Cost-effectiveness analysis of raltegravir in treatment-experienced HIV type 1-infected patients in Spain

Raltegravir, a novel HIV-1 integrase inhibitor, has superior efficacy with optimized background treatment (OBT) vs. placebo+OBT in treatment-experienced HIV-1 patients. This study assessed the long-term cost effectiveness of raltegravir from a Spanish National Healthcare System perspective. A cohort-state-transition model was used to estimate clinical and economic outcomes associated with raltegravir+OBT vs. OBT alone. Subjects were stratified into health states according to HIV RNA level, CD4 count, and opportunistic infection (OI) history, and could transition into different health states over time based on projected long-term efficacy. Each health state was associated with a distinct treatment cost and utility (QoL) score. Model inputs for mortality, resource utilization, unit costs, OI risk, and long-term durability of viral suppression were obtained from clinical trials, published studies, and database analyses. Model outcomes were reported as incremental cost-effectiveness ratios (ICERs) in 2007 Euros per quality-adjusted life-year (€/QALY) gained. Costs and QALYs were discounted at 6% per year based on Spanish cost-effectiveness guidelines. Extensive sensitivity analyses were conducted. Five years of treatment with raltegravir+OBT resulted in an additional 4.5 years of undiscounted life expectancy vs. OBT alone. The ICER of raltegravir+OBT vs. OBT alone was €22,908/QALY and €31,431/QALY for 3- and 5-year use, respectively. Lower ICERs were observed with lower discount rates (3%) for costs and benefits, lower raltegravir price (20%), and shorter treatment duration (3 years). ICER was also sensitive to analytical time horizon and alternative sources of QoL scores. In treatment-experienced Spanish patients, raltegravir was projected to provide survival benefits and be cost effective.