* Omalizumab (Xolair) is the 149 kDa, glycosylated antibody which is produced by an engineered CHO cell line. This recombinant humanized monoclonal antibody blocks the high-affinity Fc receptor of immunoglobulin E (IgE). It is used to treat patients with moderate-persistent to severe-persistent asthma.The product was approved in the EU in 2005, although it has been available in the US since 2