OBJECTIVES: Omalizumab is an innovative treatment for difficult-to-treat allergic asthma. The mechanism of action of this type of treatment relies on impeding the binding of IgEs to their cellular receptor, thus blocking the inflammatory cascade. Objective of this study is to assess real-world clinical and economical outcomes associated to add-on omalizumab in difficult-to-treat allergic asthmatics. METHODS: In the present study, we report on the clinical and economical outcomes associated with omalizumab use in a cohort (n=23) of Italian adult asthmatics treated for a mean of 10 months (range: 2-22). The pharmacoeconomic value of the treatment is assessed with the cost/utility ratio evaluation. RESULTS: Omalizumab significantly improved asthma control and these patients’ health-related quality of life, with respect to the year preceding its inclusion in their therapeutic strategy. Despite reducing the costs of symptomatic drugs and hospital care for this patient population, the net economic effect of omalizumab introduction is an estimated increase of about €350 in overall monthly costs. However, when related to the increase in health benefits, this cost increase results in an incremental cost/utility ratio of about €26,000/quality-adjusted life years gained, a favourable value according to the willingness to pay for health benefits in industrialised countries. CONCLUSIONS: Omalizumab therapy significantly improved clinical outcomes in difficult-to-treat asthmatic patients. Costs also increased, but this increase appears to be justified by the important clinical benefits achieved.