According to research conducted in 4 African countries, a majority of women were interested in and adhered to the use of a dapivirine vaginal ring to reduce their risk of contracting HIV, according to results of a study conducted by the National Institutes of Health-funded Microbicide Trial Network and reported in a press release.
In the HIV Open-label Prevention Extension (HOPE) study, former participants of the ASPIRE (MTN-020) Phase III trial (N=1456) were given the opportunity to use the antiretroviral (ARV) dapivirine ring for 1 year. Included participants were HIV-negative, neither pregnant nor breastfeeding, and agreed to use contraception during the study. Participants were given the continuous option to select whether or not to accept and use the dapivirine ring throughout the study. To calculate whether they were adherent to the recommended regimen of the ring, the researchers measured the amount of ARV drug remaining in the rings at each visit.
At the beginning of the HOPE trial, 92% of participants accepted the dapivirine ring. At quarterly clinic visits, interest was reevaluated and use of the ring remained high. At 3 months, 87% of women accepted the ring. At 6 months, 83% continued to accept the ring, and at 9 months, 79% of women accepted the ring. Measurements for residual levels of dapivirine at quarterly visits indicated that 90% of participants adhered to using the ring. HIV incidence was 2.7% (n=35 participants).
The study limitations included the inexact methods for measuring residual drug levels to indicate adherence. In addition, as there was no control cohort, and therefore no true placebo group, these results cannot be viewed with the same degree of confidence as in randomized controlled trials.
“We wanted women to know that the decision was theirs to make, and theirs alone. As it turns out, most participants wanted the dapivirine ring — they accepted the ring being offered. And women in HOPE also appeared to use the ring more consistently than they did in ASPIRE,” said Jared Baeten, MD, PhD, professor of global health, medicine and epidemiology at the University of Washington in Seattle, and co-principal investigator of the HOPE study.
The dapivirine ring is currently under regulatory review by the European Medicines Agency in cooperation with the World Health Organization. The monthly dapivirine ring could represent another biomedical option for women seeking to protect themselves from HIV. The Microbicide Trials Network are currently conducting studies to inform potential approval of the dapivirine ring for girls aged ≤18 years and for women during pregnancy and breastfeeding.
Open-label study of a vaginal ring for HIV prevention suggests women want and will use it [news release]. Mexico City, Mexico: Microbicide Trials Network; July 23, 2019. https://medicalxpress.com/news/2019-07-open-label-vaginal-hiv-women.html. Accessed August 15, 2019.