/ 18 February 2008

Microbicide trial failure deals blow to Aids war

An anti-Aids gel that had reached the final phase of testing was unable to prevent the transmission of HIV, research NGO and non-profit organisation the Population Council said on Monday.

It said the third phase of the clinical trials into the product found it ineffective in preventing male-to-female HIV transmission during vaginal intercourse.

”We are disappointed that this trial did not show Carraguard to be effective; nonetheless, the completion of this trial is a milestone in HIV-prevention research,” said Population Council president Peter Donaldson.

He said the trial has contributed to knowledge of product development, trial design, and women and their partner’s willingness to use the gel consistently.

Carraguard is an odourless, tasteless and clear gel made from carrageenan, a derivative of seaweed.

The trial was part of the council’s research into creating vaginal microbicides to develop female-initiated methods for reducing male-to-female transmission of HIV and possibly other sexually transmitted infections.

”Women need more options to protect themselves from infection because current prevention strategies are not always feasible,” said the council. ”The … study found that there were no safety-related differences between women using Carraguard and women using the placebo, and that gel-related side effects were minor and infrequent.”

The Carraguard trial started in March 2004 and ended in March 2007. A total of 6 202 women in South Africa took part at three different sites. These were the Setshaba Research Centre, through the University of Limpopo’s Medunsa campus; the Empilisweni Centre for Wellness Studies, through the University of Cape Town; and the Isipingo Clinic, through the Medical Research Council of South Africa.

Researchers found that there was an incidence of 3,3 new infections per 100 women using Carraguard. A test group given a placebo gel had an incidence of 3,7 infections per 100 women.

The differences between the two groups were not statistically significant. Both groups were also given condoms.

Previous laboratory research had shown Carraguard to be effective in blocking cells from becoming infected by HIV. It had protected mice from some other sexually transmitted infections.

Earlier clinical trials using the product and other similar carrageenan formulations had taken place in Australia, Chile, the Dominican Republic, Finland, South Africa, Thailand and the United States.

Participants in the study received HIV education and counselling, gynaecological exams, and testing and treatment for curable sexually transmitted infections. Women who were HIV-positive at screening or who became HIV-positive during the trial were given medical and psychological assistance.

The trial was funded by the US Agency for International Development and the Bill and Melinda Gates Foundation.

”The Population Council will use these trial results to accelerate the development of effective means for women to protect themselves against HIV,” said the director of the council’s HIV and Aids programme, Naomi Rutenberg. — Sapa