Recent Developments in Targeting Eosinophil Accumulation as a Novel Therapeutic Approach for Asthma

Current therapies for asthma are aimed at controlling disease symptoms and for the majority of patients inhaled glucocorticoid anti-inflammatory therapy is both effective and well-tolerated. However, concerns remain about the ad- verse effects of glucocorticoids while a subset of asthmatic patients remains symptomatic despite optimal treatment thereby creating a clear unmet medical need. There is considerable evidence that implicates eosinophils as important ef- fector cells and immunomodulators in the inflammation characteristic of asthma. Numerous in vitro and animal studies have demonstrated essential roles for cell adhesion molecules in eosinophil adhesion and transendothelial migration in- cluding the selectins, ICAM-1, VCAM-1 together with many of the  1 and  2 integrins. A large body of evidence has also implicated several cytokines and chemokines in the selective recruitment of eosinophils to sites of asthmatic inflam- mation. Biopharmaceutical approaches have been used to identify inhibitory molecules that target key elements in the processes controlling eosinophil accumulation in asthma. This review will summarise the problems and successes regard- ing recent developments in therapeutic strategies aimed at reducing eosinophil-mediated inflammation in the asthmatic lung.