Breakthrough research shows Gilead antiretroviral Truvada can prevent HIV in men who have sex with men

In a significant advance in the search for HIV prevention, a clinical trial confirms that the same drugs used for treating HIV can also help prevent HIV infection in the first place. The study, known as iPrEx, is important because it gives credence to an HIV prevention approach called oral pre-exposure prophylaxis (PrEP), which involves the use of antiretrovirals (ARVs) by people who are HIV-negative and at high risk of infection.

This is the first of five large-scale effectiveness trials testing oral PrEP to report results, which were published on-line in the New England Journal of Medicine yesterday. Other PrEP trials are ongoing. Results from studies among heterosexuals in Africa and injection drug users in Thailand are expected next year.

The results represent a major boost in efforts to combat HIV worldwide, say researchers from the Microbicide Trials Network (MTN), which is conducting VOICE, an ongoing study of both oral PrEP and a vaginal microbicide. Yet, as a trial involving one particular high-risk group - men who have sex with men - the iPrEx findings cannot be viewed as wholesale endorsement for the widespread use of PrEP at this time, they caution. Until other studies are completed, definitive conclusions cannot be made about how PrEP should or should not be used and in whom it would be safe and effective.