What is asthma?

Asthma is a common, chronic airways disease affecting all age groups with large variations in prevalence between geographies. Asthma is increasingly recognised as a heterogeneous disease consisting of a variety of clinical and inflammatory phenotypes with an inconsistent response to treatment. Many asthma patients may achieve acceptable asthma control on lower dose of asthma medication. However, a minor group of patients with severe asthma remain a major challenge by a persistent requirement of high dose asthma therapy in attempt to be controlled. Patients with severe disease present the largest burden of disease due to frequent exacerbations, poor quality of life and increased health care costs. Recently, multiple targeted biological therapies have become increasingly available for subsets of patients with severe asthma. Nevertheless, severe asthma still represents an ongoing unmet need.