Hemispherx Publishes New Data on Ampligen®'s Activity in Chronic Fatigue Syndrome (CFS)

Hemispherx Publishes New Data on Ampligen®'s Activity in Chronic Fatigue Syndrome (CFS)

....Improves EKG parameter associated with Sudden-Onset Severe Cardiac Conditions

Philadelphia, PA, Monday, November 22, 2010: Hemispherx Biopharma, Inc. (NYSE Amex: HEB) (the "Company"), announced the publication of a peer-reviewed article providing new data on Ampligen® [rintatolimod; poly(I)•poly(C12,U)], an experimental therapeutic in Phase III clinical testing, in the current issue of The Journal of Applied Research. The report is entitled "Cardiac Toxicity in Chronic Fatigue Syndrome (CFS): Results from a Randomized 40-Week Multicenter Double-Blind Placebo Control Trial of Rintatolimod". Findings include discussion of the sedentary lifestyle produced by extreme fatigue which is a significant risk factor for heart disease, a leading cause of death in patients with CFS. Thus, cardiac abnormalities, including abnormal electrocardiograms (EKGs), are common in CFS patients despite their relatively young age.

The AMP-516, Phase III FDA-authorized study in CFS evaluated the therapeutic effectiveness of Ampligen®, an experimental therapeutic, and included repeated measurements of the QT interval, a component of EKG testing. Prolongation of the EKG QT interval is a known risk factor in sudden cardiac death (Long QT Syndrome) due to the induction of fatal cardiac arrhythmias. A greater portion of the placebo patients were found to have a significant prolongation of the QT interval compared to patients who had received Ampligen® twice weekly. The prolonged QT interval in the placebo group was associated with continued use of certain concomitant medications, which are known to prolong the QT interval and used by CFS patients in an attempt to mitigate symptoms of the disease. In contrast, patients randomized to receive Ampligen were able to significantly reduce their dependency on these same medications.

Concomitant medications which increase the QT interval may carry a "black box" warning on their labels since prolonged QT intervals are associated with cardiac arrhythmias which may result in sudden death.

The AMP-516 study was one of the studies submitted to FDA in the Ampligen® NDA, which resulted in the previously-announced November 25, 2009 Complete Response Letter, in which FDA requested that additional data be generated and submitted on effectiveness measures and potential QT interval effects.

About Hemispherx Biopharma
Hemispherx Biopharma, Inc. is an advanced specialty pharmaceutical company engaged in the clinical development of new drug entities for treatment of seriously debilitating disorders. Hemispherx' flagship products include Alferon N Injection® (FDA approved for a category of sexually transmitted diseases) and the experimental therapeutics Ampligen® and Alferon® LDO. Ampligen® represents experimental nucleic acids being developed for globally important debilitating diseases and disorders of the immune system. Hemispherx' platform technology includes agents for potential treatment of various severely debilitating and life threatening diseases. Hemispherx has an extensive number of patents comprising its core intellectual property estate and a fully commercialized product (Alferon N Injection®). The Company wholly owns and exclusively operates a GMP certified manufacturing facility in the United States. For more information please visit www.hemispherx.net.

Hemispherx Biopharma, Inc.,
Dianne Will, Investor Relations
(518) 398-6222, Fax: (518) 398-6369

HEB's Web Site: www.hemispherx.net

Information contained in this news release, other than historical information, should be considered forward-looking and is subject to various risk factors and uncertainties. For instance, the strategies and operations of Hemispherx involve risk of competition, changing market conditions, change in laws and regulations affecting these industries and numerous other factors discussed in this release and in the Company's filings with the Securities and Exchange Commission. Any specifically referenced investigational drugs and associated technologies of the Company (including Ampligen® and Alferon® LDO) are experimental in nature and as such are not designated safe and effective by a regulatory authority for general use and are legally available only through clinical trials with the referenced disorders. The forward-looking statements represent the Company's judgment as of the date of this release. The Company disclaims, however, any intent or obligation to update these forward-looking statements. The planning, completion, results or submission of clinical trials do not imply that any study product will ever be approved commercially for the studied or other treatment indications.