Truvada, a prescription drug used to prevent HIV infection, was recommended earlier this year by the CDC in combination with condoms for high-risk individuals. However, despite trials indicating that the drug is both safe and effective, many were worried that those using the drug would not take it as recommended and that taking the drug would increase risky behavior. However, a new study conducted by researchers at the University of California, San Franciscoas an extension of the original study which found that this drug is effective, reports that these worries are unfounded.
The original study reported that taking Truvada daily reduced the risk of HIV by 42 percent among men and transgendered women who have sex with men. The current study followed about 1600 HIV-negative individuals at high risk for HIV, randomized to take either a daily placebo pill or truvada. Participants were followed for 72 weeks. Researchers reported that there were no new cases of HIV in those study participants who took truvada four or more times each week, although this level of adherence was only seen 33 percent of the time, as measured by presence of the drug in blood samples. However, a reduction in risk of HIV was seen even in those who did not take the pill as regularly. In those individuals with no drug in the blood, HIV incidence was 4.7 cases per 100 person-years. That number was 2.2 cases per 100 person-years in those taking less than two tablets per week and dropped to 0.6 cases in those taking two to three pills a week. Researchers also reported that there was no increase in sexually dangerous behavior as a result of taking the pill.
Dr. Stephano Vella of the Instituto Superiore di Sanita in Rome and former president of the International AIDS society comments, The study is real-life proof that PrEP can work. It s especially important that the study answers the question of whether adherence to the medication has to be 100% These are very, very important data.
However, ACSH s Dr. Josh Bloom adds, The fact that the study found that adherence was only good 33 percent of the time really enforces the idea that combination therapy is going to be the most effective therapy in preventing HIV. As I ve said before, Truvada is a great drug, but it can only do so much. Although the results of this study do show that Truvada will have some effect even when not taken regularly, the biggest public health benefit is going to be seen when this drug is used in combination with condoms as the CDC recommends.