Yesterday, the FDA approved the first-ever drug to prevent infection with HIV, the virus that causes AIDS. The drug, Gilead Sciences Inc.’s Truvada, was approved for use by certain high-risk, uninfected people to help prevent them from contracting HIV. Truvada works by making it harder for the virus to multiply.
What do the experts think of Truvada? We asked Carl Ware, Ph.D., director of Sanford-Burnham’s Infectious and Inflammatory Disease Center, and Sumit Chanda, Ph.D., an associate professor in the Center whose lab studies the complex interactions between host cells and viruses such as HIV.
“This type of drug is long overdue,” Ware says. “It may be the best opportunity to control the virus spread that we have in the absence of the best possible approach—an effective vaccine. Only certain HIV-negative people at high risk for exposure to the virus are supposed to use this new drug, for example the spouse of someone that has HIV. Yet Truvada will limit the spread of the virus, which is important for everyone.”
What about long-term risks?
“Truvada has been on the market since 2004 for treatment of HIV infection, so the FDA had a window of about 10 years of side effect data to look at [before approving the drug for HIV prevention]. There appear to be some liver toxicity and lactic acidosis issues—enough for the FDA to include them in a black-box warning—but it’s generally safe. Truvada has now been approved for prophylactic use in high-risk HIV negative individuals, and these issues should not change,” says Chanda. “HIV-negative individuals will need to consider this and balance against risk of exposure. Longer-term toxicity is certainly an issue, and is definitely an unknown. It’s very likely the FDA will keep a close eye on this going forward, and ensure that the benefits continue to outweigh the risks, especially for those people who do not need it to fight infection, but to prevent it.”
According to Ware, the long-term risks of taking the drug clearly outweigh the consequences of acquiring an HIV infection for the individual. Yet he worries about a different kind of risk—that of complacency. “We don’t want people to think they can use the drug as a ‘morning after pill’,'” he says. “It’s the press’ responsibility to remain vigilant in accurately reporting this advance to the public.”
The World Health Organization estimates that 34 million people worldwide are living with HIV.
Click here to read more Beaker blog posts about Sanford-Burnham’s research on HIV and other infectious diseases.