A Pilot Study of Pre-Exposure Prophylaxis (PrEP) to Evaluate Safety, Acceptability, and Adherence in At-risk Populations in Uganda, Africa

Phase 1

Completed

• Conditions: HIV Infection
• Interventions: Drug: FTC/TDF; Drug: Placebo

• Registration Number: NCT00931346
• Lead Sponsor: International AIDS Vaccine Initiative

Brief Summary

This study will evaluate the safety and acceptability of intermittent and daily pre-exposure prophylaxis (PrEP) regimens with FTC/TDF (emtricitabine/tenofovir disoproxil fumarate) in HIV discordant couples, and it will directly compare adherence and intracellular drug levels in daily and intermittent PrEP recipients. It will also evaluate the relationship between drug adherence, sexual behavior and intracellular drug levels with an intermittent PrEP regimen. In addition it will evaluate the relationship between adherence to an intermittent PrEP regimen and timing of sexual activity in relation to PrEP dosing. The pilot will use objective medication event monitoring (MEMS) adherence measurement and evaluate the feasibility of newer adherence measurements such as hair sampling and plasma drug levels. This study will also evaluate the feasibility of using text messaging (SMS) to collect sexual activity data in an African setting. It will allow study teams and communities to prepare for potential subsequent larger trials of intermittent PrEP. The study is not sized to evaluate efficacy. If the intermittent PrEP regimen is safe, feasible in terms of adherence, and achieves intracellular drug levels similar to daily PrEP, the data could be used to design a larger phase 2 study with one or more intermittent PrEP regimens. The goal of such a larger trial would be to provide bridging data if daily PrEP regimens are found to be effective or to prepare for efficacy or non-inferiority trials of intermittent versus daily PrEP.

Investigation of immune responses associated with FTC/TDF will also be evaluated in the pilot study. The proportion of volunteers on FTC/TDF with HIV-specific immune responses, due to exposures that did not lead to established HIV infection, will be assessed at 2-3 time points and compared to responses in volunteers assigned to placebo. Immune responses may be correlated with risk behavior and host factors, such as human leukocyte antigen (HLA) type. As noted above, very few HIV infections are expected to occur during the study, so correlation of HIV-specific immune responses and protection from infection or attenuation of disease progression will not be possible until a larger study is conducted.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2009-06-29
• Study First Submitted QC: 2009-06-30
• Study First Posted: 2009-07-02
• Study Start: 2009-10
• Primary Completion: 2010-10
• Study Completion: 2010-10
• Status Verified: 2011-08
• Last Update Submitted: 2011-08-24
• Last Update Posted: 2011-08-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 72

Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
FTC/TDF Daily	FTC/TDF	Daily dosing
FTC/TDF Intermittent	FTC/TDF	Dosed intermittently
Placebo Daily	Placebo	Placebo dosed daily
Placebo Intermittent	Placebo	Placebo dosed intermittently, orally.

Primary Outcome Measures

Name	Time	Method
Safety and tolerability: volunteers with moderate and greater severity clinical adverse events, renal toxicities, and other moderate and severe laboratory abnormalities.	6 months
Acceptability: proportion of volunteers who report willingness to use the study regimen; the acceptability to the HIV-infected partner of their partner using the investigational product	6 months
Intracellular drug concentrations: the mean intracellular drug concentration for each group assigned to FTC/TDF	6 months
Adherence: proportion of vol. who took, by MEMS data, at least 80% of doses; vol. assigned to FTC/TDF with detectable drug plasma levels within 48 hrs of use; relationship between intracellular drug levels and adherence in vol. assigned to FTC/TDF	6 months
Behavioral: reported number of steady and casual sex partners; frequency of unprotected vaginal intercourse; substance use prior to or during sex	6 months

Secondary Outcome Measures

Name	Time	Method
The proportion of volunteers who report somewhat high or high levels of burden in using electronic medication monitoring to measure adherence, and using cell phone communication to measure sexual activity	6 months
The proportion of study days with missing SMS sexual activity data	6 months
The proportion of volunteers assigned to placebo who have detectable intracellular drug levels	6 months
The proportion of HIV-infected partners in discordant couples not on ART with detectable drug levels	6 months
The proportion of volunteers with HIV-specific immune responses as measured by analysis of cellular or humoral immune response, or changes in gene regulation as measured by microarray or proteomic techniques	6 months
The proportion of volunteers who report sharing medications	6 months

Trial Locations

Locations (1)

MRC-Entebbe; 🇺🇬 Entebbe, Uganda