Darunavir/cobicistat maintains the effectiveness of darunavir/ritonavir in HIV-infected patients under mono or dual therapy.

Objectives: Darunavir/ritonavir (DRV/r) in mono or dual therapy has proven efficacy in selected patients. The aim of this study was to evaluate the efficacy of switching from DRV/r to DRV/cobicistat (DRV/c) in patients under mono or dual therapy.

Methods: This was a prospective multicenter cohort study of patients using DRV/r under mono or dual therapy plus lamivudine who changed to DRV/c maintaining the previous regimen. All patients had a controlled HIV viral load (<50 copies/ml) when switched and were examined every 12 weeks. The primary end-point was the percentage of participants without virological failure (VF) at week 48 in the intent-to-treat analysis. The CD4 cell count and concentrations of cholesterol, triglyceride, and creatinine were measured from baseline to week 48.

Results: A total of 162 patients were included: 68.5% were men, and their mean age was 46 ± 12 years. Seventy (43.2%) patients were treated with DRV/r monotherapy, and 92 (56.8%) were treated with DRV/r plus lamivudine. The efficacy at week 48 was 95.1% (95% CI: 90.6%-97.5%) in the intent-to-treat analysis and 98.7% (95.5-99.6%) in the on-treatment analysis. Two VFs were documented but without development of resistance mutations. No significant changes were found in the lipid profile. Creatinine concentration increased significantly by 0.07 mg/dl (0.04-0.10, P < 0.001).

Conclusions: Switching from DRV/r to DRV/c in patients under mono or dual therapy is safe and effective.