Tenofovir/Levonorgestrel

This multi-center Phase I study is designed to characterize the safety, PK, and PD of TFV/LNG IVR to assess systemic and genital tract bioavailability in healthy women. The IVRs to be used in the study are TFV/LNG IVR (8-10mg per day/20μg per day) or placebo IVR. Samples will be obtained before, during and after 90 days of continuous or interrupted IVR use.

The purpose of the study is to evaluate the safety of the TFV/LNG intravaginal ring (IVR), TFV-only IVR, and placebo IVR, evaluate pharmacokinetics (PK) of TFV and LNG, evaluate pharmacodynamic (PD) surrogates of contraceptive efficacy of LNG, and to evaluate acceptability of the IVRs.