Alternative Antibiotics for Syphilis

NCT ID: NCT05069974

Last Updated: 2025-07-22

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE3

Total Enrollment

224 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-10-14

Study Completion Date

2026-04-30

Brief Summary

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The Trep-AB clinical trial will test the efficacy of an investigational neuropenetrative drug, Linezolid (LZD), compared to standard treatment, Benzathine penicillin G (BPG), for early syphilis in humans. The overarching idea of the work proposed herein is to investigate the use of LZD to treat syphilis, conducting a randomized controlled clinical trial to evaluate this new indication of a known antibacterial agent.

Detailed Description

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The syphilis epidemic is rampant around the world, and therapeutic options are restricted to an antibiotic, intramuscular (IM) BPG, which does not efficiently cross the blood-brain barrier. Treponema pallidum (T.p.), the bacteria that causes syphilis, invades the central nervous system (CNS) in 40% of patients, usually without symptoms. The prognostic implications of CNS invasion are the potential for severe neurologic complications, and treatment failure due to sequestered bacteria in the CNS. When indicated, the only way to identify and treat neurosyphilis is by lumbar puncture to examine the cerebrospinal fluid (CSF), followed by intravenous (IV) Benzyl penicillin therapy. The invetigators have carried out in silico studies showing that oxazolidinones are potentially active against T.p., are neuropenetrative and can be administered orally. The invetigators have carried out preclinical studies using an in vitro culture system for T.p. and the use of the syphilis animal model with rabbits to test different antibiotics. The invetigators have confirmed that LZD was the best compound that could go on to be tested in clinical trials to treat syphilis.

The Trep-AB clinical trial will test the efficacy of an investigational neuropenetrative drug, LZD, compared to standard treatment BPG, for early syphilis in humans conducting a randomized controlled clinical. Primary objective is to demonstrate the non-inferiority of LZD treatment compared with standard BPG treatment to cure patients with early syphilis. Seconday objective is to isolate T.p. strains in clinical samples to subtype DNA from patients at baseline and during recurrence or treatment failure.

Conditions

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Early Latent Syphilis Primary Syphilis Secondary Syphilis

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Open-label, non inferiority, randomized clinical trial. Eligible patients will be randomized to recieve Linezolid (experimental arm) or BPG (control arm).
Primary Study Purpose

TREATMENT

Blinding Strategy

SINGLE

Outcome Assessors
The statistical analysis will be blinded.

Study Groups

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Linezolid (LZD) 1200

Patients will take film coated tables of LZD 600 mg every 12 hours during 10 days

Group Type EXPERIMENTAL

Linezolid 600 mg

Intervention Type DRUG

After randomized to the experimental arm, the patient will take 1 tablet of Linezolid every 12hours during 10 days or 1 tablet of of Linezolid every 24hours during 5 days.

Benzathine Penicillin G (BPG)

Administration of intramuscular BPG 2.4 MIU single dose during day 1

Group Type ACTIVE_COMPARATOR

Benzathine Penicilllin G

Intervention Type DRUG

After randomized to the control arm, the patient will receive a single dose of intramuscular BPG.

Linezolid (LZD) 600

Patients will take film coated tables of LZD 600 mg every 24 hours during 5 days

Group Type EXPERIMENTAL

Linezolid 600 mg

Intervention Type DRUG

After randomized to the experimental arm, the patient will take 1 tablet of Linezolid every 12hours during 10 days or 1 tablet of of Linezolid every 24hours during 5 days.

Interventions

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Linezolid 600 mg

After randomized to the experimental arm, the patient will take 1 tablet of Linezolid every 12hours during 10 days or 1 tablet of of Linezolid every 24hours during 5 days.

Intervention Type DRUG

Benzathine Penicilllin G

After randomized to the control arm, the patient will receive a single dose of intramuscular BPG.

