Tailored therapy for severe asthma.

Patients with severe asthma or COPD have often a suboptimal symptom control due to inadequate treatment. A better understanding of pathogenetic mechanisms, phenotypes, endotypes and the new technologies available in the fields of molecular biology and immunogenetics have made it possible to synthesize specific monoclonal antibodies virtually able to interact with any target antigen, or to open a way for new therapeutic target options. At the moment, the only biologic drug available in clinical practice is omalizumab. To overcome the limits of omalizumab, the research has focused on new monoclonal antibodies presenting higher avidity for IgE (e.g. ligelizumab and lumiximab) and ability to interact also with low affinity IgE receptor (FcϵRII). At present, many new biological drugs with different mechanisms of action and targets are matter of research. It is very important to identify the asthmatic phenotype in order to select the most appropriate drug for the individual patient. The most promising agents are targeted against cytokines of Th2 pattern and related receptors, such as IL-2 (daclizumab) and IL-13 (lebrikizumab) or IL-5 in patients with hypereosinophilia (mepolizumab, reslizumab and benralizumab). Other interesting drugs have as a target TNF-α or its soluble receptor (infliximab, golimumab and etanercept) or IL-1 (canakinumab), a cytokine with an important systemic proinflammatory action. Finally, the discovery of increased levels of C5a in the airways of asthmatic patients has led to the synthesis of a specific monoclonal antibody (eculizumab). Further help should come from the identification of biomarkers that can guide in choosing the best treatment for the individual patient, such as IgE for omalizumab or periostin for lebrikizumab.