Benralizumab: Targeting the IL-5 Receptor in Severe Eosinophilic Asthma Abstract. For patients with difficult-to-control, severe bronchial asthma, highly effective, targeted treatment options are available in addition to inhaled medication. In the presence of eosinophilia, inhibition of the interleukin-5 (IL5) axis with specific monoclonal antibodies promises to be an effective alternative to continuous systemic steroid therapy with few side effects. This review summarizes the data on benralizumab, a specific antibody against the IL-5 receptor alpha preventing receptor stimulation by IL-5 and activating a NK-cell mediated cytotoxic reaction with apoptosis of eosinophils. The s.c.-application of benralizumab leads within days to a virtually complete depletion of blood eosinophils with consecutive improvement in lung function and stabilization of asthma. For selected severe asthmatics, this is a promising therapy option.