic response of syphilis (defined as T. pallidum PCR Ct value >38) at week 4

2. Microbiologic response of bacterial STIs (defined as negative PCR results) at week 4

3. Serologic response at months 3 and 12

4. Safety of study treatment recorded by using a diary (all adverse events will be coded and graded according to Common Terminology Criteria for Adverse Events [CTCAE] v4.0.)

5. Adherence evaluation (the noting of tablet intake in the diary for the 7 days of the treatment period)

Conditions

Early Syphilis

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

single-dose ceftriaxone plus doxycycline

single-dose ceftriaxone (1g intramuscularly once) plus doxycycline (100 mg orally twice daily for 7 days)

Group Type: ACTIVE_COMPARATOR

Doxycycline

Intervention Type: DRUG

doxycycline (100 mg orally twice daily for 7 days)

Ceftriaxone

Intervention Type: DRUG

Ceftriaxone (1g intramuscularly once)

single-dose BPG plus doxycycline

single-dose BPG (2.4 MU intramuscularly once) plus doxycycline (100 mg orally twice daily for 7 days)

Group Type: ACTIVE_COMPARATOR

Doxycycline

Intervention Type: DRUG

doxycycline (100 mg orally twice daily for 7 days)

benzathine penicillin G

Intervention Type: DRUG

benzathine penicillin G (2.4 MU intramuscularly once)

Interventions

Doxycycline

doxycycline (100 mg orally twice daily for 7 days)

Intervention Type: DRUG

Ceftriaxone

Ceftriaxone (1g intramuscularly once)

Intervention Type: DRUG

benzathine penicillin G

benzathine penicillin G (2.4 MU intramuscularly once)

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• PLWH aged 20 years or more
• PLWH with early syphilis (i.e. primary, secondary, or early latent syphilis), confirmed by a positive rapid plasma reagin (RPR) titer with a reactive Treponema pallidum particle agglutination (TPPA) assay.
• PLWH has provided informed consent

Exclusion Criteria

• PLWH with RPR titers of less than 4
• Exposure to antibiotics with activity against T. pallidum, such as penicillins, third- generation cephems, doxycycline, or macrolides, within the preceding 4 weeks
• A known or suspected infection other than syphilis requiring additional treatment with an antimicrobial active against T. pallidum
• A history of intolerance to penicillin, ceftriaxone, or doxycycline
• Pregnancy

• Minimum Eligible Age: 20 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Taiwan University Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Kuan-Yin Lin

Role: PRINCIPAL_INVESTIGATOR

National Taiwan University Hospital

Locations

Kuan-Yin Lin

Taipei, Taiwan, Taiwan

Site Status: RECRUITING

Countries

Taiwan

Central Contacts

Kuan-Yin Lin

Role: CONTACT

kuanyin0828@gmail.com

+886975607715

Facility Contacts

Kuan-Yin Lin

Role: primary

maregold@ntuh.gov.tw

+886975607715

Other Identifiers

202206138MIND

Identifier Type: -

Identifier Source: org_study_id