Women account for a large proportion of new HIV infections globally. The Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial demonstrated that Tenofovir (TFV) vaginal gel reduced HIV acquisition by an estimated 39% overall. There are difficulties with adherence to daily or pericoitally dosed intravaginal gels. The development of delivery systems that overcome difficulties associated with adherence, such as intravaginal rings, may result in greater reductions in the rates of HIV-1 infection.

This phase 1 study is a two-site, two-arm, randomized single-blind placebo-controlled trial which aims to assess safety of Tenofovir Disoproxil Fumarate (TDF) Intravaginal Ring (IVR) when used by healthy, HIV uninfected, sexually active women, as compared with the placebo IVR. Secondary objectives are to examine systemic and genital tract pharmacokinetics (PK) of TDF and its metabolites and evaluate the acceptability of the study IVR.

The study will be conducted in Albert Einstein College of Medicine (Einstein), Bronx, USA and Partners in Health & Research Development Site, Thika, Kenya. The study will recruit 80 women (40 US and 40 African) who are Healthy, sexually active, HIV uninfected between the ages of 18 and 45 on contraception.

Accrual of participants will require approximately 12 months. Each participant will engage in the screening process for up to 28 days prior to enrolment. Enrolled participants will use the TDF IVR continuously for 84 days, and will have clinic visits every 14 days. Twenty US women will participate in a 30-day run-in phase to assess safety prior to initiation of enrollment in Kenya.