Effectiveness and durability of darunavir/ritonavir (DRV/r) in DRV/r-experienced HIV-1-infected patients in routine clinical practice

INTRODUCTION: This was a descriptive non-interventional study in HIV-1-infected patients treated with DRV/r conducted in the clinical setting, with a single-arm prospective design. The primary objective was to collect data on utilization of darunavir/ritonavir (DRV/r) under the conditions described in the marketing authorization. Efficacy (measured as viral load [VL] <50 copies/mL and CD4+ cell count) was evaluated for DRV/r in combination with other antiretroviral (ARV) agents in routine clinical practice in Italy. MATERIALS AND METHODS: Here we describe an analysis of effectiveness and durability data from two cohorts of DRV/r-experienced patients with HIV-1 infection, already receiving DRV/r according to usual clinical practice, collected prospectively from June 2009 to December 2012: Cohort 1, data from patients from the DRV/r Early Access Program (TMC114-C226 study; N=235 patients) and Cohort 2, a separate cohort of ARV-DRV/r-experienced patients (N=407 patients), treated with DRV/r in the market. Patient characteristics are shown in Table 1. RESULTS: The median length of DRV/r exposure during the study was 925 days (interquartile range [IQR] 692–1006) in Cohort 1, and 581 (IQR 508–734) days in Cohort 2. Of those patients that completed the study, 94% and 87% of patients were virologically suppressed in Cohort 1 and 2, respectively, at last study visit (LSV). As expected, the virological suppression rate was higher in patients with baseline VL <50 copies/mL (Table 2). Mean CD4+ cell counts improved from baseline to LSV in both cohorts (Cohort 1: +54 cells/µL [95% CI 31, 77] and Cohort 2: +59 cells/µL [95% CI 44, 73]). High persistence rates were seen in both cohorts, with 75.3% of patients in Cohort 1 and 82.6% in Cohort 2 remaining on treatment at LSV; very few patients discontinued due to virologic failure (Table 1). Other reasons for study discontinuation are shown in Table 1. Very few patients changed DRV/r dosing during the study, 15 from 1200 to 800 mg o.d. CONCLUSIONS: In patients already treated with DRV/r, DRV/r-based ARV treatment provided effective viral suppression with long-lasting durability, low virological response failure, low discontinuation rates and good tolerability. These data confirm DRV/r to be an effective treatment choice in previously treated patients.