New drug from Gilead may prevent HIV infection, study finds

NEW YORK A daily dose of an anti-retroviral pill appears to prevent HIV infection, according to results of a study conducted by University of California at San Francisco researchers, published in The New England Journal of Medicine on Tuesday.

The study, called “iPrEx,” evaluated the effects of pre-exposure prophylaxis, or PrEP, in 2,499 HIV-negative gay and bisexual men and transgender women who have sex with men and who were considered to be at high risk of infection, administering either Gilead Sciences’ pill Truvada (emtricitabine and tenofovir) or placebo and offering monitoring and counseling on reduction of risky behavior, including use of condoms. At the end of the three-year trial, 36 participants who took Truvada contracted the virus, compared with 64 who took placebo, meaning the risk of contracting the virus was reduced by 43.8% in the treatment group.

As part of the program, patients took the pill on a regular basis while receiving monitoring and counseling to reduce risky sexual behavior. The greatest benefit was observed among those who combined the drug with condoms and other preventive methods.

“It’s a result that requires immediate action,” said Mitchell Warren, director of AIDS advocacy group AVAC. “Because the pill evaluated in iPrEx is licensed and available as treatment for HIV-positive people, gay men and others at risk of HIV need immediate information about what these data tell us and what questions remain.”