Vaginal ring protects women from HIV
A vaginal ring that continuously releases an antiretroviral drug protected women against HIV in Sub-Saharan Africa. The ring reduced HIV infection by 27 percent in the study population overall and by 61 percent among women ages 25 years and older, who used the ring most consistently.
These results were announced today at the Conference on Retroviruses and Opportunistic Infections (CROI) in Boston and simultaneously published online in the New England Journal of Medicine.
The study, also known as MTN-020, aimed to determine whether the experimental antiretroviral drug dapivirine could safely and effectively prevent HIV infection when continuously released in the vagina from a silicone ring replaced once every 4 weeks. The study, which began in 2012, enrolled more than 2,600 HIV-uninfected women ages 18 to 45 years who were at high risk for HIV infection at 15 sites in Malawi, South Africa, Uganda and Zimbabwe. The women were assigned at random to receive either the dapivirine ring or a placebo ring. No one knew who received which ring until the end of the trial.
The investigators found that the dapivirine ring reduced the risk of acquiring HIV by 27 percent among all women enrolled in the trial. But when the scientists excluded data from two sites where it was apparent early on that many women were not returning for study visits or using the ring consistently, the ring reduced the risk of HIV infection by 37 percent.
Furthermore, the investigators found that the dapivirine ring reduced the risk of HIV infection by 61 percent in women ages 25 and older, but provided no statistically significant protection in women younger than 25 years. These younger women appeared to use the ring less consistently than other participants, based on the amount of dapivirine measured in volunteers’ blood during study visits.
“The study is the first to demonstrate that a sustained drug delivery product that slowly releases an antiretroviral drug over time can offer partial protection from HIV,” added Thesla Palanee-Phillips, Ph.D., who led the study with Dr. Baeten. Dr. Palanee-Phillips is the director of network trials and research center programs at the Wits Reproductive Health and HIV Institute in Johannesburg, South Africa.
