A Cost-Effectiveness Comparison of Alosetron, Eluxadoline, and Rifaximin in the Treatment of Irritable Bowel Syndrome with Diarrhea

Abstract

1.1. Objective: The recurrent and complex Irritable Bowel Syndrome (IBS) has major impact on healthcare cost and quality-of-life (QoL) with highest prevalence and lowest QoL score of diarrhea predominant IBS (IBS-D). However, to treat IBS-D, Alosetron, Eluxadoline and Rifaximin are the only FDA-approved medications. There is a lack of standardized guidelines to recommend optimal therapy. Therefore, the aim of the study was to develop a decision-making analytical model to evaluate the economic and humanistic implications of the three approved medications in individuals with IBS-D. 1.2. Method: This study included estimates from clinical trials which measured IBS quality of life (IBS-QoL) for each treatment compared to placebo. The costs for individual treatment arm were the average wholesale prices from Red Book. A 12-week cost-effective decision-making analytical model was developed. The costs for the associated adverse events were weighted by the respective probabilities to evaluate the cost per quality-adjusted life year (QALY) gain and incremental cost-effectiveness ratio (ICER) as the study outcomes. 1.3. Results: The management cost for unit increment of QALY with respect to placebo was the least for Rifaximin treatment ($21,457); and the highest for alosetron treatment ($138,111). The ICER values of base case indicated dominance of Rifaximin over Eluxadoline by $291,123; and of Eluxadoline over alosetron by $482,767. In a willingness-to-pay range of $50,000 to $100,000, Rifaximin is the preferred option for 80% of IBS-D patients. 1.4. Conclusion: The results indicate that Rifaximin was the most cost-effective treatment among all the three regimens to manage IBS-D symptoms based on the parameters considered in this study.