Approval is for hypereosinophilic syndrome, which occurs when there is a high number of a type of white blood cells   The U.S. Food and Drug Administration approved Nucala (mepolizumab) for adults and children aged 12 years and older with hypereosinophilic syndrome (HES) for six months or longer without another identifiable non-blood related cause of … Continue reading FDA Approves First Drug to Treat Group of Rare Blood Disorders in Nearly 14 Years