GlaxoSmithKline plc announced that the U.S FDA has approved Nucala (mepolizumab) for use with other asthma medicines for the maintenance treatment of asthma in patients age 12 years and older who have a history of severe, breakthrough asthma attacks.  Nucala, a monoclonal antibody, is the first and only approved biologic therapy that targets interleukin-5 (IL-5), which plays an important role in regulating the function of eosinophils, an inflammatory cell known to be important in asthma.  Severe asthma is a debilitating condition in which patients are at high risk of frequent and serious asthma attacks.  Half of all severe asthma patients have at least one urgent care visit per year.