FIH Lead-in Study of YASO GEL Followed by a Phase 1 Randomized, Double-blind Study to Assess Safety and Pharmacokinetics of YASO GEL

This study initiates with a first-in-human lead-in study using a subtherapeutic 0.7% dose of YASO GEL. The study aims to provide a preliminary assessment of PPCM pharmacokinetics in plasma and vaginal fluid, and to validate a bioanalytical assay to be used to measure efficacy in both the Phase 1 and sub studies. Data from this study will help ensure that pharmacokinetic sampling is adequate for subsequent clinical trials and will provide initial safety information to support a Phase 1 study. The subsequent randomized double-blind Phase 1 study will use a therapeutic 2.0% dose of YASO GEL administered once in Stage 1 of the Phase 1 study and once daily for 7 days in Stage 2 of the Phase 1 study. The Phase 1 study is designed to provide comprehensive baseline safety and pharmacokinetic data in a dose response manner. As such, it is important to assess the genitalia (vulva, perineum and vagina for female participants and penis, scrotum, and perineum for male participants) after each dose for safety, initially with single dose and then with repeated dosing. Because it is anticipated that a coitally-dependent product will be applied prior to each act of coitus, and individuals may have coitus more than once a day, future studies will evaluate more frequent dosing and further characterize the YASO GEL safety profile. Secondarily, acceptability and adherence data will be collected to inform future product design and patient education. Exploratory endpoints include assessment of vaginal fluid samples for vaginal microbiome, soluble immune mediators, ex-vivo contraceptive activity and anti-microbial activity against both HIV and Ng. A sub-study is included to evaluate the impact of coitus on safety and pharmacokinetics of YASO GEL use. This study will also collect acceptability and adherence data to inform future product design and patient education. Vaginal fluid samples will be assessed for contraceptive activity and ex vivo anti-microbial activity against both HIV and Ng, in an exploratory fashion to inform future study design. The study will include healthy adult participants. Female participants will apply the gel internally in all studies. Male participants will apply the gel externally in the Lead-in and Phase 1 studies and be exposed to the gel in the coital sub-study. The results from this study will guide the design of future studies and help establish the safety and efficacy profile of YASO GEL in humans.