Trial to Assess the Impact of PrEP to Tenofovir Gel on the Efficacy of Tenofovir-containing ART on Viral Suppression
Status:
Completed
Trial end date:
2014-11-01
Target enrollment:
Participant gender:
Summary
The HIV/AIDS pandemic remains among the investigators greatest public health challenges. In
the absence of an effective vaccine, focus has shifted to other prevention strategies such as
pre-exposure prophylaxis. Tenofovir, with potent activity against retroviruses [1], was
developed for oral use as Viread®, which is widely used for HIV treatment. The efficacy of
Viread® has been demonstrated in treatment-experienced and naïve patients [2,3]. In
antiretroviral-naive patients, the combination of tenofovir with lamivudine and efavirenz has
been classified as a preferred regimen in the Department of Health and Human Services
treatment guidelines[4], and has been adopted by the South African Department of health as
the first line regimen in treatment-naïve HIV infected patients since April 2010. The
durability of antiviral response, favourable resistance profile, once daily dosing, and
excellent long term safety profile of tenofovir [5], makes this drug an attractive option in
both treatment and prevention regimens and its long half-life [6], made it an ideal choice as
the first antiretroviral drug to be formulated as a microbicide gel.
The CAPRISA 004 study conducted in South Africa which tested the effectiveness and safety of
1% tenofovir gel showed that the use of tenofovir in a gel formulation reduced HIV
acquisition by 39% overall, and by 54% in women with high gel adherence [7]. There have been
concerns raised regarding the use of tenofovir in both PrEP and treatment regimens due to the
potential for selection of viral mutations and development of resistance in patients who have
become HIV-infected while on PrEP.
There have been no studies conducted to determine whether using tenofovir in pre-exposure
prophylaxis affects treatment outcomes in patients who later use tenofovir, which is part of
the first line ART of South Africa.
This study aims to determine whether prophylactic exposure to tenofovir gel alters the
therapeutic response to a tenofovir containing antiretroviral regimen.
Phase:
N/A
Details
Lead Sponsor:
Centre for the AIDS Programme of Research in South Africa