Use of a Vaginal Ring Containing Dapivirine for HIV-1 Prevention in Women

Abstract

BACKGROUND Antiretroviral medications that are used as prophylaxis can prevent acquisition of human immunodeficiency virus type 1 (HIV-1) infection. However, in clinical trials among African women, the incidence of HIV-1 infection was not reduced, probably because of low adherence. Longer-acting methods of drug delivery, such as vaginal rings, may simplify use of antiretroviral medications and provide HIV-1 protection. METHODS We conducted a phase 3, randomized, double-blind, placebo-controlled trial of a monthly vaginal ring containing dapivirine, a non-nucleoside HIV-1 reverse-transcriptase inhibitor, involving women between the ages of 18 and 45 years in Malawi, South Africa, Uganda, and Zimbabwe. RESULTS Among the 2629 women who were enrolled, 168 HIV-1 infections occurred: 71 in the dapivirine group and 97 in the placebo group (incidence, 3.3 and 4.5 per 100 person-years, respectively). The incidence of HIV-1 infection in the dapivirine group was lower by 27% (95% confidence interval [CI], 1 to 46; P = 0.05) than that in the placebo group. In an analysis that excluded data from two sites that had reduced rates of retention and adherence, the incidence of HIV-1 infection in the dapivirine group was lower by 37% (95% CI, 12 to 56; P = 0.007) than that in the placebo group. In a post hoc analysis, higher rates of HIV-1 protection were observed among women over the age of 21 years (56%; 95% CI, 31 to 71; P<0.001) but not among those 21 years of age or younger (-27%; 95% CI, −133 to 31; P = 0.45), a difference that was correlated with reduced adherence. The rates of adverse medical events and antiretroviral resistance among women who acquired HIV-1 infection were similar in the two groups. CONCLUSIONS A monthly vaginal ring containing dapivirine reduced the risk of HIV-1 infection among African women, with increased efficacy in subgroups with evidence of increased adherence. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01617096.)

The influence of social constructs of hegemonic masculinity and sexual behaviour on acceptability of vaginal microbicides in Zambia

“…To curb women's vulnerability to HIV, vaginal microbicides were initially seen as an essential element in empowering women to be able to protect themselves from HIV (Baeten et al, 2016;Heise & Elias, 1995;Karim et al, 2013). However, this study suggests that women's decisions to use microbicides gel are located within the parameters set by their social relationships with their partners and other members of society as they construct and practice gender in the context of social change.…”

“…Microbicides are formulated in many ways, including gel, film and ring form (Baeten et al, 2016;Shattock & Rosenberg, 2012). This research paper draws on participants who used the gel in the Microbicides Development Program (MDP) clinical trial.…”

“…So far, only two products have shown significant results in preventing HIV (Abdool Karim et al, 2010;Baeten et al, 2016;Nel et al, 2016). The first is the CAPRISA 004 Phase IIb study, which showed that Tenofovir reduced HIV by 39% (Abdool Karim et al, 2010).…”

“…This result could not be replicated in a phase III trial (Rees et al, 2015). Recently, two studies of Dapivirine, administered using a monthly vaginal ring, showed effectiveness against HIV-1 among women, in phase III trials conducted in Africa (Baeten et al, 2016;Nel et al, 2016).…”

Zika Virus Disease

“…Application of vaginal rings shedding an antiviral substance such as Dapivirine could be useful but is not yet approved for this purpose (50).…”