MTN-021

It can be predicted that once vaginal microbicide products such as tenofovir gel are approved for marketing, they would likely be used by females of all ages. Safety data for 1% tenofovir gel in adolescents has been requested by the FDA prior to product approval. MTN-021 is a Phase 1, two-arm, placebo-controlled, double-blinded, multi-site, randomized trial of repeated exposure (once daily for approximately 12 weeks) to 1% tenofovir gel applied vaginally in sexually experienced, HIV-uninfected adolescent females. This study is a collaborative effort between the MTN and the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) funded by NICHD. Approximately 90 adolescent females will be randomized in a 2:1 ratio to one of the following study groups: 1% tenofovir gel or placebo gel. A total of 20 evaluable participants will have blood drawn for this PK study and will be asked to insert a dose of gel at their 4-Week Study Visit followed by a single time-point PK measurement of tenofovir blood levels approximately 2 hours after gel insertion.