Pre-Exposure Prophylaxis, or PrEP, is a medication that prevents HIV infection. It is intended to be used together with safer sex practices (e.g., condoms). This stacked barplot shows the number of participants in 11 different PrEP studies. The earliest study in the plot is the West Africa trial, which was initiated in 2004. Each bar corresponds to its labeled trial. The different colored sections in each bar represent the “arms” or “cohorts” of the study. Most studies have a placebo cohort and a treatment cohort. The IPERGAY study only has the treatment arm. The VOICE study has three different treatment arms, while the Partners PrEP study has two different treatment arms.
The light blue color represents the Truvada (emtricitabine/tenfovir disoproxil fumarate combination) cohorts. The dark blue color represents the cohort only given TDF (tenofovir disoproxil fumarate), and the off-white color represents the placebo cohort. The light green and pink colors represent the 1% Tenofovir vaginal gel cohort and placebo vaginal gel cohorts, respectively. The blue pill icon over a graph indicates the study employed a daily oral pill to be used as PrEP. The green gel icon indicates the study employed a topical vaginal gel to be used as PreP. We can see that all of the individuals enrolled in the studies give a combined total of over 22,000 participants. Even though PrEP is a relatively new preventative, the plot shows that a large number of participants have already enrolled in PrEP trials and the prophylaxis is becoming well studied.
About the Author
Dwayne Evans is a graduate student at SFSU. He works on HIV drug resistance in relation to Pre-Exposure Prophylaxis (PrEP). He made a figure to show how many people participated in PrEP trials since 2004.
(Please click on the reference for a link to the study)
Partners PrEP Study
Donnell D, Baeten JM, Celum C, et al. HIV Protective Efficacy and Correlates of Tenofovir Blood Concentrations in a Clinical Trial of PrEP for HIV Prevention. J Acquir Immune Defic Syndr 2014; 66: 340-348
Ndase P, Celum C, Baeten JM, et al. Successful discontinuation of the placebo arm and provision of an effective HIV prevention product after a positive interim efficacy result: the partners PrEP study experience. J Acquir Immune Defic Syndr 2014; 66:206-12
Bangkok Tenofovir Study
Choopanya K, Martin M, Vanichseni S, et al. Antiretroviral prophylaxis for HIV infection in injecting drug users in Bangkok, Thailand (the Bangkok Tenofovir Study): a randomized, double-blind, placebo-controlled phase 3 trial. The Lancet 2013; 381:2083-90
Chirwa LI, Johnson JA, Brooks JT, et al. CD4(+) cell count, viral load, and drug resistance patterns among heterosexual breakthrough HIV infections in a study of oral preexposure prophylaxis. AIDS 2014;28:223-6
West Africa Study
Peterson L, Taylor D, Cates W, et al. Tenofovir Disoproxil Fumarate for Prevention of HIV Infection in Women: A Phase 2, Double-Blind, Randomized, Placebo-Controlled Trial. PLoS Clin Trials 2007; 2:e27
CAPRISA 004 Trial
McCormack S, Dunn DT, Gill ON, et al. Pre-exposure prophylaxis to prevent the acquisition of HIV-1 infection (PROUD): effectiveness results from the pilot phase of a pragmatic open-label randomized trial. The Lancet 2015; 387:53-60
US MSM Trial
Liu A, Vittinghoff E, Buchbinder S, et al. Sexual risk behavior among HIV-uninfected men who have sex with men (MSM) participating in a tenofovir pre-exposure prophylaxis (PrEP) randomized trial in the United States. J Acquir Immune Defic Syndr 2013; 64:87-94