Abstract : Asthma is a chronic inflammatory disease of the airways. The inflammatory process is driven by different pathways involving cytokines and other protein mediators. Patients with severe asthma are at high risk of severe exacerba¬tions and death and have few therapeutic options available. The¬refore, biological agents have been developed to help patients with refractory asthma by interfering with several compounds of the asthma inflammatory cascade. In addition to decreasing exacerbations, some of those treatments have a steroïd sparing role and many beneficial effects in asthmatics.