This is a double-blind, placebo controlled 4 week crossover study to investigate the efficacy and safety of AZD7624 (an inhaled p38 inhibitor) in corticosteroid resistant (CR) asthmatics. For the purpose of this study 10 symptomatic CR asthma patients with a FEV1% predicted <80% and normal bronchodilator response, 10 CS asthmatics and 10 healthy controls will be recruited.