July 25, 2012
Two large clinical HIV-prevention trials in Africa will test the safety and effectiveness of a vaginal ring containing the antiretroviral drug dapivirine. Both studies are being conducted in partnership with the US National Institutes of Health-backed Microbicide Trials Network.
If effective, the ring will add "a long-acting, female-initiated technology to the existing toolkit of HIV prevention options," said Dr. Zelda Rosenberg, CEO of the International Partnership for Microbicides (IPM), a nonprofit group that is developing the ring. Because it only needs to be replaced once a month, the ring may help address some of the problems with getting women to use vaginal gels consistently each time they have sex, Rosenberg said during the 19th International AIDS Conference.
The IPM study will enroll 1,100 women ages 18-45 at four sites in South Africa; they will be randomly assigned to use the ring or a placebo. Researchers plan to expand the trial to Rwanda and Malawi.
The other study, called ASPIRE, will test the ring in 3,476 women ages 18-45 in Malawi, South Africa, Uganda, Zambia, and Zimbabwe.
Dapivirine is part of a class of antiretroviral drugs that have long been used to treat HIV and prevent mother-to-child HIV transmission.
Results are expected in 2015. Both trials are seeking at least a 60 percent reduction in HIV risk, but researchers hope for an even better outcome.
"Because the vaginal ring is a long-acting intervention, it has a potential added benefit in that women may find it relatively easy to use," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Women in the studies will be offered condoms and HIV prevention counseling. Women who become pregnant will discontinue use of the ring and will continue to be monitored.