Within the context of the heterogeneous phenotypic stratification of asthmatic 
population, many patients are characterized by moderate-to-severe eosinophilic 
asthma, not adequately controlled by relatively high dosages of inhaled and even 
oral corticosteroids. Therefore, these subjects can obtain significant 
therapeutic benefits by additional biologic treatments targeting interleukin-5 
(IL-5), given the key pathogenic role played by this cytokine in maturation, 
activation, proliferation, and survival of eosinophils. In particular, 
reslizumab is a humanized anti-IL-5 monoclonal antibody that has been found to 
be an effective and safe add-on therapy, capable of decreasing asthma 
exacerbations and significantly improving disease control and lung function in 
patients experiencing persistent allergic or nonallergic eosinophilic asthma, 
despite the regular use of moderate-to-high doses of inhaled corticosteroids. 
These important therapeutic effects of reslizumab, demonstrated by several 
controlled clinical trials, have led to the recent approval by US Food and Drug 
Administration of its use, together with other antiasthma medications, for the 
maintenance treatment of patients suffering from severe uncontrolled asthma.