Examining Hair to Determine Tenofovir Exposure

HIV Clinical Trial

Official title: A Phase 1 Pharmacokinetic Study of Varying Dosing Patterns on Tenofovir Concentrations in Hair

Status Completed

Clinical Trial Summary

This study will determine whether a hair test can reveal how much of the anti-HIV medication tenofovir a person without HIV has been exposed to.

Clinical Trial Description

Pre-exposure prophylaxis (PrEP) is a new strategy for the prevention of HIV infection. It involves providing antiretroviral medications—those that treat HIV infections—to people before they are exposed to HIV. In clinical trials of PrEP, several of which are currently under way, accurate measurements are needed of how much exposure participants have to the PrEP medications. Current methods, such as self-reports of medication adherence or pill counting, can lead to inaccurate readings of PrEP exposure because participants may forget to take pills and individual differences may affect levels of exposure. Measuring PrEP exposure levels in hair yields an objective marker of exposure that is not subject to self-report errors and that takes into account individual differences. This study will test the use of a hair sample for assessing the level of exposure to tenofovir disoproxil fumarate (TDF), an antiretroviral medication, in people not infected with HIV.

Participation in this study will last 9 months. Participants will undergo baseline testing and then will be randomly assigned to begin one of three conditions, based on dosing schedule: receiving TDF 2, 4, or 7 days per week. All participants will complete each of these dosing schedules, but the order in which they are completed will be randomly assigned. Each dosing schedule will last 6 weeks, with a break of several weeks between them. During each dosing schedule, study staff will confirm that participants are taking each scheduled dose by watching them take the pills on weekdays and calling them on weekends. Follow-up visits will occur at Days 1, 21, and 42 of each dosing schedule. During the baseline and follow-up visits, the following will be completed: an HIV rapid test; counseling about HIV prevention; a brief physical exam; a talk with a staff member about health, symptoms, and other medications; a blood draw, which will be used for several tests; collection of a urine sample and pregnancy test; and optional donation of a sample of pubic hair. On the last day of each dosing schedule, a small sample of hair will be cut from each participant's scalp. An additional follow-up visit will occur after participants complete 4 weeks of the 7-day dosing schedule. This visit will last 24 hours and will involve collection of additional blood samples. ;

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacokinetics Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Prevention

Related Conditions & MeSH terms

• HIV

• NCT number: NCT00903084
• Study type: Interventional
• Source: Public Health Foundation Enterprises, Inc.
• Status: Completed
• Phase: Phase 1
• Start date: June 2009
• Completion date: June 2010