Conditions: HIV Infections
Keywords: Microbicide HIV Seronegativity
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 168
Healthy volunteers: yes

Brief summary:
A new approach to HIV prevention currently being studied includes the use of microbicides, substances that kill microbes. Tenofovir disoproxil fumarate (TDF) is an oral, FDA-approved, anti-HIV drug, and tenofovir gel is an experimental microbicide. The purpose of this study is to determine the adherence and acceptability to and blood levels of three daily regimens of tenofovir in both oral and gel form.

Detailed description:
It is necessary to monitor both the adherence and blood levels of microbicides in order to gauge its efficacy in a study population. Utilizing an experimental microbicide (tenofovir gel) and an anti-HIV drug (TDF), this study will measure the adherence and acceptability to and blood levels of the two interventions in three separate regimens given to HIV-uninfected women.

The expected duration of participation for each participant is 21 weeks. Study participants will be randomly assigned into one of six study groups, each with a different regimen sequence. Each sequence will consist of three study periods and three wash-out periods. Each study period lasts 6 weeks, followed by a 1 week wash-out period. The regimen assigned for a given study period will include either oral TDF, tenofovir vaginal gel, or both. All participants will be prescribed all three regimens in the order designated by their randomized assignment.

Study visits will occur at Weeks 1, 3, 6, 7, 10, 13, 14, 17, 20, and 21. Medical history, a physical exam, behavioral assessment, and urine, blood, pelvic sample collection, and counseling will occur at all visits. At some study sites rectal swabs may be performed. Counseling will include information regarding contraception, protocol adherence, HIV, HIV/Sexually Transmitted Infection risk reduction, and male condom use. Pharmacokinetic (PK) studies, to be determined by the study site, will occur during all three study periods. These studies may involve additional procedures.

Arms:
arm 1: Oral tenofovir disoproxil fumarate (TDF) for Weeks 1 through 6, vaginal tenofovir gel application for Weeks 8 through 13, and oral TDF and vaginal tenofovir gel application for Weeks 15 through 20 arm 2: Vaginal tenofovir gel application for Weeks 1 through 6, oral TDF for Weeks 8 through 13, and oral TDF and vaginal tenofovir gel application for Weeks 15 through 20 arm 3: Oral TDF and vaginal tenofovir gel application for Weeks 1 through 6, oral TDF for Weeks 8 through 13, and vaginal tenofovir gel application for Weeks 15 through 20 arm 4: Oral TDF and vaginal tenofovir gel application for Weeks 1 through 6, vaginal tenofovir gel application for Weeks 8 through 13, and oral TDF for Weeks 15 through 20 arm 5: Oral TDF for Weeks 1 through 6, oral TDF and vaginal tenofovir gel application for Weeks 8 through 13, and vaginal tenofovir gel application for Weeks 15 through 20 arm 6: Vaginal tenofovir gel application for Weeks 1 through 6, oral TDF and vaginal tenofovir gel application for Weeks 8 through 13, and oral TDF for Weeks 15 through 20

Interventions: intervention 1: Tenofovir disoproxil fumarate intervention 2: Tenofovir gel
Intervention descriptions: intervention 1: 300 mg tablet daily intervention 2: 1 gm/100 ml of 1% gel vaginally daily

Protocol document: