A trial on a microbicidal vaginal gel designed to protect women against HIV infection has been stopped. Sponsored by the US reproductive health organization CONRAD, the trial was stopped because the group of women using the active gel were being infected with HIV at a higher rate than the placebo group.
The cellulose sulfate microbicide gel is one of four currently in a third phase of testing by clinical trials. Trials on the other three products have not been stopped.
The trial was being conducted on over 1,300 women in Benin, India, South Africa and Uganda. Another trial in Nigeria, sponsored by Family Health International, using the same product has also been stopped as a precautionary measure, although there is no news as to whether this trial was giving similar results.
The World Health Organization said today that “This is a disappointing and unexpected setback in the search for a safe and effective microbicide that can be used by women to protect themselves against HIV infection.”
CONRAD, the sponsors of the trial that has been stopped, is a cooperating agency of USAID, whose Chief of Research, Technology and Utilization Division, Office of Population and Reproductive Health, Jeff Spieler, said in a prepared statement that he was “surprised and disappointed by these findings given the pre-clinical effectiveness and safety profile of CS and its safety profile demonstrated in Phase I trials.”
He said he was hopeful that the other three products in Phase III trials would yield good results and help to push forward the fight to help women protect themselves against HIV infection.
The other three microbicide products in Phase III trials are: Carraguard, which is being tested in 3 South African sites and is expected to finish in 2007; PRO 2000, which is being tested in two studies, one due to finish in 2008 and another in 2009, also in a range of African countries. And one of the PRO 2000 studies is also testing the third microbicide, BufferGel.
Apart from BufferGel, which is a vaginal defence enhancer, the other Phase III products, including cellulose sulfate, are known as HIV entry inhibitors – they block the infection route for HIV.
The cellulose sulfate microbicide gel in the trial that has been stopped is manufactured by the Canadian company Polydex Pharmaceuticals.
Microbicides are a range of products for use by women. Each product acts in its own way to reduce the transmission of HIV by sexual intercourse. The products are available in a range of forms such as gels, creams, tablets, sponges, films, or in a vaginal ring that releases the agent over a period of time.
They are considered an effective route for HIV prevention because studies show that significant numbers of African men will not use condoms for a range of reasons and women are not able to insist that they do.
Click here for cellulose sulfate microbicide Clinical Trial Summary (CONRAD site).
Click here for more information on microbicides (Alliance for Microbicide Development).
Written by: Catharine Paddock
Writer: Medical News Today