Cost-efficacy analysis of darunavir/r monotherapy in clinical practice.

Purpose of the study To evaluate the economic impact of a swiching strategy to DRV/r mx in clinical practice using Spanish prices. Methods Multicenter retrospective study of four tertiary hospitals in Spain. The analysis includes 147 patients switching to DRV/r mx mainly due to toxicity or simplification from March 2009 to June 2011. The Spanish costs (ex-factory price+VAT) per patient with HIV RNA<50 copies/ml were calculated, accounting for additional/ switch antiretroviral taken after initial treatment failure and management of adverse events. Cost of adverse events were based on a Spanish publication [] (updated by the inflation rate until april 2012) The horizon of the analysis was of 48 weeks. Summary of results Baseline characteristics were: women (30.6%), median age (49 yr), IDU (45%), AIDS stage (32%), HCV coinfected (48%, 40% with advanced fibrosis), length of HIV-RNA<1.7 before DRV/rtv mtx 67.6. Most frequent reasons for switching to DRVr mx were toxicity (62.6%) and simplification (23.8%). If a hospital with 600 patients in ART treatment, switched from 10% to 20% of its patients to DRV/r mx, there is a potential to save up to 448,000€/year. Conclusions Switching to DRV/r mx is a cost-effective strategy that allows more patients to be treated for a fixed budget. Higher cost saving is expected when toxicity is the reason for switching. [ABSTRACT FROM AUTHOR]