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

The proposed project is designed to evaluate the effectiveness of cefixime (400mg, twice a day, for 10 days) compared to benzathine penicillin G (2.4 million units, intramuscularly) in patients with and without HIV infection. Syphilis rates have been increasing both in the US and internationally. Incidence is higher among men-who-have-sex-with-men and more importantly in individuals with HIV infection. Currently, penicillin is used to treat syphilis in patients with and without HIV infection. Doxycycline, tetracycline and ceftriaxone are alternative treatments for non-pregnant patients who are allergic to penicillin. Existing treatment alternatives are based on clinical experience, a limited number of small clinical trials, and case series, but each poses clinical challenges. New, safe and efficacious antibiotic treatment options are needed. In this proposal, we will build upon our successful pilot study to conduct a randomized, multisite, open-label, noninferiority clinical trial to evaluate the effectiveness of cefixime (400mg, twice a day, for 10 days) compared to benzathine penicillin G (2.4 million units, intramuscularly) in patients with and without HIV infection. We will enroll 360 participants with early syphilis infection from 9 clinical sites in the U.S. We will follow the participants to monitor clinical progress and serological response (RPR titer) every 3 months for 9 months. Our hypothesis is that cefixime will be non-inferior to penicillin in treating syphilis, shown as a 4-fold decrease in RPR titer from enrollment to 6-months after treatment administration. These are the two specific aims of our proposal. AIM 1: Evaluate the effectiveness of cefixime in the treatment of early syphilis when compared to benzathine penicillin G. AIM 2: Determine the predictors of treatment failure among participants. RELEVANCE (See instructions):