Lopinavir/ritonavir, atazanavir/ritonavir, and efavirenz in antiretroviral-naïve HIV-1-infected individuals over 144 weeks: an open-label randomized controlled trial.

Background: The objective of this study was to compare the efficacy of ritonavir boosted atazanavir versus ritonavir boosted lopinavir or efavirenz, all in combination with 2 nucleoside analogue reverse transcriptase inhibitors (NRTIs), over 144 weeks in antiretroviral-naïve HIV-1-infected individuals.

Methods: A prospective open-label randomized controlled trial was conducted at 29 sites in Sweden and Norway between April 2004 and December 2009. Patients were randomized to receive either efavirenz 600 mg once daily (EFV), or atazanavir 300 mg and ritonavir 100 mg once daily (AZV/r), or lopinavir 400 mg and ritonavir 100 mg twice daily (LPV/r). The primary endpoints were the proportion of patients with HIV-1 RNA < 50 copies/ml at 48 and 144 weeks.

Results: Of 245 patients enrolled, 243 were randomized and 239 received the allocated intervention: 77 EFV, 81 AZV/r, and 81 LPV/r. Median (interquartile range) CD4 cell counts at baseline were 150 (80-200), 170 (80-220), and 150 (90-216) per microlitre, respectively. At week 48 the proportion (95% confidence interval (CI)) of patients achieving HIV-1 RNA < 50 copies/ml was 86 (78-94)% in the EFV arm, 78 (69-87)% in the AZV/r arm and, 69 (59-78)% in the LPV/r arm in the intention-to-treat analysis. There was a significant difference between the EFV and LPV/r arm (p = 0.014). At week 144, the proportion (95% CI) of patients achieving HIV-1 RNA < 50 copies/ml was 61 (50-72)%, 58 (47-69)%, 51 (41-63)%, respectively (p = 0.8). Patients with CD4 cell counts of ≤ 200/μl or HIV-1 RNA > 100,000 copies/ml at baseline had similar response rates in all arms.

Conclusion: EFV was superior to LPV/r at week 48, but there were no significant differences between the 3 arms in the long-term (144 weeks) follow-up.