A microbicide gel intended to prevent HIV infection in women, called PRO 2000 (0.5% dose), was 30% effective, according to results from a clinical trial conducted at the University of Pennsylvania School of Medicine and six trial sites in Africa. The results of the study, known as HPTN 035, were presented today at the international Conference on Retroviruses and Opportunistic Infections in Montreal, Canada. This is the first human clinical study to suggest that a microbicide gel may prevent male-to-female sexual transmission of HIV infection.

"We are extremely excited with the results of this trial," stated Glenn L. Cooper, M.D., chairman and chief executive officer of Indevus. "Though not conclusive, these results provide encouragement that PRO 2000 may offer a female-controlled method that can be used to protect against the sexual transmission of HIV.

The researchers tested another microbicide called BufferGel made by ReProtect Inc, but were unable to find any significant indication that it helped. The study was only designed to show the gels were safe; an especially important issue because other studies have shown would-be microbicides actually raised the risk of infection.

Meanwhile, the company said it is waiting for more study data on Pro 2000 in a study involving nearly 10,000 women. Those results should be available by the end of 2009.
Full results from the study will be presented Monday at the 16th Conference on Retroviruses and Opportunistic Infections in Montreal.

Clients who report engaging in recent, high-risk behavior will be invited to take viral RNA (ribonucleic acid) testing, which will identify those who are acutely infected. They will also be encouraged to alert their partners. It takes two weeks to get results. During that time, said Steve Gibson, director of Magnet, clients are counseled to behave prudently, as if they were HIV-positive.