HIV TREATMENT TRIAL FINDS NRTI-FREE REGIMEN SAFE

In the first head-to-head comparison between two commonly used HIV treatments, researchers found one triple-drug therapy was significantly more effective at reducing HIV viral load in the blood when used as a first-line treatment. Results of the clinical trial, which sought to determine from among three different therapies the optimal approach for patients beginning HIV treatment for the first time, are to be reported at the International AIDS Conference.

Of the two triple-drug approaches evaluated in the randomized trial, the therapy consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) with efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI), suppressed the virus to undetectable levels in more participants than the three-drug combination of two NRTIs and a protease inhibitor called lopinavir/ritonavir. Moreover, a third regimen, efavirenz and lopinavir/ritonavir, performed nearly as well as the three-drug cocktail with efavirenz, suggesting initial therapy need not include NRTIs, a class of drugs that can produce intolerable side effects in some patients.

The NRTI-free combination of lopinavir/ritonavir and efavirenz had never before been studied as first-line therapy in a large randomized clinical trial, in part because of a general belief that combining an NNRTI with a protease inhibitor could result in resistance to two important classes of drugs. But earlier studies with other drug combinations suggested the approach would be safe.

The study included 753 participants at 55 centers and was conducted under the auspices of the AIDS Clinical Trials Group. Each participant was randomly assigned to one of the three treatment arms. Participants in the triple-drug therapy groups each received two NRTIs: lamivudine, plus their choice of stavudine, zidovudine or tenofovir disoproxil fumarate.