Vaginal Microbicides May Benefit Men More Than Women

Vaginal microbicides currently in clinical trials may be the only weapon that will protect women against infection from HIV. Yet, under likely circumstances, these microbicides may be of more benefit to men than women, according to a new UCLA AIDS Institute study.

The study, which used novel mathematical models to simulate clinical trials and population-level transmission of HIV, appears July 7 in the online issue of Proceedings of the National Academy of Sciences.

“At the moment, there is absolutely nothing that women can do to protect themselves from HIV —condoms are not in women’s control,” said senior study author Sally Blower, professor of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA and a member of the UCLA AIDS Institute. “Drug companies are developing vaginal microbicides to provide direct protection to women and basically empower them so women have some preventive measure that’s under their control.”

Microbicides are compounds that can be applied inside the vagina to protect against HIV and other sexually transmitted diseases. Pharmaceutical companies are currently conducting trials of second-generation microbicides that are based on antiretroviral, or ARV, drugs, Blower noted.

The UCLA study raises concerns that microbicides could lead to drug resistance if they are used by HIV-positive women and that this risk may be masked under current clinical trial designs — necessitating significant caution if the microbicides are licensed for use by the general public.

The researchers developed the mathematical models to determine if ARV-based microbicides that could cause moderate to high levels of drug resistance might pass clinical trials. They used epidemiological, clinical and behavioral data to construct models for both clinical trials and heterosexual transmission of HIV.

The models were based on the Phase 3 clinical trial for second-generation microbicides now under way in South Africa, Tanzania, Rwanda and Belgium. This trial is a 12-month, placebo-controlled study involving 10,000 participants.

The researchers developed simulations for two scenarios: one for high-risk microbicides, in which there is a high probability that the vagina will absorb dapivirine, the ARV drug in the microbicide; the other for low-risk microbicides, with a low probability of absorption. The team created the two scenarios because it is not currently known if ARV-based microbicides will be low- or high-risk.

This entry was posted on Thursday, October 28th, 2010 at 10:11 am and is filed under Impotence.
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