Recent developments in the use of biologics targeting IL-5, IL-4, or IL-13 in severe refractory asthma.

Severe or refractory asthma is seen in approximately 5% of asthmatic subjects who have unsatisfactory symptom control despite adherence to high-dose inhaled glucocorticoid therapies resulting in significant morbidity, reduced quality of life and health-care cost implications. Asthma exhibits marked heterogeneity both clinically and at the molecular phenotypic level requiring specifically targeted treatments to block the key pathways of the disease. Monoclonal antibody-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5, and IL-13 have considerable potential as effective treatments for severe asthma. Areas covered: This review is based on recent English-language original articles in PubMed or Medline that reported significant clinical findings on the current status, therapeutic potential, and safety of biologics targeted at IL-4, IL-5, and IL-13 in the treatment of asthma together with the potential utility of simple reproducible non-invasive biomarkers to guide the effective use of biologic-based therapy that do not require direct sampling of the airways Expert commentary: The further development of reproducible and straightforward discriminatory non-invasive biomarkers may aid identification of those patients most likely to benefit from treatment with these interventions.