Following the recommendation of the Antiviral Drugs Advisory Committee made on May 10, the FDA approved the medication generically known as combination emtricitabine/tenofovir disoproxil fumarate (FTC/TDF, branded as Truvada®), for HIV prophylaxis for people who test HIV negative. Truvada® is manufactured by Gilead Sciences Inc. in Foster City, Calif., and is currently prescribed with other HIV drugs for treatment of those infected with the virus.
In evaluating whether to allow Truvada® to be prescribed for HIV prevention purposes for those who are not HIV infected, the FDA reviewed the evidence from two studies – the largest of which was conducted by the University of Washington’s International Clinical Research Center (ICRC).
The study, known as the Partners PrEP Study (PrEP is short for pre-exposure prophylaxis), is led by the UW’s International Clinical Research Center. Nine research sites in Kenya and Uganda enrolled 4,758 serodiscordant heterosexual couples, in which one partner has HIV and the other does not, and followed them monthly for up to three years.
The Partners PrEP Study is the largest study of its kind to date and found that FTC/TDF reduced the chances of HIV transmission by 75 percent. Not surprisingly, the protective effect was higher when the drug was taken regularly, without missing doses when analyses considered whether participants had detectable levels of the medication in their blood, the protective effect was approximately 9) percent. Results of the study were published July 11 in The New England Journal of Medicine.
“HIV serodiscordant couples recognized their risk, were highly motivated to take PrEP, and the medication offered high levels of protection for both women and men,” said Dr. Connie Celum, director of the ICRC and a UW professor of global health.
Dr. Jared Baeten, co-chair and medical director for the study and an associate professor of global health at UW, said that the approval of Truvada for use in non-infected people would be a milestone for HIV prevention.
“With the ongoing AIDS epidemic in Africa and the steady number of HIV infections in the United States, it is imperative to determine how this effective prevention strategy can be made available to those at greatest risk worldwide,” said Baeten.
An estimated 7,400 people are infected every day with HIV, according to UNAIDS . More than 60 million have been infected with HIV since the pandemic began. In the United States, new infections have remained steady at 50,000 a year.
In Africa, AIDS is the leading cause of death and HIV discordance in couples is very common, said Celum. She added, “Studies in Africa have found that the partner of an HIV-infected person has about a 50 percent chance of being infected. Finding new strategies to reduce the risk of HIV transmission in HIV serodiscordant couples is a high public health priority.”
The FDA approval is central to United States-based prescribing laws, but the approval can be a strong signal to regulatory bodies around the globe that FTC/TDF for HIV prophylaxis is safe and effective. CDC and WHO guidance are currently being finalized.
The medication used in the Partners PrEP Study, combination emtricitabine (200 mg) / tenofovir disoproxil fumarate (300 mg), is marketed by Gilead Sciences, Inc. under the brand name Truvada®. The medication is available generically in many countries at prices as low as approximately 25-30 cents (USD) per tablet. Gilead Sciences donated study medication, but did not provide funding or otherwise participate in the design, implementation, or analysis of the Partners PrEP Study. The Bill & Melinda Gates Foundation funded the study.