SAN FRANCISCO, CA—In a controlled trial of treatment-naïve Black patients with HIV infection, the single-tablet regimen of elvitegravir/cobicistat/emtricitabine/tenofovir DF (STB) was well-tolerated and safe compared with efavirenz/emtricitabine/tenofovir DF (ATR), according to results presented by David Hardy, MD from Cedars-Sinai Medical Center, Los Angeles, CA during IDWeek 2013.
Previously, a randomized controlled trial (Study 102) showed STB to demonstrate non-inferior efficacy to ATR at Week 48 and Week 96. However, a meta-analysis of HIV clinical trials has found that the efficacy of antiretroviral therapy is lower in Blacks compared with other subjects. For this reason, Dr. Hardy and colleagues conducted a subanalysis of Study 102 to examine the efficacy and safety of STB vs. ATR through Week 96 in Black vs. non-Black subjects. In Study 102, Blacks comprised 30% (106/348) of patients in the STB group and 26% (91/352) of patients in the ATR group.
At Week 96, the virologic success in Blacks for STB vs. ATR was 81% vs. 73% (difference, 8.6%; 95% CI, -3.4–20.6%) and, in non-Blacks, 86% vs. 85% (difference, 0.9%; 95% CI, -5.4–7.2%). Rates of treatment-emergent adverse events leading to study drug discontinuation in Blacks were 1% vs. 10% (P=0.006), and in non-Blacks, 7% vs. 6% (P=0.71), in the STB and ATR group, respectively.
Median changes in serum creatinine at Week 96 for Blacks on STB compared to ATR were 0.14mg/dL vs. 0.01mg/dL (P<0.001) and 0.13mg/dL vs. 0.01mg/dL (P<0.001) for non-Blacks. Median changes in serum creatinine at Week 96 within the same treatment arm by race were similar for both groups.
At Week 96, Blacks on STB compared to ATR had smaller median increases from baseline in total cholesterol (8mg/dL vs. 23mg/dL, P=0.004) and HDL (7mg/dL vs. 9mg/dL, P=0.097) and similar increases in LDL (8mg/dL vs. 13mg/dL, P=0.060) and triglycerides (1mg/dL vs. 5mg/dL, P=0.34). Increases in lipid parameters within the same treatment arm by race were similar for both groups.
“Blacks on STB vs. ATR through Week 96 had numerically higher rates of virologic success and high and similar increases in CD4 cell count,” Dr. Hardy noted. Low and similar rates of emergent drug resistance was also observed.