Economic Impact and Clinical Outcomes of Omalizumab Add-On Therapy for Patients with Severe Persistent Asthma: A Real-World Study

Background Omalizumab is a fully humanized monoclonal antibody indicated as add-on therapy to improve asthma control in patients with severe persistent allergic asthma. Aims The aim of this study was to evaluate social, healthcare expenditure and clinical outcomes changes after incorporating omalizumab into standard treatment in the control of severe asthma. Methods In this multicentre retrospective study, a total of 220 patients were included from 15 respiratory medicine departments in the regions of Andalusia and Extremadura (Spain). Effectiveness was calculated as a 3-point increase in the Asthma Control Test (ACT) and a reduction in the annual number of exacerbations. The economic evaluation included both direct and indirect costs. Incremental cost-effectiveness ratio (ICER) was calculated. Results from the year before and the year after incorporation of omalizumab were compared. Results After adding omalizumab, improvement of lung function, asthma and rhinitis according to patient perception, as well as the number of exacerbations and asthma control measured by the ACT score were observed. Globally, both healthcare resources and pharmacological costs decreased after omalizumab treatment, excluding omalizumab cost. When only direct costs were considered, the ICER was euro1712 (95% CI 1487-1995) per avoided exacerbation and euro3859 (95% CI 3327-4418) for every 3-point increase in the ACT score. When both direct and indirect costs were considered, the ICER was euro1607 (95% CI 1385-1885) for every avoided exacerbation and euro3555 (95% CI 3012-4125) for every 3-point increase. Conclusions Omalizumab was shown to be an effective add-on therapy for patients with persistent severe asthma and allowed reducing key drivers of asthma-related costs.