The Food and Drug Administration (FDA or Agency) is announcing the availability of a draft guidance for industry entitled “Acute Radiation Syndrome:  Developing Drugs for Prevention and Treatment.”  The purpose of this draft guidance is to provide information and recommendations to assist sponsors and other interested parties in the development of drugs to prevent or treat acute radiation syndrome (ARS) caused by exposure to ionizing radiation from accidental or deliberate events.  Generally, drugs developed for such indications will require approval under the regulations commonly referred to as the Animal Rule.