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Linezolid for Syphilis Pilot Study

Pilot Study of Linezolid for Early Syphilis Treatment

Status
Active, not recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05548426
Enrollment
24
Registered
2022-09-21
Start date
2023-09-28
Completion date
2026-08-01
Last updated
2026-03-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Syphilis

Keywords

Linezolid, Treponema pallidum, Penicillin, Early Syphilis

Brief summary

The study aims to evaluate the efficacy of linezolid for the treatment of syphilis.

Detailed description

This will be a randomized, open-label, non-comparative, pilot trial to evaluate the efficacy of linezolid 600mg orally, twice a day, for ten days, using a contemporaneous historical control group benzathine penicillin G (single dose of 2.4 million units) in participants with and without HIV infection. In total, 24 participants will be enrolled across multiple clinical sites in the United States. Participants will participate in follow-ups to monitor clinical outcomes and serological response (RPR titer) at 1 month, 3 months, and 6 months. A 5 and 10-day phone call will ensure adherence to treatment and evaluate safety. Study findings may identify an efficacious alternative syphilis treatment to penicillin that is effective for people living with HIV. Study findings may also help address the crisis of penicillin shortages, difficulty in administration, and offer options for those with penicillin allergy.

Interventions

DRUGGroup B, Linezolid 10d

Oral Linezolid 600mg, taken twice a day for 10 days

DRUGGroup A, Penicillin

Standard of care benzathine penicillin G, one intramuscular injection, 2.4MU

Sponsors

University of Southern California
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
16 Years to No maximum
Healthy volunteers
No

Inclusion criteria

To be eligible for this study, participants must be: 1. Diagnosed cases of primary, secondary or early latent syphilis with RPR titer ≥1:8 within 3 weeks prior to enrollment 2. 16 years of age or older 3. Able to provide informed consent/assent. 4. Individuals with HIV infection must be on treatment for HIV-infection and virologically suppressed (viral load \< 200 copies/mL) or have a CD4 count ≥ 350 cells/mm3 as of their most recent test prior to enrollment.

Exclusion criteria

include: 1. Pregnancy or a positive pregnancy test on the day of enrollment 2. Patients showing signs and symptoms of neurosyphilis. 3. Participants who receive certain psychotropic medications, e.g., MAO inhibitors, SNRIs, SSRIs 4. Serofast RPR titer, defined as persistently positive RPR titer without more than 4-fold (2-titer level) change for 12 months or greater. 5. Recent (within the past 7 days) or concomitant antimicrobial therapy with activity against syphilis, namely azithromycin, tetracycline, doxycycline, cefixime, ceftriaxone or other beta lactam antibiotics (e.g. amoxicillin) 6. Individuals with HIV infection who report HIV treatment interruption for more than 4 weeks since their most recent viral load or CD4 test. 7. Individuals with known myelosuppressive conditions or receiving myelosuppressive medication 8. Individuals weighing 150kg (330 lbs) or more. 9. Individuals with known end renal stage disease, for example individuals in hemodialysis. 10. Self-reported allergy to linezolid or penicillin. 11. Unwilling or unable to attend follow-up visits.

Design outcomes

Primary

MeasureTime frameDescription
Response to Treatment6 monthsPercentage of linezolid participants with a 4-fold decrease or greater in the serum RPR titer by 180 days after treatment

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORJeffrey D Klausner, MD MPH

University of Southern California

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 13, 2026