Study results provide critical new data to guide HIV prevention and treatment efforts for women and girls

Press Release from AIDS 2016

FOR RELEASE
Monday, 18 July 2016
12:15PM SAST

CAPRISA Studies Shed New Light on Why Young Women in South Africa Have High HIV Rates
Additional Research Shows Promising Results for New Prevention and Treatment Options but Underscore Significant Challenges with Treatment Acceptance and Adherence

Durban, South Africa – Multiple studies discussed today in an official press briefing at the 21st International AIDS Conference (AIDS 2016) in Durban collectively provide new insights that will help shape future HIV prevention and treatment efforts for women and girls. Three studies by the Centre for the AIDS Programme of Research in South Africa (CAPRISA) provide new evidence on the factors that contribute to high rates of HIV infection in young women in South Africa. A new analysis of the landmark ASPIRE vaginal ring study reveals high levels of HIV protection among women who consistently used the intervention. A series of studies from the PROMISE trials provides encouraging data on options for preventing mother-to-child HIV transmission during extended breastfeeding, but also raises concerns about treatment adherence and acceptance among HIV-positive women who had recently given birth. And another study shows high efficacy and safety of a simplified, fixed-dose combination regimen for treatment-naïve women.

“These new insights pave the way to develop new prevention and treatment approaches that will protect the health of women, girls, and newborns,” said Chris Beyrer, AIDS 2016 International Chair and President of the International AIDS Society. “With women accounting for the majority of adults living with HIV in sub-Saharan Africa, and new infections among young women double that of young men in the region, it has never been more critical to address this vital issue.”

Commenting specifically on the CAPRISA studies discussed in today’s press briefing, Salim S. Abdool Karim, Director of CAPRISA, said: “Reducing new HIV infections in young women is one of the greatest challenges in Africa. Based on our results, implementing targeted prevention interventions to break the cycle of HIV transmission while effectively treating bacterial vaginosis could reverse the devastating impact of the HIV epidemic in young people in Africa.”

Research featured in the briefing included:

Age-disparate sex and specific vaginal bacteria increase HIV risk among young women in South Africa: Three CAPRISA-led studies sought to explain why young women in South Africa have high rates of HIV. One of the studies analysed the genetic HIV code from 1,589 HIV-positive people to better understand the persistent spread of HIV in a rural and an urban community in South Africa. It revealed a cycle of HIV transmission driven by high rates of new HIV infections in adolescent girls and young women from men, who were on average eight years older. Many of these men were also partners of similarly aged women, among whom HIV prevalence exceeds 60 percent.

Two additional studies investigated the role of vaginal bacteria in HIV risk. One examined the vaginal bacteria of 120 women, and found that those with an overgrowth of Prevotella bivia had an almost 20 times higher chance of acquiring HIV than those with low levels or absence of this vaginal bacterium. The other study analysed 3,334 genital bacterial proteins from 688 women, which showed that three out of five women who had “healthy” (lactobacillus-dominant) vaginal bacteria benefitted from tenofovir gel pre-exposure prophylaxis; the other women did not. Follow-up laboratory studies showed that the vaginal bacteria Gardenerella vaginalis, which predominates in the vagina when lactobacillus is not dominant, absorbs tenofovir thereby reducing its availability in the genital tract to prevent HIV infection.

[All CAPRISA data are currently under journal review; no abstracts are available.]

  • Session: New Evidence: Why Do Young Women in Africa Have High Rates of HIV Infection? (Session Room 1; Tuesday 19 July, 14:30 – 15:30)
    • Who is infecting who? Community-wide phylogenetic transmission networks reveal young women’s high HIV exposure from older men with low ART coverage
    • Role of vaginal microbiota in genital inflammation and enhancing HIV acquisition in women
    • Uncovering the role of the vaginal microbiome in undermining PrEP efficacy in women

Higher adherence to dapivirine vaginal ring associated with greater protection: Results of the ASPIRE study presented earlier this year at CROI indicated that a dapivirine vaginal ring decreased HIV risk by only 27 percent overall, and that efficacy differed significantly by age. The new analysis, including only those women who used the vaginal ring as directed (n=2,359), was discussed today by Jared Baeten, co-author of the study and Vice Chair of Global Health at the University of Washington School of Public Health. It showed that the ring reduced HIV risk by 65 percent, and point estimates suggested protection regardless of age (72% risk reduction for women >21 [95% CI 21-90] and 50 percent risk reduction for women ≤21 [95% CI 78-86]). These promising new findings add to the growing body of research underscoring the importance of adherence to biomedical prevention tools and give new hope to the continued development of the vaginal ring as a potential prevention option. [Summary based on submitted abstract; updated data may be presented on site.]

