Trial Outcomes & Findings for Treatment Responses of Early Syphilis to Ceftriaxone Plus Doxycycline (NCT NCT05980871)
NCT ID: NCT05980871
Last Updated: 2026-02-25
Results Overview
Serologic response is defined as either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive
Recruitment status
TERMINATED
Study phase
PHASE4
Target enrollment
109 participants
Primary outcome timeframe
Month 6
Results posted on
2026-02-25
Participant Flow
Recruitment started from March 10, 2023, to August 16, 2024. Participants were recruited from infectious diseases clinics at the National Taiwan University Hopsital, Taiwan.
Participant milestones
| Measure |
CRO/Doxy
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
BPG/Doxy
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
|---|---|---|
|
Overall Study
STARTED
|
56
|
53
|
|
Overall Study
COMPLETED
|
56
|
53
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Treatment Responses of Early Syphilis to Ceftriaxone Plus Doxycycline
Baseline characteristics by cohort
| Measure |
CRO/Doxy
n=56 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
BPG/Doxy
n=53 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
Total
n=109 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
38 years
n=24 Participants
|
40 years
n=20 Participants
|
39 years
n=40 Participants
|
|
Sex: Female, Male
Female
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Sex: Female, Male
Male
|
56 Participants
n=24 Participants
|
53 Participants
n=20 Participants
|
109 Participants
n=40 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Asian
|
56 Participants
n=24 Participants
|
53 Participants
n=20 Participants
|
109 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
White
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=24 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Receiving ART at baseline
|
56 Participants
n=24 Participants
|
52 Participants
n=20 Participants
|
108 Participants
n=40 Participants
|
|
CD4 count at baseline
|
556 cells/mm^3
n=24 Participants
|
565 cells/mm^3
n=20 Participants
|
558 cells/mm^3
n=40 Participants
|
PRIMARY outcome
Timeframe: Month 6Serologic response is defined as either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive
Outcome measures
| Measure |
BPG/Doxy
n=53 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
CRO/Doxy
n=56 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
|---|---|---|
|
Rate of Serologic Response at Month 6
|
40 Participants
|
34 Participants
|
SECONDARY outcome
Timeframe: Week 4Population: Only participants with a positive Treponema pallidum PCR at baseline were included in this analysis.
Microbiologic response of syphilis is defined as T. pallidum PCR Ct value \>38
Outcome measures
| Measure |
BPG/Doxy
n=21 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
CRO/Doxy
n=18 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
|---|---|---|
|
Rate of Microbiologic Response of Syphilis at Week 4
|
20 Participants
|
17 Participants
|
SECONDARY outcome
Timeframe: Week 4Population: Only participants with detectable DNA of bacterial sexually transmitted infections at baseline were included in this analysis.
Microbiologic response of bacterial STIs is defined as negative PCR results
Outcome measures
| Measure |
BPG/Doxy
n=15 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
CRO/Doxy
n=19 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
|---|---|---|
|
Rate of Microbiologic Response of Bacterial STIs at Week 4
|
13 Participants
|
16 Participants
|
SECONDARY outcome
Timeframe: Month 3Serologic response is defined as either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive
Outcome measures
| Measure |
BPG/Doxy
n=53 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
CRO/Doxy
n=56 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
|---|---|---|
|
Rate of Serologic Response at Month 3
|
31 Participants
|
32 Participants
|
SECONDARY outcome
Timeframe: Month 12Serologic response is defined as either a 4-fold or greater decline in RPR titer compared to baseline or being RPR-nonreactive
Outcome measures
| Measure |
BPG/Doxy
n=53 Participants
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
CRO/Doxy
n=56 Participants
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
|---|---|---|
|
Rate of Serologic Response at Month 12
|
38 Participants
|
39 Participants
|
Adverse Events
CRO/Doxy
Serious events: 0 serious events
Other events: 26 other events
Deaths: 0 deaths
BPG/Doxy
Serious events: 0 serious events
Other events: 15 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
CRO/Doxy
n=56 participants at risk
a single intramuscular dose of 1.0 g ceftriaxone (CRO) combined with doxycycline (Doxy) 100 mg twice daily for 7 days
|
BPG/Doxy
n=53 participants at risk
a single intramuscular dose of 2.4 million units (MU) of BPG combined with Doxy 100 mg twice daily for 7 days
|
|---|---|---|
|
Musculoskeletal and connective tissue disorders
Myalgia
|
0.00%
0/56 • from treatment to 1 week after treatment
|
1.9%
1/53 • from treatment to 1 week after treatment
|
|
Skin and subcutaneous tissue disorders
Injection site pain or local swelling
|
42.9%
24/56 • from treatment to 1 week after treatment
|
20.8%
11/53 • from treatment to 1 week after treatment
|
|
Immune system disorders
Jarisch-Herxheimer reaction
|
17.9%
10/56 • from treatment to 1 week after treatment
|
3.8%
2/53 • from treatment to 1 week after treatment
|
|
Gastrointestinal disorders
Diarrhea
|
3.6%
2/56 • from treatment to 1 week after treatment
|
1.9%
1/53 • from treatment to 1 week after treatment
|
Additional Information
Tzong-Yow Wu
National Taiwan University Hospital Yunlin Branch
Phone: 886-933594074
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place