Anti-H.I.V. Gel Less Magical Than Originally Thought

Despite countless warnings about things that seem to good to be true, we were pretty excited by the news that researchers had developed a vaginal gel that can protect women from HIV (and possibly herpes too). Unfortunately, this weekend there was a major setback. A new trial of the gel was canceled because it doesn't appear to be working.

In 2010, researchers announced that a trial conducted in South Africa found that a gel containing the drug tenofovir protected 39% of the women who used it from contracting HIV, and the number shot up to 54% when women used it more regularly. The New York Times reports that in 2009, another trial called Voice (for Vaginal and Oral Interventions to Control the Epidemic) was launched to confirm the results of the first study. 5,000 women from South Africa, Uganda, and Zimbabwe were involved in a three-part trial that compared the effects of the gel, a tenofovir pill, and another pill containign tenofovir and a booster drug. Several months ago the trial of the tenofovir pill was canceled because it doesn't appear to be working, and now researchers have called off the gel experiment for the same reason.

The researchers' primary aim is to develop a method that will allow women to protect themselves against HIV even if they can't make their partner use a condom. The gel itself isn't dangerous, but an independent review panel found that 6% of the women using the gel and 6% on the placebo have become infected with HIV, and it isn't ethical to allow the participants to continue using a method they know isn't working.

Lead researcher Sharon L. Hillier said she's "surprised and disappointed" by the cancelation. Reports of the high rate of success sparked a lot of hope among AIDS researchers, and this development is particularly frustrating because doctors have no idea why the drug isn't working, and can't even start looking for a solution. The study can't be "unblinded" yet because one of the experiments is still on. It doesn't make sense that a drug that was originally so effective would suddenly stop working, so researcher are hypotehsizing that the problem could be the how often the women were using the gel. Unfortunatlely, they won't be able to come up with any real answers until the results of the study are released in 2013.

Anti-H.I.V. Trial In Africa Canceled Over Failure To Prevent Infection [NYT]

Earlier: New Maybe-Miracle Gel Protects Women From HIV
Magic Anti-HIV Gel May Also Protect Against Herpes

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