OBJECTIVES: The objective is to describe the healthcare resource utilization and cost patterns associated with severe uncontrolled allergic asthma, based on data from Dutch patients collected in the EXPERIENCE study. METHODS: EXPERIENCE was a prospective, open-label, observational, multicenter, multicountry study in patients with severe persistent allergic asthma treated with omalizumab. The Global Evaluation of Treatment Effectiveness (GETE) was used to evaluate patient response. Healthcare resource use and number of exacerbations were captured for one year prior to the start of the study for all patients and continued for 104 weeks until end of the study. Hospitalizations, specialist visits and medications were included in this analysis for year before study and first year of study. Unit cost prices taken from 2010. RESULTS: A total of 154 subjects were included in ITT population. There were 2.5 clinically significant (CS) exacerbations/patient year prior compared to 0.90 CS exacerbations/patient for year of study on omalizumab. The total number of CS severe (CSS) exacerbation was 0.95 CCS exacerbations/patient for year prior and 0.26 CSS exacerbations/patient for year of study. The results indicate that patients in this study have an average cost of €4257/patient in the year prior to the study and €2583/patient cost during the study year, excluding omalizumab costs. The biggest cost drivers are hospitalization, work days lost and other asthma medications. The total omalizumab costs were €12,652/patient plus €1,171/patient for administration cost. CONCLUSIONS: This study reflects real life clinical practice and associated costs for omalizumab treatment of severe allergic asthma patients. It indicates a reduction in CS and CSS exacerbation rates of 64% and 73%, respectively associated with a 40% reduction in treatment costs when using omalizumab. Keeping in mind the study limitations associated with the observational setting, it provides estimated costs for patients with severe uncontrolled allergic asthma based on ‘real-world’ Dutch practice patterns.