  • Abstract: Residual Dapivirine Ring Levels Indicate Higher Adherence to Vaginal Ring is Associated with HIV-1 Protection
  • Session: PrEP: New Drugs, New Questions (Session Room 11; Tuesday 19 July, 11:00 – 12:30 SAST)

Maternal triple antiretrovirals and infant prohylaxis both safe/effective methods for reducing mother-to-child transmission during breastfeeding: The first trial to directly compare the efficacy and safety of maternal triple antiretrovirals (mART) and infant nevirapine (iNVP) prophylaxis as strategies to reduce infant morbidity and mortality during extended breastfeeding found that both strategies were associated with very low transmission rates and high infant survival rates. HIV-infected women with CD4+ counts >350 cells/mm3 (or > country-specific threshold for therapy if higher) and their HIV-uninfected newborns were randomized at 6-14 days postpartum to mART or iNVP. These regimens were continued until 18 months post-delivery, unless breastfeeding was stopped, the infant became HIV-infected, or because of toxicity. Mother-infant pairs (n=2,431) were enrolled between June 2011 and October 2014. Median duration of breastfeeding was 15 months and not significantly different by study arm (p=0.85). K-M estimates of mother-to-child transmission of HIV at ages 6, 9, and 12 months were 0.3 percent (95% CI 0.1-0.6), 0.5 percent (95% CI 0.2-0.8), and 0.6 percent (95% CI 0.4-1.1), respectively, and not significantly different between the two arms. Infant 12-month survival rate was extremely high (98.9%) and not significantly different by regimen. Incidence rates of maternal/infant safety outcomes also did not differ significantly by regimen. Study results show that iNVP throughout breastfeeding is a safe and effective option for HIV-positive mothers who do not adhere to or tolerate ART.

  • Abstract: Comparing Maternal Triple Antiretrovirals (mART) and Infant Nevirapine (iNVP) Prophylaxis for the Prevention of Mother-to-Child Transmission (MTCT) of HIV during Breastfeeding (BF)
  • Session: Treat Early and Stay Suppressed (Session Room 12; Thursday 21 July, 11:00 – 12:30 SAST)

Treatment challenges among HIV+ women after giving birth: Results from two analyses of the largest randomized trial to date (PROMISE) evaluating postpartum antiretroviral therapy for women with high CD4 counts (≥400 cells/mm3) demonstrated an urgent need to increase treatment acceptance and adherence. Judith Currier from the David Geffen School of Medicine discussed results of the PROMISE 1077HS study among women from 52 sites in Argentina, Botswana, Brazil, China, Haiti, Peru, Thailand, and the United States (n=1,652). Women were randomized to continue or discontinue ART. Among the women selected to continue treatment (n=827), nearly one-quarter (23%) had virologic failure. Among a subset of these women who had been tested for drug resistance (n=155), 86 percent did not have resistance to their current regimen, indicating non- adherence led to virologic failure.  A second study (IMPAACT PROMISE), presented by Lynda Stranix-Chibanda of the University of Zimbabwe shared concerning results regarding acceptance of treatment. Among 1,483 HIV-positive women who had recently given birth, about one third (34%) declined to go on treatment, even after being counselled about the benefits of starting treatment regardless of CD4 count. Both studies demonstrate the significant challenges that will need to be addressed to successfully implement WHO’s recommended “treat all” approach. [Summary based on submitted abstract; updated data may be presented on site.]

  • Abstracts: Randomized Trial of Stopping or Continuing ART among Post-partum women with Pre-ART CD4 > 400 cells/mm3 (PROMISE 1077HS) & Low acceptance of early antiretroviral therapy (ART) among post-partum women enrolled in IMPAACT PROMISE Studies across the globe
  • Session: Treat Early and Stay Suppressed (Session Room 12; Thursday 21 July, 11:00 – 12:30 SAST)

New simplified treatment option for HIV+ women: Phase III results from an international, randomized, open-label study (ARIA) among treatment-naïve adult women (n=495) show promising results of a simplified treatment regimen after 48 weeks. Catherine Orrell of the Desmond Tutu HIV Centre presented the trial results, which found that a once-daily fixed dose combination of dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) had superior efficacy and a favourable safety profile compared to a regimen of ritonavir boosted atazanavir plus tenofovir disoproxil fumarate/emtricitabine (ATV+RTV+TDF/FTC). Among women taking the fixed dose combination, 82 percent were virally suppressed (HIV-1 RNA <50 c/mL) compared to 71 percent taking the other regimen (adjusted difference 10.5%, 95% CI: 3.1% to 17.8%, p=0.005). The safety profile of the fixed dose combination treatment was also favourable compared to the other regimen, with fewer drug-related adverse events reported in the DTG/ABC/3TC group. These results provide important information to help guide treatment decisions for women. [Summary based on submitted abstract; updated data may be presented on site.]

  • Abstract: Superior Efficacy of Dolutegravir/Abacavir/Lamivudine (DTG/ABC/3TC) Fixed Dose Combination (FDC) compared with Ritonavir (RTV) Boosted Atazanavir (ATV) plus Tenofovir Disoproxil Fumarate/Emtricitabine (TDF/FTC) in Treatment-Naïve Women with HIV-1 Infection (ARIA Study)
  • Session: Treatment Evolution: New Drugs, New Reality (Session Room 6; Thursday 21 July, 16:30 – 18:00 SAST)