Tenofovir (Viread) Halves HIV Risk in Intravenous Drug Users
Researchers recommend pre-exposure prophylaxis (June 13)
In a new study published in The Lancet, pre-exposure prophylaxis with oral tenofovir (Viread; Gilead Sciences), a commonly used antiretroviral agent, helped cut the risk of human immunodeficiency virus (HIV) infection by nearly half in intravenous (IV) drug users.
The phase III trial enrolled more than 2,000 volunteers from drug treatment clinics in Bangkok, Thailand, between June 2005 and July 2010. The participants were aged 20 to 60 years, were HIV-negative, and reported injecting drugs during the previous year.
The researchers randomly assigned the volunteers to receive either tenofovir (n = 1,204) or placebo (n = 1,209). The volunteers could choose between daily directly observed treatment or monthly visits and could switch at monthly visits. The study’s primary efficacy endpoint was HIV infection.
Fifty participants became infected during follow-up: 17 in the tenofovir group (an incidence of 0.35 per 100 person-years) and 33 in the placebo group (0.68 per 100 person-years), indicating a 48.9% reduction in HIV incidence (P = 0.01). Volunteers who took tenofovir at least 71% of the time had a 74% lower risk of becoming infected.The investigators concluded that pre-exposure prophylaxis with tenofovir may be considered for use as part of an HIV prevention package for injecting drug users.
Based on these results, the Centers for Disease Control and Prevention (CDC) plans to recommend that U.S. doctors who wish to prescribe tenofovir for their patients follow the same interim guidelines issued last year to prevent sexual transmission among other high-risk individuals.