Hemispherx Presents Potential Avian Influenza Treatment Breakthrough at Paris Conference.

Alferon-LDO Primate Results Suggest Potential to Treat Healthcare Workers and "First Responders" in HPAI Outbreak

PARIS -- Hemispherx Biopharma, Inc. (AMEX: HEB), a biopharmaceutical company engaged in the clinical development and manufacture of new drug entities for pandemic disease threats, announced today a new scientific report featuring its antiviral therapeutic product candidate Alferon-LDO in combating highly pathogenic avian influenza (HPAI), also known as "bird flu." Alferon-LDO is a low-dose experimental oral formulation of the Company's Alferon-N([TM]) product, which is already approved by the United States FDA for the treatment of refractory genital warts (HPV).

The report concludes that Alferon-LDO appears to have potential as a preventive agent and/or treatment against avian influenza, reducing the severity of pathology resulting from infection of established animal model non-human primates (macaques) by a highly pathogenic strain of avian flu.

As noted in a 2006 Oxford University Clinical Research Unit study titled "Fatal outcome of human influenza A (H5N1) is associated with high viral load and hypercytokinemia," illness caused by the avian influenza A virus stems most directly from the body's own response to infection, an overwhelming reaction sometimes termed a "cytokine storm." In the words of the Oxford University study, "high viral load, and the resulting intense inflammatory responses, are central to influenza H5N1 pathogenesis. The focus of clinical management should be on preventing this intense cytokine response, by early diagnosis and effective antiviral treatment."

To study the effects of Alferon-LDO, researchers administered macaque subjects with the drug via the animals' gum tissues, in a range of

three dosing concentrations, with a fourth untreated group serving as a control. Following exposure of the dosed and untreated test subjects to the highly pathogenic HPAI strain A/Vietnam/1194/04, throat and nasal swabs were taken, gross pathology and viral loads were evaluated and representative samples of lung tissues were analyzed for pathologic changes.

Examination of the lungs revealed evidence of a dose-related reduction of infection-related pneumonia. Two of the three animals in the highest dosing group showed no evidence of lung infection to the naked eye, while lower-dose groups did show visible infection. This dose-related response was noteworthy given that viral loads were consistent among the subjects receiving the various dosages and the control group. Ten days of ongoing Alferon-LDO prophylaxis and treatment reduced the severity of pneumonia despite the continuing presence of the influenza virus.

The study results are being presented at the ongoing 2nd International Conference on Avian Influenza, being held at the Pasteur Institute.

Recent medical reports from critical influenza regions such as Southeast Asia indicate that presently available therapies, even given at the highest doses available via intravenous routes, do not alter the avian influenza death rate, which at present is greater than 60%. Given the danger of an avian flu pandemic, the lack of an effective available therapy and the fact that Alferon-N[TM] is already approved by the United States FDA as safe and effective in treating a different virus, Hemispherx management is hopeful that Alferon-LDO can receive expedited review and emergency-based approval as an anti-HPAI agent, solely relying on the "animal rule" for demonstration of efficacy.

"The threat of global pandemic illness from infectious disease puts the highest possible priority on finding therapeutic strategies that can protect first responders and save patient lives," commented Dr. William Carter, Chairman and Chief Executive Officer of Hemispherx. "We are encouraged by the strong potential that Alferon-LDO, an experimental formulation of our previously licensed drug, shows as a prophylactic agent, especially for front-line health care workers, and its additional potential to effectively treat avian flu in those already infected."

About Hemispherx Biopharma

Hemispherx Biopharma, Inc. is a biopharmaceutical company engaged in the manufacture and clinical development of new drug entities for treatment of seriously debilitating disorders. Hemispherx's flagship products include Alferon N Injection[R] and the experimental therapeutics Ampligen[R] and Oragens[R]. Alferon N Injection[R] is approved for a category of STD infection, and Ampligen[R] and Oragens[R] represent experimental RNA nucleic acids being developed for globally important viral diseases and disorders of the immune system. Hemispherx's platform technology includes large and small agent components for potential treatment of various severely debilitating and life threatening diseases. Hemispherx has in excess of 100 patents comprising its core intellectual property estate, a fully commercialized product (Alferon N Injection[R]) and GMP certified manufacturing facilities for its novel pharma products. For more information please visit 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[R], Alferon LDO and Oragens) 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. Clinical trials for other potential indications of the approved biologic Alferon N Injection[R] do not imply that the product will ever be specifically approved commercially for these other treatment indications.