Experimental Anti-HIV Gel Proved Safe for Women

Researchers in the United States and India have developed a vaginal gel that is safe for women to use on a daily basis to prevent HIV infection. The world’s first microbicide gel, that has an anti-retroviral (ARV) drug as its active ingredient, has passed the safety test.

The good news has come after last week’s downswing when researchers announced that the first prototype to complete advanced clinical trials was ineffective in preventing infection.

There is neither a cure for AIDS nor a vaccine to prevent the disease. Scientists find in Microbicides, an interesting avenue in the war on AIDS. Microbicides are products, such as gels or creams that could be applied vaginally to prevent HIV transmission.

Women are physically more at risk from AIDS infection than men. Prevention of AIDS currently depends on the use of condoms or abstinence.

The study involved 200 sexually active, HIV-negative women in New York and Pune, India, who were asked to apply the gel either daily or before intercourse for a period of six months. They were also asked to use condoms in addition to the gel.

There was no sign of disruption of liver, blood or kidney function and the researchers found that the women were willing to use it on a continuous basis if it was proved effective in preventing AIDS.

"Based on what we have learned we can proceed with greater confidence on a path that will answer whether tenofovir gel and other gels with HIV-specific compounds will be able to prevent sexual transmission of HIV in women when other approaches have failed to do so," said lead investigator Sharon Hillier, director of reproductive infectious diseases at the University of Pittsburg School of Medicine.

Scientists at National Aids Research Institute, Pune, who have been conducting phase-II trials of Tenofovir gel to look at its safety and acceptability, said, "the overall safety profile of the vaginal gel is good." The study began in August 2006 and was completed by September 2007.

Dr Smita Joshi of NARI and Dr Sharon Hillier, principal investigator for the Microbicide Trials Network, made this announcement at Microbicides 2008 — the biannual international conference in Delhi that discussed the latest development in Microbicides.

Tenofovir gel is an advanced second-generation HIV-specific microbicide that has a double advantage in tackling AIDS. It does not try to kill the AIDS virus or block HIV from entering the body as the earlier microbides tried to do. Instead, it is designed to prevent the HIV virus from replicating when the virus comes in contact with an uninfected T-cell. The virus will not survive long enough to cause systemic infection. The other significant advantage is that it has a long intracellular half-life.

Developing microbicides was on the top of its priority list and they will be developed in the earliest possible time to prevent transmission of STDs and HIV/AIDS to women, according to India’s Union Health Minister Dr.Anbumani Ramadoss.

"Microbicides are still in research process. We are expecting vaccines (to prevent HIV/AIDS) to come out early but it will take some more time. Experts say that microbicides will come early," Dr.Anbumani Ramadoss said here today on the sidelines of Microbicides 2008 conference.

"At the moment 50 experimental substances as possible Vaginal microbicides are being examined and about quarter of these agents are at various stages of human testing and four of these are in advanced stages of clinical trials," he said.

The global figures for 2006 show that estimated HIV/AIDS cases are 39.5 million, out of which 48 per cent are women. In India, estimated HIV/AIDS cases are 2.5 million, out of which 39 per cent are women.

Source-Medindia
THK/K