Dapivirine ring can protect women against HIV

A clinical trial involving more than 2,600 women in Africa finds that a vaginal ring containing an antiretroviral (ARV) drug called dapivirine is safe for women and can help to protect them against HIV on a large scale.

The study found the dapivirine ring reduced the risk of HIV infection by 27 percent overall; there were 27 percent fewer women who acquired HIV in the group assigned to use the dapivirine ring than in the group assigned to use a placebo ring containing no active drug.

The risk of HIV was reduced significantly more among the study's older participants, who also used the ring most consistently. Women in the dapivirine group who were 25 and older were 61 percent less likely to acquire HIV than women of the same age in the placebo group.

Intrigued with this finding, the researchers conducted additional analyses. These drew a more precise line of demarcation, with lack of protection being confined to women between the age of 18 and 21, and women older than 21 seeing their risk of HIV cut by more than half (56 percent).

ASPIRE, researchers who conducted the trial, enrolled HIV-negative women ages 18 to 45 at 15 clinical research sites in Malawi, South Africa, Uganda and Zimbabwe.

In the second trial, called 'The Ring Study', HIV risk was reduced by 31 percent overall, and by 37 percent among participants older than 21.

The International Partnership for Microbicides (IPM), which developed the monthly dapivirine ring, is conducting The Ring Study in South Africa and Uganda among 1,959 women.

Although still ongoing, 'The Ring Study' is reporting results early, following a recommendation of its independent data and safety monitoring board that the study proceed to final analysis.

Vaginal rings are flexible products that fit high up inside the vagina where they release a medication slowly over time. They are already used in the United States and Europe to deliver hormonal contraception. Women can insert and remove the ring themselves.

The study has been published in New England Journal of Medicine.