Monoclonal antibody therapy for asthma

Asthma is characterized by airway inflammation and reversible airflow limitation. Severe asthma accounts for 5% to 10% of asthmatic patients but more than half of the cost of asthma care in the United States. There is increasing interest in characterizing and managing this difficult population. The mainstay of asthma treatment is the use of inhaled corticosteroids and bronchodilators, although in patients with severe asthma, many rely on systemic glucocorticoids for asthma control. Newer monoclonal antibodies are providing an alternative to systemic glucocorticoids for asthma control and exacerbation prevention. The first monoclonal antibody therapy approved for treatment of asthma was omalizumab, targeting IgE, a component of the allergic cascade. More recently, 2 monoclonal antibodies have been approved as add-on therapy for poorly controlled eosinophilic asthma. These target interleukin-5, a key cytokine in promoting eosinophil differentiation, survival, and recruitment. Another antibody targeting the interleukin-5 receptor on eosinophils is anticipating approval. Other monoclonal antibodies targeting a wide variety of intermediaries in the inflammatory cascade are under development. Evaluation of previously approved monoclonal antibodies that may have benefit in asthma is ongoing. An understanding of the pathophysiology of asthma and airway hyperreactivity, as well as use of biomarkers, will help clinicians appropriately target monoclonal antibody therapy to patients who are most likely to respond to these newer therapies.