FRIDAY, June 29 (HealthDay News) -- For treatment-naive patients with HIV-1 infection, the once-daily tablet with HIV integrase strand transfer inhibitor elvitegravir (EVG), co-formulated with the CYP3A4 inhibitor cobicistat (COBI), emtricitabine (FTC), and tenofovir disoproxil fumarate (TDF), also known as EVG/COBI/FTC/TDF, is noninferior to a ritonavir-boosted (RTV) protease inhibitor regimen of atazanavir (ATV)/RTV+FTC/TDF, according to a phase 3 study published online June 29 in The Lancet.
Edwin DeJesus, M.D., from the Orlando Immunology Center in Florida, and colleagues conducted a noninferiority study to compare EVG/COBI/FTC/TDF with ATV/RTV+FTC/TDF as initial therapy for HIV-1 infection. Treatment-naive patients with HIV-1 RNA concentration of ≥5,000 copies/mL were randomly allocated to receive EVG/COBI/FTC/TDF (353 patients) or ATV/RTV+FTC/TDF (355 patients) plus matching placebos.
The researchers found that EVG/COBI/FTC/TDF was noninferior to ATV/RTV+FTC/TDF for the primary end point of an HIV RNA concentration of <50 copies/mL after 48 weeks (89.5 and 86.8 percent, respectively). Favorable safety and tolerability were seen for both regimens; 3.7 and 5.1 percent of patients, respectively, discontinued treatment due to adverse events. Abnormal liver function in fewer patients and smaller median increases in fasting triglyceride concentrations were seen in those receiving EVG/COBI/FTC/TDF. By week two, both groups experienced small median increases in serum creatinine concentration with accompanying decreases in estimated glomerular filtration rate, which generally stabilized by week eight.
"This study is the first fully powered, randomized, double-blind clinical trial to compare two single-tablet HIV treatments," the authors write. "If approved, EVG/COBI/FTC/TDF would be the only single-tablet, once-daily, integrase-inhibitor-based regimen available for initial HIV treatment."
Several authors disclosed financial ties to pharmaceutical companies, including Gilead Sciences, which funded the study and manufactures EVG/COBI/FTC/TDF.