Linezolid for Syphilis Pilot Study

NCT05548426 | Active Not Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: APP-22-04165
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 5

Brief Summary

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

Conditions

Syphilis

Keywords

Linezolid; Treponema pallidum; Penicillin; Early Syphilis

Outcome Measures

Primary Outcomes (1)

• Response to Treatment

  Percentage of linezolid participants with a 4-fold decrease or greater in the serum RPR titer by 180 days after treatment

  6 months

Study Arms (2)

Linezolid 10 Day

EXPERIMENTAL

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

Drug: Group B, Linezolid 10d

Benzathine Penicillin G

ACTIVE COMPARATOR

Single intramuscular injection of 2.4 million units of benzathine penicillin G

Drug: Group A, Penicillin

Interventions

Group B, Linezolid 10d DRUG

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

Also known as: zyvox

Linezolid 10 Day

Group A, Penicillin DRUG

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

Also known as: bicillin

Benzathine Penicillin G

Eligibility Criteria

• Age: 16 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnosed cases of primary, secondary or early latent syphilis with RPR titer ≥1:8 within 3 weeks prior to enrollment
• years of age or older
• Able to provide informed consent/assent.
• 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.

You may not qualify if:

• Pregnancy or a positive pregnancy test on the day of enrollment
• Patients showing signs and symptoms of neurosyphilis.
• Participants who receive certain psychotropic medications, e.g., MAO inhibitors, SNRIs, SSRIs
• Serofast RPR titer, defined as persistently positive RPR titer without more than 4-fold (2-titer level) change for 12 months or greater.
• 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)
• Individuals with HIV infection who report HIV treatment interruption for more than 4 weeks since their most recent viral load or CD4 test.
• Individuals with known myelosuppressive conditions or receiving myelosuppressive medication
• Individuals weighing 150kg (330 lbs) or more.
• Individuals with known end renal stage disease, for example individuals in hemodialysis.
• Self-reported allergy to linezolid or penicillin.
• Unwilling or unable to attend follow-up visits.

Sponsors & Collaborators

• University of Southern California: lead

Study Sites (5)

Howard Brown Health

Chicago, Illinois, 60613, United States

Location

Open Arms HealthCare Center

Jackson, Mississippi, 39216, United States

Location

University of Mississippi Medical Center

Jackson, Mississippi, 39216, United States

Location

Wake Forest Baptist Health

Greensboro, North Carolina, 27405, United States

Location

Open Door Health

Providence, Rhode Island, 02907, United States

Location

MeSH Terms

Conditions

Syphilis; Treponemal Infections

Interventions

Linezolid; Penicillins; Penicillin G Benzathine

Condition Hierarchy (Ancestors)

Spirochaetales Infections; Gram-Negative Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Infections; Sexually Transmitted Diseases, Bacterial; Sexually Transmitted Diseases; Communicable Diseases; Genital Diseases; Urogenital Diseases

Intervention Hierarchy (Ancestors)

Acetamides; Amides; Organic Chemicals; Acetates; Acids, Acyclic; Carboxylic Acids; Oxazolidinones; Oxazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; beta-Lactams; Lactams; Sulfur Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Penicillin G

Study Officials

• Jeffrey D Klausner, MD MPH

  University of Southern California

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Professor

Study Record Dates

• First Submitted: September 16, 2022
• First Posted: September 21, 2022
• Study Start: September 28, 2023
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: March 12, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (5)