Intervention Type DRUG

Eligibility Criteria

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Inclusion Criteria

1. Age 18 years or older at baseline visit.
2. Primary, secondary or early latent syphilis diagnosis based on SEIMC/IUSTI Guidelines\*

1. Primary syphilis is defined as typical ulcer (chancre) and positive test using darkfield examination (DFE) or Polymerase chain reaction (PCR) detection of T.p. with/without positive serological test for syphilis.
2. Secondary syphilis is defined based on typical clinical symptoms with positive treponemal and non-treponemal tests.
3. Early latent syphilis is defined as positive serological treponemal and non-treponemal tests with no clinical evidence of infection, with a previous negative syphilis serology,or a four-fold increase in RPR titer of a non-treponemal test within the past 12 months.Serological tests for syphilis performed within 10 days prior to study inclusion visit willbe acceptable for enrollment.
3. Signature of written informed consent.
4. Ability to comply with the requirements of the study protocol.
5. If women of childbearing potential, use of a highly effective method of contraception (abstinence,hormonal contraception, intra-uterine device \[IUD\], or anatomical sterility in self or partner)committed during 1 week after last IMP administration.
6. If men, use of condom during heterosexual intercourse and use of a highly effective method ofcontraception (abstinence, hormonal contraception, intra-uterine device \[IUD\], or anatomical sterilityin self or partner) in female partner committed during 1 week after last IMP administration.

* For inclusion purposes, positive point of care tests (POCT) will be accepted in selected patients without previous syphilis history and negative serological tests for syphilis during the last 12 months (Syphilis rapid diagnostic test \[RDT\] or Chembio DPP syphilis screen \& confirm assay \[DPP\]), or with a previous history of syphilis and negative non-treponemal tests during the last 12 months (DPP). Further confirmation by the methods described in a), b) or c) will benecessary.

Exclusion Criteria

1. Known allergy to any of the IMPs and/or excipients, particularly known hypersensitivity to penicillin, cephalosporins or other beta-lactam agents and/or allergy to soya or peanut.
2. Lactose or galactose intolerance or glucose-galactose malabsorbtion.
3. Diagnosis criteria of symptomatic neurosyphilis.
4. Pregnant or breastfeeding women.
5. Current treatment with any drugs likely to interact with the study medication (see Appendix 6).
6. Have taken any antibiotics with potential activity against syphilis (e.g. beta lactams, cephalosporines, macrolides, tetracyclines) within 1 week prior to randomization.
7. Uncontrolled hypertension, pheochromocytoma, thyrotoxicosis, carcinoid syndrome, bipolar disorder, incapacitating psycho-affective disturbance, acute confusional state.
8. Renal function impairment requiring hemodialysis.
9. Symptomatic concomitant STI (i.e., gonococcus, chlamydia, lymphogranuloma venereum, Mycoplasma genitalium) or other infection disease requiring antibiotic treatment potentially active against syphilis.
10. Having received treatment for the early syphilis recently diagnosed (In the previous 6 months)
Minimum Eligible Age

18 Years

Maximum Eligible Age

99 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia

OTHER

Sponsor Role lead

Responsible Party

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Oriol Mitja

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Oriol Mitjà Villar, PhD

Role: PRINCIPAL_INVESTIGATOR

Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia

Locations

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CAP Drassanes-Hospital Universitari Vall d'Hebron

Barcelona, Barcelona, Spain

Site Status

Barcelona Checkpoint

Barcelona, Barcelona, Spain

Site Status

Hospital Clínic de Barcelona

Barcelona, Barcelona, Spain

Site Status

Hospital Germans Trias Pujol

Barcelona, Barcelona, Spain

Site Status

Hospital 12 de Octubre

Madrid, Madrid, Spain

Site Status

Mortimer Market Centre

London, , United Kingdom

Site Status

Countries

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Spain United Kingdom

References

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Ubals M, Nadal-Baron P, Arando M, Rivero A, Mendoza A, Descalzo Jorro V, Ouchi D, Perez-Mana C, Alvarez M, Alemany A, Hoyos-Mallecot Y, Nunley E, Lieberman NAP, Greninger AL, Galvan-Casas C, Suner C, G-Beiras C, Paredes R, Rodriguez-Gascon A, Canut A, Garcia-Patos V, Farre M, Marks M, Giacani L, Vall-Mayans M, Mitja O. Oral linezolid compared with benzathine penicillin G for treatment of early syphilis in adults (Trep-AB Study) in Spain: a prospective, open-label, non-inferiority, randomised controlled trial. Lancet Infect Dis. 2024 Apr;24(4):404-416. doi: 10.1016/S1473-3099(23)00683-7. Epub 2024 Jan 8.

Reference Type DERIVED
PMID: 38211601 (View on PubMed)

Other Identifiers

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2020-005604-19

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

Trep-AB

Identifier Type: -

Identifier Source: org_study_id

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