An ongoing trial to develop a vaginal ring-based microbicide to prevent HIV among women has been found to be safe for use. However, a scientist who is part of the study, said its efficacy will only be established at the end of the trial period.
The trial, titled “A Study to Prevent Infection with a Ring for External Use (ASPIRE),” was started in 2013 and is being conducted in 15 sites in Uganda, South Africa, Zimbabwe and Malawi.
“So far, the ring has been found to be safe. We are closing the follow-up of the participants, which we hope to conclude by July so that we analyse the data,” said Clemensia Nakabiito, the principal investigator of the Uganda trial site at the Makerere University-Johns Hopkins University Research Collaboration Centre.
A total of 2,629 HIV-negative women from the four countries of between the ages of 18 and 45 are currently enrolled in the trial.
Developed by the International Partnership for Microbicides, scientists are testing if the vaginal ring containing the antiretroviral drug dapirivine can offer protection against HIV for women who wear it. The women were randomly given the dapirivine or placebo ring.
The ring is designed in a way that a woman can insert and remove it on her own without the help of a health worker. Dr Nakabiito said once placed inside the vagina, the ring slowly releases dapivirine during the four weeks when a woman is wearing it.
Dapivirine is a highly potent ARV drug known as a non-nucleoside reverse transcriptase inhibitor (NNRTI). As an NNRTI, dapivirine works by preventing HIV from replicating its genetic material after the virus enters a healthy cell.
According to the Microbicides Trials Network, the dapivirine ring is the first long-acting ARV-based product to enter efficacy testing and the first involving an ARV other than tenofovir or a tenofovir combination. Tenofovir is the most commonly used antiretroviral drug.