PHILADELPHIA, Dec. 14, 2010 (GLOBE NEWSWIRE) -- Hemispherx Biopharma, Inc. (NYSE Amex:HEB) (the “Company” or “Hemispherx”) announced today that the Food and Drug Administration (FDA) granted a 12 month extension for the Company to modify its NDA in response to a Complete Response Letter (CRL) received November 25, 2009 for the CFS indication. In the request received by the Agency on November 24, 2010, the Company cited new clinical laboratory data on the possible inter-relationships of XMRV positivity and responsiveness of CFS to its experimental drug, Ampligen®, a toll-like receptor 3 agonist. The request included a new formal protocol titled “Analysis of XMRV Markers from the Serum Samples of all Evaluable Subjects of the Clinical Study AMP-516,” which would extend the XMRV observations presented at the 1st International Workshop on XMRV held at the National Institutes of Health in Bethesda, MD, on September 7 and 8, 2010. In the request, Hemispherx pointed out that its ongoing analysis of XMRV in CFS would appear to be potentially most helpful in responding to certain aspects of the CRL as well as in pursuing the joint mission to offer potential novel treatments to CFS sufferers.