South African Trial of HIV Drug Disappoints

Results from a large-scale trial of a microbicide aimed at curbing the spread of AIDS among women showed the seaweed-derived gel ?was safe, but not effective against HIV transmission,? principle investigator Khatija Ahmed said Monday.

The study was carried out among 6,200 volunteers in South Africa. It was the first major trial of a microbicide to be completed, since earlier or smaller studies of such products had to be halted when evidence showed that not only were they not working, they may have increased the risk for HIV infection.

Half of the South African women received the active ingredient Carraguard, while the control group received an inert material of the same look and texture. Laboratory studies had shown that when inserted vaginally, Carraguard could protect against HIV. But in tests that lasted up to three years, researchers found 134 infections in the Carraguard group and 151 in the placebo group -- a statistical dead heat.

The investigators will look into possible reasons for the disappointing results, including evidence that study women did not use the gel consistently. Study results showed women used it only 44 percent of the time they had sex. ?That overall number is low, and it could have had an impact,? said Barbara Friedland, a researcher at Population Council who coordinated behavioral studies in the trial. The New York-based nonprofit carried out the study with funding from the Bill & Melinda Gates Foundation and the U.S. Agency for International Development.

Because Carraguard proved safe, it could be used in future studies that add antiviral drugs to the gel. ?We will be developing the next generation of products using Carraguard as a base,? said Robin Maguire, director of product development for the council.

Back to other news for February 2008

Search the Newsroom archive