Preclinical Safety and Efficacy Assessments of Dendrimer-Based (SPL7013) Microbicide Gel Formulations in a Nonhuman Primate Model

Three gel formulations (1%, 3%, and 5% [wt/wt]) of SPL7013, a dendrimer known to have antiviral (anti-human immunodeficiency virus and anti-herpes simplex virus) activities, completed a range of preclinical tests in the pigtailed macaque models for vaginally and rectally applied topical microbicide safety assessments. The vaginal safety profile of the 3% SPL7013 gel formulation was equal to that of the 1% formulation but was superior to that of the 5% formulation. The 3% SPL7013 gel was further evaluated for rectal safety and for antichlamydial efficacy with cervical challenge with Chlamydia trachomatis. This first-generation dendrimer-based product was shown to be safe to the vaginal and rectal microenvironments with repeated daily use. However, a single intravaginal application of the 3% (wt/wt) SPL7013 gel did not provide protection from the acquisition of cervical chlamydial infection.