Two further clinical trials are planned for a vaginal gel that has shown potential in reducing the risk of HIV and which, if confirmed, would be a major breakthrough in protecting women, who make up about half of the people living with the virus worldwide, the United Nations said today.
The results of the first trial of the tenofovir-based gel, which were announced in July at the XVIII International AIDS Conference in Vienna, must be confirmed before the product can be made available for general use.
The gel was found to be 39 per cent effective in reducing a women’s risk of HIV infection during sex in a study completed by the Centre for the AIDS Programme of Research in South Africa (CAPRISA), a collaborative partner of the Joint UN Programme on HIV/AIDS (UNAIDS).
At a meeting convened last week in Johannesburg, South Africa, by UNAIDS and the World Health Organization (WHO), experts proposed that further trials should determine whether different populations of women will have the same level of protection as seen in the CAPRISA trial.
The CAPRISA study was conducted in South Africa with women aged 18 to 40 years who used the gel once during the 12 hours before sex and once during the 12 hours after sex, according to a news release issued by UNAIDS.
One of the next two studies will also take place in South Africa, and determine if the CAPRISA results can be repeated in a variety of settings with a population that includes younger women.
It will also evaluate whether the gel can be used safely by sexually active 16- and 17-year-olds in settings where HIV incidence is high.
The other study will be conducted in other African countries and examine if a different dosing schedule is safe and effective. It will test if a single application of the gel before sex, or failing that immediately after, is equally effective and safe as the original two-dose regimen.
While participants at the Johannesburg meeting agreed on research priorities, they expressed concerns over the limited funding committed for the next phase of research. Only $58 million of the estimated $100 million needed is so far available.
“This promising tenofovir gel is a woman-initiated and controlled HIV prevention tool that could now be within reach,” said Catherine Hankins, Chief Scientific Adviser to UNAIDS.
“Funders, advocates, and scientists can work together to close the funding gap rapidly, gather the evidence, and ensure that no time is lost in getting a safe and effective microbicide to women.”