Objectives: Severe asthma is a high-cost chronic disease with different inflammatory phenotypes, the eosinophilic phenotype being the most common. Benralizumab is a monoclonal antibody that targets this phenotype. This study evaluated cost-utility ratio of Benralizumab in patients with severe eosinophilic asthma in Costa Rica.

Method: A Markov-model was developed considering five-disease-stages: no exacerbation, exacerbations requiring oral corticosteroids (OCS), exacerbations requiring emergency department (ED) visit, exacerbations requiring hospitalization and death. A cohort of 100 patients was modelled from the social-perspective comparing Standard of Care (SoC) with Benralizumab and Omalizumab, respectively, in terms of avoided exacerbations requiring OCS, ED visits and/or hospitalizations with a time-horizon of 5 years. Costs and healthcare values were discounted by 3.5%, efficacy was based on the pivotal studies of these treatments. Base-case were 50-year-old-patients with uncontrolled severe eosinophilic asthma. Direct and indirect healthcare costs were considered. Willingness-to-Pay (WTP) threshold used was 3 times the gross domestic product per capita in Costa Rica (USD 36,231) at an exchange rate of CRC 628 per USD 1.

Results: Benralizumab avoided 1,240 exacerbations requiring OCS, 750 ED visits, 1,023 hospitalizations, 24,799 disability days and 25 deaths vs SoC. Omalizumab avoided 1,060 exacerbations requiring OCS, 736 ED visits, 938 hospitalizations, 23,010 disability days and 23 deaths vs SoC. Total discounted costs were: SoC$13,511,941; Benralizumab$15,959,828 and omalizumab$19,725,691. Benralizumab was a cost-effective strategy against SoC with an Incremental Cost Effectiveness Ratio (ICER) of $5,146 per Quality-Adjusted-Life-Year (QALY) gained, and cost-saving vs Omalizumab, resulting in less costs and better clinical outcomes. Based on the WTP of $36,231, Benralizumab has a 98% probability of being the best treatment option for severe eosinophilic asthmatic patients in Costa Rica.

Conclusions: Benralizumab is a cost-effective strategy for severe eosinophilic asthmatic patients in Costa Rica based on Costa Rican WTP threshold and it is a dominant strategy compared to Omalizumab.