Early Treatment With Three Classes of Antiretrovirals Quickly Reduces Viral Loads, Study Says
Early treatment with a combination therapy that contains three classes of antiretroviral drugs can reduce viral loads quickly -- raising the possibility that HIV can be eliminated in people with already low viral loads following aggressive treatment with new drug classes -- according to study published in the June 15 issue of the Journal of Infectious Disease, Bloomberg reports.
Anthony Fauci, director of NIH's National Institute of Allergy and Infectious Diseases, and colleagues followed seven HIV-positive people for 3.5 to 4.5 years, measuring the number of resting CD4+ T cells in which HIV remained throughout treatment. The study found that early treatment with the three-drug combination therapy reduced the number of infected resting T cells by 50% every 4.6 months. Based on the results, the researchers estimated that 7.7 years of the combination therapy could all but eliminate HIV among people who began treatment early.
Although the number of study participants who started the combination therapy early, remained on treatment for years and had low viral loads might be small, studying them "will be of considerable value in assessing the feasibility of eradication of HIV," the researchers said. According to Fauci, the next step is to see if the aggressive treatment, along with Roche's Fuzeon and Merck's Isentress, can eradicate the virus. "The first step is to see how far we can push the envelope" in terms of reducing viral loads, Fauci said, adding, "We now have a scientific basis to feel that it's at least worth pursuing it in some select patients."
Fuzeon and Isentress attack parts of HIV that are not affected by other classes of antiretrovirals, Bloomberg reports. Such drugs have the best chance of eradicating HIV because the virus likely has not mutated to develop defenses against the new medications, Fauci said. He added that the proposed study also might help physicians decide when and how to use currently available antiretrovirals. If doctors could get HIV-positive people completely off their treatment regimens, it might be worth the risk of the aggressive treatment, Fauci said. Participants already are lined up for the proposed study, according to Bloomberg. If participants' viral loads decrease to undetectable levels, researchers will stop treatment, according to Fauci. He added that participants will be monitored so they can start therapy if the virus reappears.
In a related editorial, David Margolis and Nancie Archin of the University of North Carolina-Chapel Hill write that a risk of aggressive treatment is that measurements of viral loads are not always accurate. "The few infected cells remaining might be enough to reignite infection," the authors write, adding, "And, of course, the possibility exists that HIV may rarely persist in cells other than resting T cells" (Lauerman, Bloomberg, 5/15).
The study is available online.