HIV-prevention vaginal ring proves effective in African trial
While condoms and preventative drugsare effective at blocking HIV transmission, for women in developingregions like sub-Saharan Africa, such methods can be too expensive orimpractical for continual use. A new treatment, which providespatients with a more long-term protective solution in the form of adrug-releasing vaginal ring, has proved partially effective in a newstudy.
More than half of the 25.8 millionpeople living with HIV in sub-Saharan Africa are women. The vaginalring, which is central to the US National Institutes of Health-funded ASPIRE study, provides a sustainedrelease of the antiretroviral drug dapivirine, providing a new way of combating the risk of contracting the virus. We've seen very similar devices in the past, including the Northwestern University-developed TDF-IVR. Researchers believethat the technology could make a big difference in preventing transmission of thevirus.
The ASPIRE study, which is also knownas MTN-020, is a collaborative project led by researchers at South Africa's Wits Reproductive Health and HIV Institute, and the University of Washington in Seattle. The team worked to test the effectiveness of the drug-releasing ring, which is designedto be replaced once every four weeks.
The project began in 2012, andsaw more than 2,600 women without HIV take part, with ages rangingfrom 18 to 45 years old. The patients were split into two groups, onereceiving the drug-releasing ring, and one being given a placeboring.
At the end of the study, theresearchers found that the dapivirine ring had reduced transmissionrisk by 27 percent across all women taking part in the study. Butdelving a little deeper into the data revealed that its effectivenesswas likely understated by the research.
For example, once the data from womenat two test sites, where it was obvious to the researchers that theparticipants were not using the ring as consistently as requested,was excluded, the results improved. Under those conditions, the ringwas found to reduce risk of infection by 37 percent.
Looking more closely still, theresearchers noticed that for women aged 25 and older, use of thedevice reduced risk by an impressive 61 percent, but for those under25, it provided no statistically significant protection. Analyzingblood from participants revealed that younger participants weren'tusing the ring as much as older patients, once again suggesting thatthe device, when used properly, reduced risk significantly more thanthe blanket 27 percent figure indicates.
Overall, the ASPIRE study representsthe first practical evidence that sustained drug delivery, as provided bythe ring, can indeed offer significant protection from the risk ofcontracting HIV.
"To help bring about an end tothe HIV/AIDS epidemic, women – especially those in sub-SaharanAfrica – need multiple options for HIV preventions," said studyco-lead Jared Baeten. "The ASPIRE study was an important steptowards determining whether the dapivirine ring could become one suchoption."
The findings of the research arepublished online in the New England Journal of Medicine.