WATERTOWN, Mass.--(BUSINESS WIRE)--Acusphere Inc. (OTCBB: ACUS) announced today that it has submitted an amendment to its New Drug Application (NDA) for ImagifyTM (Perflubutane Polymer Microspheres) for Injectable Suspension. Imagify is designed for the detection of coronary artery disease, the leading cause of death in the United States. The NDA was submitted to the U.S. Food & Drug Administration (FDA) in April 2008 and filed in June 2008. Imagify is designed to enable ultrasound to compete more effectively with nuclear stress testing, the leading procedure for detecting coronary artery disease. It is estimated that more than 10 million cardiac stress imaging procedures are done each year in the U.S. of which 6.5 million are conducted with exercise stress and 3.5 million are conducted with pharmacologic stress. If FDA accepts the submitted amendment, the Imagify indication will be limited to subsets of patients undergoing pharmacologic stress techniques. The amended indication is focused on patients where the risk-to-benefit ratio of Imagify is more compelling than the broader indication that was originally filed. Since this is a significant amendment to the NDA for Imagify, it is likely that the FDA will push back the Prescription Drug User Fee Act (PDUFA) target date for their complete response letter from February 28, 2009 to May 31, 2009.