Simplification to dual therapy (atazanavir/ritonavir + lamivudine) versus standard triple therapy [atazanavir/ritonavir + two nucleos(t)ides] in virologically stable patients on antiretroviral therapy: 96 week results from an open-label, non-inferiority, randomized clinical trial (SALT study).

Abstract

Objectives: We evaluated whether maintenance therapy with tazanavir/ritonavir plus lamivudine (ATV/r+3TC) was non-inferior to ATV/r plus two nucleosides (ATV/r+2NUCs) at 96 weeks of follow-up. Methods: SALT is a multicentre, open-label, non-inferiority clinical trial in HIV-1-infected virologically suppressed patients. Hepatitis B virus surface antigen-negative subjects with no previous treatment failure/resistance mutations and HIV-1-RNA ,50 copies/mL for ≥6 months were randomized (1:1) to ATV/r+3TC or ATV/r+2NUCs. The primary endpoint was HIV-1-RNA ,50 copies/mL in the PP population. Non-inferiority was demonstrated if the lower bound of the 95% CI for the difference was not below 212%. Results: Some 286 patients were analysed. At week 96, 74.4% had HIV-1-RNA ,50 copies/mL in the ATV/r+3TC arm versus 73.9% in the ATV/r+2NUCs arm (95% CI for the difference, 29.9%–11.0%). In both groups, similar values were observed for patients with confirmed virological failure in ATV/r+3TC versus ATV/r+2NUCs (9 versus 5), death (1 versus 0), discontinuation due to ART-related toxicity (7 versus 11), withdrawal from the study (7 versus 9) and loss to follow-up (6 versus 6). One patient taking ATV/r+2NUCs developed resistance mutations (M184V and L63P). Similar values were obtained for change in mean CD4 count [19 versus 18 cells/mm3 (95% CI for the difference, 249.3–50.7), grade 3–4 adverse events (70.7% versus 70.2%) and changes in the global deficit score, 20.3 (95% CI, 20.5 to 20.1) for ATV/r+3TC, versus 20.2 (95% CI, 20.4 to 20.1) for ATV/r+2NUCs]. Conclusions: The long-term results of switching to ATV/r+3TC show that this strategy is effective, safe and noninferior to ATV+2NUCs in virologically suppressed HIV-infected patients.