Phase 4 Comparative Trial of Benzathine Penicillin G for Treatment of Early Syphilis in Subjects With or Without HIV Infection

This is a phase 4, randomized, open-label, multicenter trial to evaluate the efficacy of a single injected dose of Benzathine Penicillin G (BPG) 2.4 MU (Arm 1) compared to three successive weekly injected doses of BPG 2.4 MU (Arm 2) for treatment of early syphilis in human immunodeficiency virus (HIV)-infected and HIV-uninfected subjects. The study will enroll 560 adults (to achieve 420 evaluable subjects) aged 18 years or older with untreated early syphilis (primary, secondary, or early latent). It will be conducted at 9 sites in the US and last for 48 months with patient participation duration of 12 months. The primary objective is to compare the serological response to therapy in subjects with early (primary, secondary, or early latent) syphilis treated with Benzathine Penicillin G (BPG) 2.4 million units (MU) once or weekly for three successive weeks. The secondary objectives are: 1) to determine if the difference in response to therapy between treatment arms by Month 6 differs among subjects with or without HIV infection; 2) to determine the impact of multiple BPG injected doses on subject compliance with study product and adherence to the corresponding scheduled visits; 3) to determine the incidence and manifestations of the Jarisch-Herxheimer reaction among subjects treated for early syphilis with BPG; 4) to collect prospective data up to Month 12 on the serological response to therapy in subjects treated for early syphilis with either BPG regimen; 5) to compare epidemiological characteristics of early syphilis among subjects with or without HIV infection.