A Phase 3 interventional study of Cefixime 400mg and benzathine penicillin in Syphilis and Human Immunodeficiency Virus, sponsored by University of Southern California. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by University of Southern California · Phase 3, Interventional, and Treatment
This study aims to evaluate the efficacy of cefixime compared to benzathine penicillin G in the treatment of syphilis.
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.
126 studies on the registry are indexed under Syphilis; 34 are open to participants now.
This study's planned enrollment of 400 is above the median of 354 across 85 interventional studies indexed under Syphilis.
Browse Syphilis studies →University of Southern California is the lead sponsor of 791 studies on the registry; 136 are open to participants now.
Of its 70 completed or terminated interventional studies of FDA-regulated products, 32 (46%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CD4 count
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Oral cefixime 400mg, taken twice a day for 10 days
Drug: Cefixime 400mg
Single intramuscular injection of 2.4 million units of benzathine penicillin G
Drug: benzathine penicillin
Oral cefixime 400 mg, one capsule, twice a day for 10 days
Also known as: supprax
Standard of care benzathine penicillin G, one intramuscular injection, 2.4MU
Also known as: bicillin
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
Time frame: 6 months
Plan to share: No — No IPD will be shared with other researchers
No publications or documents are linked to this record.
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Studies of the drug tested here: Cefixime
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