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.
References:
The immunology of asthma. Larry Borish. Annals of Allergy, Asthma and Immunology, August 2016, Volume 117, Issue 2, Pages 108-114 (free full text).
http://www.annallergy.org/article/S1081-1206(16)30180-6/fulltext
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.