Inhaled corticosteroids are likely to be only effective in asthma patient with eosinophilic inflammation. Similarly, biotherapeutic agents currently available have been efficacious only in relevant phenotypes.
Future therapeutic targets for type 2 cytokine–driven asthma are airway-derived cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), epigenetically programmed to remain constitutively expressed.
Targeting these epigenetically programmed epithelial-derived mediators may be more likely to improve day-to-day asthma symptoms, in contrast to targeting mediators of the adaptive immune system, which primarily ameliorates asthma exacerbations.
The immunology of asthma. Larry Borish. Annals of Allergy, Asthma and Immunology, August 2016, Volume 117, Issue 2, Pages 108-114 (free full text).
The World Allergy Organization (WAO) Small Airways Working Group publishes a monthly "What's New?" summary and I have served as its editor since 2011. The summary features the top 3 asthma/small airways articles each month. The article above is a part of the project. The archive is here: http://www.worldallergy.org/small_airways_group/reviews/archive.php
Image source: Image source: FDA and Wikipedia, public domain.