Anti-HIV gel shows promise in Aids prevention

Washington, Feb 10 (ANI): In the first human clinical trial of its kind, a vaginal gel intended to prevent HIV infection in women has shown promise in fighting against the infection.

Called PRO 2000 (Indevus Pharmaceuticals, Inc., Lexington, Mass.), the microbicide gel was found to be safe and approximately 30 percent effective.

A microbicide is a gel, foam or cream intended to prevent the sexual transmission of HIV and other sexually transmitted infections is applied topically inside the vagina or rectum.

The clinical trial, which enrolled more than 3,000 women and conducted in Africa and the United States, suggested that PRO 2000 might prevent male-to-female sexual transmission of HIV infection.

"Although more data are needed to conclusively determine whether PRO 2000 protects women from HIV infection, the results of this study are encouraging," said NIAID Director Anthony S. Fauci, M.D.

He added: "An effective microbicide would be a valuable tool that women could use to protect themselves against HIV and one that could substantially reduce the number of new HIV infections worldwide."

"The study, while not conclusive, provides a glimmer of hope to millions of women at risk for HIV, especially young women in Africa. It provides the first signal that a microbicide gel may be able to protect women from HIV infection," said lead investigator Salim S. Abdool Karim, MBChB, Ph.D., from the Center for the AIDS Program of Research in South Africa.

Mostly, women become infected with HIV through sexual intercourse with an infected male partner. An effective microbicide could provide women with an HIV prevention method they initiate.

This would be particularly helpful in situations where it is difficult or impossible for women to refuse sex or negotiate condom use with their male partners.

The study, known as HPTN 035, began in 2005 and enrolled 3,099 women at six sites in Africa and one in the United States.

The clinical trial tested two candidate microbicide gels for safety and their ability to prevent HIV infection: PRO 2000 (0.5 percent dose), and BufferGel (ReProtect Inc., Baltimore).

PRO 2000 inhibits the entry of HIV into cells; BufferGel boosts the natural acidity of the vagina in the presence of seminal fluid, which can help to inactivate HIV and other pathogens.

In the final analysis, 194 women in the study became infected with HIV. Of these infections, 36 occurred in the PRO 2000 group, 54 in the BufferGel group, 51 in the placebo group and 53 in those who did not use gel.

Based on these data, PRO 2000 was 30 percent effective, while BufferGel had no detectable preventive effect on HIV infection. Both PRO 2000 and BufferGel were found to be safe.

Findings of the study were presented at the Conference on Retroviruses and Opportunistic Infections in Montreal. (ANI)