"Targeted therapy" - Anti-lnterleukin-5 zur Behandlung eosinophiler Erkrankungen

Recently, an anti-IL-5 antibody (mepolizumab) has been developed and used in a number of disorders characterized by elevated levels of eosinophils such as bronchial asthma, atopic eczema, hypereosinophilic syndrome, and eosinophilic gastrointestinal disorders. Since IL-5 represents the most important cytokine for eosinophil production, its inhibition leads to selective reduction of these cells and might therefore be a valuable therapeutic target in the aforementioned disorders. Mepolizumab is a fully humanized monoclonal antibody (IgGl, k) and blocks binding of human IL-5 to the α-chain of the IL-5 receptor complex on the eosinophil cell surface, leading to a reduced differentiation and proliferation of eosinophils in the bone marrow and to enhanced apoptosis in the tissue. Several studies with mepolizumab have been carried out to assess its efficacy in the treatment of asthma and atopic eczema and are currendy under way for hypereosinophilic syndrome and eosinophilic gastrointestinal disorders as well as for Churg-Strauss syndrome and nasal polyposis. Whereas mepolizumab did not lead to a significant clinical improvement of asthma and only to a weak amelioration of atopic eczema, preliminary investigations on the basis of the compassionate use of this compound showed excellent therapeutic effects in hypereosinophilic syndrome and eosinophilic gastrointestinal disorders. More detailed information is currently generated in multicenter, randomized, double-blind, placebo-controlled studies. Mepolizumab is a promising treatment option for several diseases characterized by elevated eosinophil numbers.