Squires KE, et al. – In this study, authors classified the 144–week results of the open–label, multicenter Atazanavir/Ritonavir Induction with Epzicom Study (ARIES) by gender to compare treatment responses. Over 144 weeks, there appeared no significant gender differences in efficacy, safety, or fasting lipid changes with abacavir/lamivudine + atazanavir or abacavir/lamivudine + atazanavir/ritonavir (ATV/r).

Methods

• 369 HIV–infected, antiretroviral–naïve subjects receiving once–daily abacavir/lamivudine + atazanavir/ritonavir (ATV/r) whose HIV–1 RNA was <50 copies/mL by week 30 were included.
• These subjects were randomized 1:1 at week 36 to maintain or discontinue ritonavir for 108 subsequent weeks.
• Analysis of between– and within–treatment gender–related efficacy and safety differences was performed.

Results

• Subjects included 85% male; 64% were white; mean age was 39 years, baseline median HIV–1 RNA was 114,815 copies/mL, and median CD4+ cell count was 198 cells/mm³.
• The groups were similar in terms of gender (ATV [n=189]: 29 females/160 males; ATV/r [n=180]: 25 females/155 males) and most other demographics; more females than males were black (65% vs 25%) and fewer females had baseline HIV–1 RNA ≥ 100,000 copies/mL (41% vs 58%).
• At week 144, there appeared no marked differences between genders in proportion maintaining HIV–1 RNA <50 copies/mL (ATV, 79% vs 77%; ATV/r, 60% vs 75%) or <400 copies/mL (ATV, 83% vs 84%; ATV/r, 68% vs 82%) (intent–to–treat–exposed: time to loss of virologic response analysis); median CD4+ change from baseline (ATV, +365 vs +300 cells/mm³; ATV/r, +344 vs +301 cells/mm³); proportion with treatment–related grade 2–4 adverse events (baseline to week 144: ATV, 41% vs 31%; ATV/r, 36% vs 43%; weeks 36 to 144: ATV, 14% vs 13%; ATV/r, 24% vs 23%); or proportion developing fasting lipid changes.
• Similar female and male virologic failure rates (ATV, 0 vs 5; ATV/r, 2 vs 4) and proportions completing the study were observed during the extension phase.
• In this study, primary withdrawal reasons were loss to follow–up and pregnancy for females and loss to follow–up and other for males.