Long-term efficacy and safety of atazanavir/ritonavir treatment in a real-life cohort of treatment-experienced patients with HIV type 1 infection

Abstract

Atazanavir-based regimens have established efficacy and safety in both antiretroviral (ARV)-naive and -experienced patients. However, data evaluating effectiveness beyond 2 years is sparse. Therefore, we assessed the long-term outcomes of ritonavir-boosted atazanavir (ATV/r)-containing regimens in ARV-experienced patients in a clinical setting in a noncomparative, retrospective, observational study collecting data from three European HIV databases on ARV-experienced adults with HIV-1 infection starting an ATV/r-based regimen. Data were extracted every 6 months (maximum follow-up 5 years). Primary outcome was the proportion of patients remaining on ATV/r by baseline HIV-1 RNA (<500 or ≥500 copies/ml). Secondary outcomes included time to virologic failure, reasons for discontinuation, and long-term safety profile. The duration of treatment and time to virologic failure were analyzed using the Kaplan-Meier method. Data were analyzed for 1,294 ARV-experienced patients (male 74%; mean ART exposure 5.7 years). After 3 years, 56% (95% CI: 52%, 60%) of patients with baseline HIV-1 RNA <500 copies/ml and 53% (95% CI: 49%, 58%) of those with HIV-1 RNA ≥500 copies/ml remained on ATV/r. After 3 years, 75% (95% CI: 69%, 80%) of patients with baseline HIV-1 RNA <50 copies/ml remained suppressed and 51% (95% CI: 47%, 55%) of those with baseline HIV-1 RNA ≥50 copies/ml achieved and maintained virologic suppression. Although adverse events (AEs) were the main known reason for discontinuation, no unexpected AEs were observed. In a real-life setting ATV/r-based regimens demonstrated sustained virologic suppression in ARV-experienced patients. After long-term therapy the majority of patients remained on treatment and no unexpected AEs were observed.

FIG. 1.

Patient disposition.

FIG. 2.

Kaplan–Meier survival function. (a) Time to discontinuation and (b) time to virologic failure. N is the number of patients at baseline. There were *32 patients who had a missing baseline HIV-1 RNA assessment using an assay precision of at least 500 copies/ml and ^†164 patients who had a missing baseline HIV-1 RNA assessment using an assay precision of at least 50 copies/ml; thus, the total number of patients at risk irrespective of baseline HIV-1 RNA status at each time point is greater than the corresponding sum of patients at risk with available baseline HIV-1 RNA assessments.

FIG. 3.

Mean CD4 counts over time. N is the number of patients at baseline. *Data are predicted mean CD4 counts (solid lines)±95% confidence intervals (CI; dotted lines) derived from a mixed models repeated measures analysis. ^†There were 32 patients who had a missing baseline HIV-1 RNA assessment using an assay precision of at least 500 copies/ml; thus, the total number of patients with available CD4 count measurements irrespective of baseline HIV-1 RNA status at each time point is greater than the corresponding sum of patients with available CD4 count measurements and baseline HIV-1 RNA assessments.