Recruiting
Phase 3

Cefixime

Sponsor:

University of Southern California

Code:

NCT04958122

Conditions

Syphilis

Human Immunodeficiency Virus

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Cefixime 400mg

benzathine penicillin

Study Details

Brief summary:

This study aims to evaluate the efficacy of cefixime compared to benzathine penicillin G in the treatment of syphilis.

Conditions

Syphilis

Human Immunodeficiency Virus

Study ID

NCT04958122

Start date

Jun 20, 2021

Status verified date

Apr, 2026

Completion date

Jun 30, 2027

Anticipated

Primary completion date

Jan 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Diagnosed cases of primary, secondary, or early latent syphilis with RPR titer ≥1:8 within 3 weeks prior to enrollment
  • 18 years of age or older
  • Able to provide informed consent
  • 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 according to most recent labs before study enrollment

Exclusion Criteria:

  • Pregnancy or a positive pregnancy test on the day of enrollment
  • Patients showing signs and symptoms of neurosyphilis
  • 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, doxycycline, 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
  • Self-reported allergy to cephalosporins or penicillin
  • Unwilling or unable to attend follow-up visits

Study Design

Enrollment

400 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Cefixime

Oral cefixime 400mg, taken twice a day for 10 days

active comparator: Benzathine Penicillin G

Single intramuscular injection of 2.4 million units of benzathine penicillin G

Interventions

Cefixime 400mg

Oral cefixime 400 mg, one capsule, twice a day for 10 days

benzathine penicillin

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

Primary outcome measure

  • Response to treatment [ Time Frame: 6 months ]

Central Contacts and Locations

Central contacts

Jeffrey D Klausner

(415) 876-8901jdklausner@med.usc.edu

Locations

University of Southern California

Recruiting

Los Angeles, California, United States, 90032

Contacts

Jeffrey D Klausner, MD

(415) 876-8901jdklausner@med.usc.edu

More Information

Sponsor

University of Southern California

Last update posted

May 4, 2026

Last verified

Apr, 2026

Keywords

  • Cefixime
  • Treponema pallidum
  • Penicillin
  • Early Syphilis

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Southern California on 2026-05-04.