Biologics for severe asthma-Which, when and why?

Asthma is a common chronic inflammatory condition of the airways that affects about 350 million people globally. In 5%-10% of individuals, it is severe, with considerable morbidity and high health care utilization. The goal of asthma management is disease control by reducing symptoms and exacerbations and reducing corticosteroid-related morbidity. The era of biologics has revolutionized the management of severe asthma. Biologics have changed our expectations for severe asthma, especially in those people with type-2 mediated immunity. We can now explore the potential for changing disease trajectory and inducing remission. However, biologics are not a panacea for all severe asthma sufferers and despite their success there remains substantial unmet clinical need. We review the pathogenesis of asthma, phenotyping the heterogeneity of asthma, currently licensed and future biologic agents, how to choose the initial biologic, assessing the response, remission and switching of biologic therapies.