HIV treatment drug could prevent new infections
AIDS vaccine, aids human trials, Dr. Chil-Yong Kang, University of Western Ontario
Published Thursday, May 10, 2012 8:32PM EDT
A pill that has been used to treat HIV may gain approval to become the first drug to prevent HIV infection in healthy people, after a vote by the Food and Drug Administration on Thursday.
The drug, called Truvada, was described by an expert panel at the FDA as being safe and effective in the prevention of HIV. The panel stated that taking the pill daily could spare patients "infection with a serious and life-threatening illness that requires lifelong treatment."
HIV is the virus that, if untreated, develops into AIDS. Many drugs, including Truvada, are currently used to manage HIV, but a cure has not yet been found.
If the drug is approved, it would represent a major breakthrough in the 30-year fight against the AIDS epidemic. According to the United Nation estimates, in 2011 there were approximately 34 million people living with HIV worldwide.
Truvada is already commonly prescribed to people living with HIV. Pending approval from the FDA, the drug could be given to people at high risk of contracting the virus in an effort to prevent them from acquiring the disease.
In an interview with CTV News Channel, Dr. Mark Weinberg, director of the McGill University AIDS Centre, outlined current research showing Truvada's effectiveness.
Clinical trial results showed that among gay men at risk of acquiring HIV, in the group who took Truvada before exposure there was approximately a 44 per cent reduction in the number of new infections, said Weinberg.
Among those who were meticulous in their adherence to the drug regimen, the reduction was closer to 75 per cent.
"That's really a fantastic result," said Weinberg.
Weinberg is involved in a Canadian research study that would prescribe Truvada to people just before they have sexual intercourse and for two days following intercourse.
If successful, his study would have two important implications for people at risk of acquiring the virus: 1) it would require less frequent doses and therefore cut costs for the patient and 2) it would bring down the level of toxicity associated with taking the drug, he said.
"If we can show that use of this regimen was protective, even if used just once, twice or three times a week, that would have significant ramifications in regards to long term toxicities," he said.
While patient advocacy groups say the drug is an important new option to prevent the virus, some researchers have concerns.
Among them is the concern that if Truvada is approved, condom use will decrease, as people will think they are protected by taking the drug.
Using condoms is currently the most effective way of preventing the spread of HIV.
Weinberg responded to this concern by stressing that "We should keep blaring the condom message loud and clear."
However, Weinberg believes Truvada will be effective in the portion of the population that is "simply not listening to the condom message."
"The point of the fact is that in Canada and the U.S. at the present time, there are far, far too many cases of new HIV infections," he said. "If people aren't going to be using condoms they should try this pill approach."
Also of concern is the cost of the drug. Although the FDA is legally barred from considering cost when reviewing drugs, some health care providers have raised concerns over Truvada's price tag: $900 a month, or just under $11,000 per year.
Experts, including Weinberg, believe the FDA will approve Truvada for preventative use on Thursday.