Tuesday, February 10, 2009

Finally, some good news for women at risk of HIV

Women and girls are the new face of HIV/AIDS. Globally, there are twelve HIV-positive women for every ten HIV-positive men. In the hardest hit countries of sub-Saharan Africa, young women are three times more likely than their male peers to become infected.

The disproportionate impact of HIV on women is due to a variety of biological and socioeconomic factors, factors that also make current HIV prevention tools – including condoms and mutual monogamy – inaccessible to those most at risk. For example, many women do not have the social or economic power necessary to insist on condom use and fidelity, or to abandon partnerships that put them at risk.

Thus, there is a desperate need to develop new user-controlled tools to enable women to protect themselves, such as vaginal microbicides. Over the past two years, a series of flat findings and trial closures have shaken public confidence in research to develop safe and effective microbicides. But now there’s a glimmer of hope.

Yesterday, at the 16th Conference on Retroviruses and Opportunistic Infections in Montreal, a team of researchers funded the US National Institutes of Health announced the results of HPTN 035, a clinical trial of PRO2000 and BufferGel, two candidate vaginal microbicides.

This study enrolled over 3000 at-risk women in Malawi, South Africa, United States, Zambia and Zimbabwe. In addition to showing that these products were safe to use, the study found that women used PRO2000 (as a topically-applied gel) plus condoms had 30% fewer HIV infections than those who used only condoms or condoms plus a placebo gel.

Although the decrease in HIV infections among women using PRO2000 did not quite achieve statistical significance, this is first large-scale clinical trial showing that a candidate microbicide might actually work in women. A second trial of PRO2000, enrolling more than 9000 at-risk women in Southern Africa, is currently underway. The results of that study – known as MDP201 – will be available in November. If the data from the MDP201 trial also show that PRO2000 is safe and effective, it is expected that this gel will be submitted for regulatory review and approval, hopefully giving women worldwide access to a new and sorely needed HIV prevention tool.

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