Trial to Assess the Impact of PrEP to Tenofovir Gel on the Efficacy of Tenofovir-containing ART on Viral Suppression

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.

Timeline

Start

2011-06

Primary completion

2014-11

Completion

2014-11

Publications

• Background De Clercq E. Acyclic nucleoside phosphonates: past, present and future. Bridging chemistry to HIV, HBV, HCV, HPV, adeno-, herpes-, and poxvirus infections: the phosphonate bridge. Biochem Pharmacol. 2007 Apr 1;73(7):911-22. doi: 10.1016/j.bcp.2006.09.014. Epub 2006 Sep 19.
• Background Schooley RT, Ruane P, Myers RA, Beall G, Lampiris H, Berger D, Chen SS, Miller MD, Isaacson E, Cheng AK; Study 902 Team. Tenofovir DF in antiretroviral-experienced patients: results from a 48-week, randomized, double-blind study. AIDS. 2002 Jun 14;16(9):1257-63. doi: 10.1097/00002030-200206140-00008.
• Background Squires K, Pozniak AL, Pierone G Jr, Steinhart CR, Berger D, Bellos NC, Becker SL, Wulfsohn M, Miller MD, Toole JJ, Coakley DF, Cheng A; Study 907 Team. Tenofovir disoproxil fumarate in nucleoside-resistant HIV-1 infection: a randomized trial. Ann Intern Med. 2003 Sep 2;139(5 Pt 1):313-20. doi: 10.7326/0003-4819-139-5_part_1-200309020-00006.
• Background Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. December 1, 2009. Available from: www.aidsinfo.nih.gov/contentfiles/AdultandAdolescentGL.pdf. Accessed 9 November 2010.
• Background Gallant JE, Staszewski S, Pozniak AL, DeJesus E, Suleiman JM, Miller MD, Coakley DF, Lu B, Toole JJ, Cheng AK; 903 Study Group. Efficacy and safety of tenofovir DF vs stavudine in combination therapy in antiretroviral-naive patients: a 3-year randomized trial. JAMA. 2004 Jul 14;292(2):191-201. doi: 10.1001/jama.292.2.191.
• Background Rohan LC, Moncla BJ, Kunjara Na Ayudhya RP, Cost M, Huang Y, Gai F, Billitto N, Lynam JD, Pryke K, Graebing P, Hopkins N, Rooney JF, Friend D, Dezzutti CS. In vitro and ex vivo testing of tenofovir shows it is effective as an HIV-1 microbicide. PLoS One. 2010 Feb 19;5(2):e9310. doi: 10.1371/journal.pone.0009310.
• Background Abdool Karim Q, Abdool Karim SS, Frohlich JA, Grobler AC, Baxter C, Mansoor LE, Kharsany AB, Sibeko S, Mlisana KP, Omar Z, Gengiah TN, Maarschalk S, Arulappan N, Mlotshwa M, Morris L, Taylor D; CAPRISA 004 Trial Group. Effectiveness and safety of tenofovir gel, an antiretroviral microbicide, for the prevention of HIV infection in women. Science. 2010 Sep 3;329(5996):1168-74. doi: 10.1126/science.1193748. Epub 2010 Jul 19.
• Naicker N, Naidoo A, Werner L, Garrett N, Majola N, Asari V, Baxter C, Grobler A, Karim QA, Karim SSA. Efficacy and safety of tenofovir-containing antiretroviral therapy in women who acquired HIV while enrolled in tenofovir gel prophylaxis trials. Antivir Ther. 2017;22(4):287-293. doi: 10.3851/IMP3106. Epub 2016 Nov 4.

Drugs

Indications

No indication recorded.