Background : Omalizumab is a humanized monoclonal antibody which selectively binds to IgE and is employed to manage moderates to severe allergic asthma. It decreases severity of asthma episodes and enhances global asthma management particularly in patients who are non compliant with other treatments. Objectives: In this study, the effectiveness of safety as well as the clinical result of the Omalizumab in patient diagnosed with moderate to severe allergic asthma will be assessed. Study design : A Systematic Review