The New York Times examines several products being studied in clinical trials that researchers hope will one day prevent sexual transmission of HIV. The newspaper describes the ongoing trials of a vaginal microbicide gel containing the antiretroviral tenofovir which was found to reduce the risk of HIV infection in women by 39 percent, writing, “[o]ther clinical trials will report their results in 2011 and 2012 and, if all goes well, researchers hope to have a product or two ready to enter the market by 2013.”

Researchers are also anticipating what Mitchell Warren of the Global Advocacy for HIV Prevention describes as “a cascade of results” coming out of clinical trials of “oral pre-exposure prophylaxis” (PrEP). “In them, men and women who are not infected with [HIV] but who regularly engage in high-risk sex, like anal sex without condoms or sex for money with strangers, take a daily dose of one or two of the antiretroviral drugs normally taken by infected people,” the New York Times writes. “If many fewer of those subjects become infected than subjects taking a placebo,” the newspaper writes, “a second breakthrough will have been achieved. … Should that happen, regulatory authorities may approve pills faster than a gel, because they have already been found safe and effective for treatment.”

The article examines some of the advantages vaginal microbicide gels have over PrEP. “The drug in them stays in the vaginal tissue, so it is unlikely that anyone who gets infected anyway would develop a drug-resistant form of the virus. And unlike pills, gels also protect against herpes,” the newspaper writes.

The piece also describes researchers’ work to develop rectal microbicides, which Ian McGowan, who is leading trials at the University of Pittsburgh medical school, describes as being “10 years behind the vaginal one.” The article elaborates on several challenges to the development of a viable a rectal microbicide and notes an upcoming trial of “a vaginal ring containing the new antiretroviral drug, dapivirine. Dapivirine was never approved as a pill because the body doesn’t absorb it well, but it can build up in vaginal tissue.”

The story also includes comments by Sharon Hillier of the University of Pittsburgh’s medical school, who is the principal investigator of the Microbicide Trials Network, and Salim Abdool Karim, of the University of KwaZulu-Natal in South Africa, who co-led the vaginal microbicide gel trial (McNeil, 11/8).