Cefixime Clinical Trial

Clinical Trial Comparing the Effectiveness of Cefixime Versus Penicillin G for Treatment of Early Syphilis

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

Study Overview

• Status: Recruiting
• Conditions: Human Immunodeficiency Virus; Syphilis
• Intervention / Treatment: Drug: Cefixime 400mg; Drug: benzathine penicillin

Detailed Description

This will be a randomized, multisite, open-label, non-inferiority clinical trial to evaluate the effectiveness of cefixime (400mg orally, twice a day, for 10 days) compared to benzathine penicillin G (2.4 million units, intramuscularly) in patients with and without HIV infection. In total, 400 participants with early syphilis will be enrolled from 9 clinical sites in the U.S. and Peru. Participants will participate in follow-ups to monitor clinical outcomes and serological response (RPR titer) every 3 months for 9 months. Study findings may identify an efficacious alternative syphilis treatment to penicillin, effective for people living with HIV infection, to help address the crisis of penicillin shortages and offer options for those with penicillin allergy.

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Jeffrey D Klausner; Phone Number: (415) 876-8901; Email: jdklausner@med.usc.edu

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90032
      • Recruiting
      • University of Southern California
      • Contact: Jeffrey D Klausner, MD; Phone Number: (415) 876-8901; Email: jdklausner@med.usc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Benzathine Penicillin G; Single intramuscular injection of 2.4 million units of benzathine penicillin G	Drug: benzathine penicillin; Standard of care benzathine penicillin G, one intramuscular injection, 2.4MU; Other Names: bicillin
Experimental: Cefixime; Oral cefixime 400mg, taken twice a day for 10 days	Drug: Cefixime 400mg; Oral cefixime 400 mg, one capsule, twice a day for 10 days; Other Names: supprax

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Response to treatment	Percentage of cefixime participants with a 4-fold decrease or greater in the serum RPR titer 3 or 6 months after treatment completion	6 months

Collaborators and Investigators

• Sponsor: University of Southern California
• Collaborators: Universidad Peruana Cayetano Heredia; AIDS Healthcare Foundation
• Investigators: Principal Investigator: Jeffrey D Klausner, MD MPH, University of Southern California

Study record dates

Study Major Dates

• Study Start (Actual): June 20, 2021
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: June 29, 2021
• First Submitted That Met QC Criteria: June 29, 2021
• First Posted (Actual): July 12, 2021

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Penicillin; Treponema pallidum; Early Syphilis; Cefixime
• Additional Relevant MeSH Terms: Blood-Borne Infections; Urogenital Diseases; Genital Diseases; Immune System Diseases; Infections; RNA Virus Infections; Virus Diseases; Communicable Diseases; Sexually Transmitted Diseases, Viral; Sexually Transmitted Diseases; Lentivirus Infections; Retroviridae Infections; Immunologic Deficiency Syndromes; Slow Virus Diseases; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Negative Bacterial Infections; Spirochaetales Infections; HIV Infections; Sexually Transmitted Diseases, Bacterial; Acquired Immunodeficiency Syndrome; Syphilis; Treponemal Infections; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Amides; Penicillin G; beta-Lactams; Lactams; Cephalosporins; Thiazines; Penicillins; Cefotaxime; Cephacetrile; Cefixime; Penicillin G Benzathine
• Other Study ID Numbers: HS-21-00288

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No IPD will be shared with other researchers

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No