- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
Promising HIV Strategy Falls Short
19 April 2011 2:08 pm
A large-scale study of a promising drug strategy to prevent HIV infection came to an abrupt end this week when an interim analysis revealed no difference between the experimental and control groups.
The study, which began in July 2009 and involved nearly 2000 women in South Africa, Tanzania, and Kenya who were at high risk of HIV infection, tested whether daily use of Truvada, a pill that contains two antiretroviral drugs, could thwart transmission via heterosexual sex. Given last year's celebrated finding that such pre-exposure prophylaxis (PrEP) stymies the virus in men who have sex with men, many expected this so-called FEM-PrEP study to succeed. An earlier study of one of the compounds in Truvada mixed with a vaginal gel had also found that it could prevent transmission when applied topically.
FHI, a nonprofit organization based in Durham, North Carolina, formerly known as Family Health International, ran FEM-PrEP and pulled the plug after independent observers determined the trial would not have the statistical power to demonstrate Truvada's effectiveness even if it were completed. FHI's Timothy Mastro, vice president for health and development sciences, suspects the "surprising and disappointing" results could be due to a combination of the drug not reaching the vaginal tissue and women not taking pills correctly.
In all, 56 women became infected during the study, half of whom received the drug and half a placebo. Women in the Truvada arm of the trial reported taking their pills 95% of the time, but earlier trials that analyzed blood levels of the drug have found great discrepancies with self reports. Mastro says the researchers have stored blood samples from participants and plan to assess drug levels.
Two other large studies of PrEP in women are under way in sub-Saharan Africa and will continue. Mitchell Warren, head of the AIDS Vaccine Advocacy Coalition in New York City, urges people not to extrapolate from the FEM-PrEP results. "It must be seen for what it is: the closure of a single trial in a field that has generated exciting results in the past," he says.