Two large clinical trials in Africa are ramping up to test the effectiveness of a vaginal ring that releases an HIV-fighting drug for a month or more, offering women at high risk a discreet way to protect themselves from the virus that causes AIDS.
The studies will test the effectiveness of a vaginal ring containing the antiretroviral drug dapivirine in thousands of women in several African countries to evaluate its ability to prevent new HIV infections and its long-term safety.
If effective, the ring will add "a long-acting, female-initiated technology to the existing toolkit of HIV prevention options," said Dr. Zeda Rosenberg, chief executive officer of International Partnership for Microbicides (IPM), a nonprofit group founded by Rosenberg which 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 consistently use vaginal gels each time they have sex, Rosenberg said during a briefing at the International AIDS Conference in Washington. For full coverage of the meeting, see:
Irregular use is thought to be the reason a large study of the microbicidal gel containing the anti- HIV drug tenofovir failed to prevent infections in women in sub-Saharan Africa.
IPM has a royalty-free licensing agreement with Johnson & Johnson's Janssen unit in Ireland to use its dapivirine antiretroviral product in gel and ring forms to prevent HIV infections in low and middle income countries.
Dapivirine is part of a class of antiretroviral drugs that have long been used to treat HIV and prevent mother-to-child transmission of the virus.
The IPM study will enroll 1,650 women aged 18 to 45, who will be randomly assigned to use the ring or a placebo in four sites in South Africa, with, plans to expand to sites in Rwanda and Malawi.
It is being conducted in partnership with the U.S. National Institutes of Health-backed Microbicide Trials Network, which just started enrolling women in a separate trial called ASPIRE.
"Developing scientifically proven forms of HIV prevention that women can control is essential," said Dr. Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Disease.
"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."