Anti-HIV ring shows promise in trial
Clinical trials of an anti-HIV vaginal ring show promise for helping women avoid the virus, especially in sub-Saharan Africa, where an estimated 1,000 women ages 15 to 25 are infected every day. The device functions similarly to contraceptive rings, slowly releasing the antiretroviral drug dapivirine. Women replace it themselves once a month. The ring was tested in trials run by the National Institutes of Health-funded by Microbicide Trials Network and the International Partnership for Microbicides, a nonprofit that developed the ring. Sharon Hillier, principal investigator of the Microbicide Trials Network, is based in Pittsburgh at Magee-Womens Research Institute. Below, Hillier answers questions about the trials.
How were the trials designed?
The trials enrolled 96 young women between 15 and 17 years old who had had sex at least once. They were randomly assigned to use either the dapivirine vaginal ring or a placebo ring, with 73 women assigned to use the dapivirine ring and 23 women to use the placebo.
What are the results of the study?
The study found no differences in safety outcomes between the dapivirine ring and the placebo ring. Forty-two percent of participants said they had never removed the ring except to replace it. In the dapivirine group, 87 percent of plasma samples had detectable levels of drug suggestive of the ring being used the previous day; 95 percent of the rings returned after use had drug levels that suggested regular use during the previous month. Ninety-five percent said the ring was easy to use, and 74 percent indicated they were not aware of the ring during daily activities. Some were worried that their partner would feel it during sex, but overall, 93 percent of participants said they liked the ring.
How are these results important?
The dapivirine ring was shown to be both safe and help protect against HIV in the trials, which together enrolled more than 4,500 women ages 18 to 45. IPM is seeking regulatory approval of the ring for adult women based on the results of these trials and supporting studies. Regulatory authorities could consider expanding approval of the ring to include girls under age 18. Finding the ring safe and well tolerated by U.S. adolescent girls, MTN researchers are now planning a second study, called REACH, that will collect safety data among adolescent girls and young women in Africa, who are among the most vulnerable population at risk of acquiring HIV.