July 25, 2012

Just-Approved Prophylaxis Agent Opens New Front in HIV War

Foster City, CA—The FDA has opened a new front in the war against human immunodeficiency virus (HIV) with approval of emtricitabine/tenofovir disoproxil fumarate to be used for pre-exposure prophylaxis (PrEP) in uninfected individuals.

It is the first drug approved to reduce the risk of HIV infection in those who are at high risk of HIV infection and who may engage in sexual activity with HIV-infected partners. The FDA is urging that the once-daily oral drug, marketed as Truvada, be used in combination with safer sex practices, risk reduction counseling, and other prevention measures to reduce the risk of sexually-acquired HIV infection in adults at high risk.

Truvada, from Gilead Sciences, Inc. of Foster City, California, previously was approved for use in combination with other antiretroviral agents for the treatment of HIV-infected adults and children older than 12.

"Today’s approval marks an important milestone in our fight against HIV," said FDA Commissioner Margaret A. Hamburg, MD. "Every year, about 50,000 U.S. adults and adolescents are diagnosed with HIV infection, despite the availability of prevention methods and strategies to educate, test, and care for people living with the disease. New treatments as well as prevention methods are needed to fight the HIV epidemic in this country."

Detailed U.S. Public Health Service guidelines on using Truvada for PrEP will not be published until later this year, according to a statement from the CDC, which emphasized that while the new drug can be an important prevention tool, it must be part of a larger initiative, including counseling on medication adherence.

According to a stronger boxed warning on Truvada for PrEP, the FDA cautions that use of the drug must be limited to individuals who are confirmed to be HIV-negative prior to prescribing the drug and at least every 3 months during use. The agency strongly recommends against prophylaxis when HIV status is either positive or unknown.

As part of the approval, Gilead worked with the FDA to develop a Risk Evaluation and Mitigation Strategy (REMS) to help ensure safe use of Truvada for PrEP.

"The REMS for Truvada for the PrEP indication is aimed at educating health care professionals and uninfected individuals to help ensure its safe use for this indication without placing an unnecessary burden on health care professionals and patients," said Janet Woodcock, MD, director of the FDA’s Center for Drug Evaluation and Research.

Two large, randomized, double-blind, placebo-controlled clinical trials demonstrated Truvada’s effectiveness for PrEP. One, the iPrEx trial, evaluated the drug in 2,499 HIV-negative men or transgender women who have sex with men and who evidenced high-risk behavior for HIV infection; results demonstrated that Truvada reduced the risk of HIV infection by 42% compared to placebo. The Partners PrEP trial involved 4,758 heterosexual couples where one partner was HIV-infected and the other was not. Truvada reduced the risk of becoming infected by 75%, compared with placebo, according to those results.

The most common side effects reported with Truvada included diarrhea, nausea, abdominal pain, headache, and weight loss. Overall, serious adverse events were uncommon.

Research is continuing, with Gilead agreeing as a condition of approval to collect viral isolates from those who acquire HIV while taking Truvada and to evaluate these isolates for the presence of resistance. Data on women who become pregnant while taking Truvada for PrEP also is being collected.

Overall drug adherence information gathered by Gilead will be provided to prescribers to help them identify patients who are unlikely to comply with the drug regimen.

U.S. Pharmacist Social Connect