Truvada Shown to Prevent HIV Transmission


The best prevention of HIV and AIDS remains safe sex practices, but a new study published today in the New England Journal of Medicine reveals that prevention may also become available in the form of a once a day pill.

The multinational study, called the Preexposure Prophylaxis Initiative (iPrEx) trial evaluated the safety and efficacy of the antiretroviral (ARV) drug TDF/FTC (brand name Truvada) taken once daily for HIV prevention among HIV-negative gay men, transgender women, and other men who have sex with men (MSM).

The researchers randomly assigned 2499 HIV-seronegative men or transgender women to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC–TDF), or placebo once daily. Participants included individuals from Peru, Ecuador, Brazil, South Africa, Thailand and the United States.

Enrollment for the trial began in June 2007 and was completed in December 2009. The primary analysis of the results released today includes participants who were followed until May 1, 2010, or for an average of 14 months.


Each participant was tested for HIV at monthly trial visits and given intensive pre-and-post test counseling. Additionally, they were regularly screened for sexually transmitted infections and received condoms, making up a very robust prevention package.

At the end of the trial, there were 44% fewer HIV infections in participants who received Truvada (n = 36) than in participants who who took the placebo (n = 64). There was even more protection noted in the FTC–TDF participants whose blood tests showed they had taken their pill faithfully every day were considered. Only 3 of 34 became HIV-infected or put another way, the pill was more than 90% effective in preventing the infection.

For Truvada to prevent HIV, the pill must be taken regularly. Regular HIV testing and ongoing monitoring by a physician remains critical, as do continued safe sex practices.

Moderate nausea (grade 2 and above) was reported more frequently in the Truvada group than in the placebo group (22 vs. 10 events), as was unintentional weight loss of 5% or more (34 vs. 19 events).

Truvada is available by prescription in many countries right now. In the United States, Truvada, made by Gilead Sciences, costs $12,000 to $14,000 a year. In very poor countries, generic versions costs as little as 40 cents a pill.

Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men; Robert M. Grant, M.D., M.P.H., Javier R. Lama, M.D., M.P.H., Peter L. Anderson, Pharm.D., et al; New England Journal of Medicine, November 23, 2010 (10.1056/NEJMoa1011205)