Today the US Food and Drug Administration (FDA) weighed the benefits and risks of what could be the first HIV prevention pill to hit the market. A decision from the FDA is expected June 15.
Scientists on the FDA’s Antiviral Drugs Advisory Committee heard from investigators who led NIH and CDC-sponsored clinical trials on the drug Truvada, as well as doctors, patient advocates, and Gilead Sciences, the drug’s maker. Just before 7pm EST, 19 of the 22 committee members agreed that, despite any risks, Truvada would be useful in preventing HIV for men who have sex with men, and for HIV-negative individuals with HIV-positive partners. Opinions on the drug’s use for other risk groups reflected a greater uncertainty, with 12 members voting in favor of Truvada, 8 voting against it and 2 abstains.
Condoms provide better protection against HIV than Truvada, which was approved for HIV as a therapy in 2004. But Howard Jaffe, president of Gilead, says that the fact that there were more than 48,000 new HIV infections diagnosed in the US in 2010 implies that condoms aren’t enough. In the two largest trials, Truvada reduced participants’ risk by 42% and 73%.
The FDA committee was particularly worried that people taking Truvada as a prophylaxis would develop resistance to the therapy if they unknowingly became infected. Indeed, six of the 11 clinical trial participants who had tested negative when the trials began, but turned out to be HIV-positive when they were tested several weeks later, learned that that Truvada would no longer work for them.
To mitigate this risk, committee members discussed strategies to ensure that people adhere to their daily treatment regiment so that it remains effective. And for more than an hour, the committee and attendees debated over how often patients ought to be tested and how that might be enforced.
“The real risk is that patients will take Truvada inconsistently, get HIV, and then not have Truvada available to them because they’ve developed HIV,” says Wayne Chen, a clinician at the AIDS Healthcare Foundation. “I have qualms about prescribing PrEP [Pre-Exposure Prophylaxis] when there is a safer alternative that does not put a patient at risk.” He adds, “It’s contrary to the Hippocratic oath of doing no harm to the patient.”
If and when Truvada is approved for prevention, Jaffe predicts that countries in Africa and Southeast Asia with a greater burden of HIV infection than the US will soon put the tool to use. Indian manufacturers already produce much of the Truvada sold in Africa for a price far below the $11,000 per year that it costs in the States.