Glaxosmithkline plc has won FDA approval to market Nucala (mepolizumab) for use in children as young as 6 with severe eosinophilic asthma (EA). The therapy already had FDA approval as an add-on maintenance treatment for kids with the same condition ages 12 and older. Approval of the sBLA, submitted last November, catches the U.S. market up to the EU, where Nucala has been approved as an add-on treatment for children ages 6 to 17 since August 2018.