The Food and Drug Administration late Monday broadened the use of an already available anthrax drug from Emergent Biosolutions Inc. EBS, -0.57% to a larger treatment population. The agency approved Emergent's BioThrax for use in people 18 to 65 years old who have had suspected or confirmed exposure to anthrax. Previously, the indication for the drug was for people who were at a high risk of exposure to the bacteria. Emergent Biosolutions shares rose 1% to $38.10 after hours.