Hemispherx Biopharma Enters Research Agreement with Defence R&D Canada.

PHILADELPHIA -- Efficacy Evaluation of Ampligen(R) and Alferon(R) for the Prophylaxis of Human Respiratory Influenza Virus Infection

Hemispherx Biopharma, Inc. (AMEX: HEB) announces that they have entered into an agreement with Defence R&D Canada - Suffield (DRDC), an agency of the Canadian Department of National Defence, to evaluate the antiviral efficacy of its experimental therapeutic Ampligen(R) and Alferon(R) for protection against human respiratory influenza virus infection in well validated animal models.

DRDC Suffield is conducting research and development of new drugs that could potentially become part of the arsenal of existing antiviral weapons to combat the bird flu. The initial study will focus on the testing of potential drugs against the respiratory influenza virus infection on a mouse-adapted strain of human influenza.

DRDC Suffield has already conducted extensive research in the use of liposome delivery technology to enhance the antiviral activity of a closely-allied Ampligen(R) analogue, Poly ICLC (an immunomodulating dsRNA) which is very similar to Ampligen(R). Results suggest that ribo nucleic acid-based drugs have the ability to elicit protective broad-spectrum antiviral immunity against various pathogenic viruses. Hence, there is the potential for efficacy to be maintained against mutating strains of an influenza virus. Liposomes, a carrier system for nucleic acid-based drugs, have shown an ability to protect these drugs against in vivo degradation, delivering them to intracellular sites of infection, thereby reducing any toxicity and prolonging their therapeutic effectiveness. Protection can be afforded for 21 days with two doses of dsRNA. It is believed that in humans with active flu infection, Tamiflu, given twice daily, may ameliorate symptoms.

"We are very pleased to be included in the DRDC Suffield Study" commented Dr. William Carter, Hemispherx CEO. "Previous studies have shown that there are certain limitations using poly ICLC as an antiviral drug due to its inherent toxicity even though it has pronounced therapeutic activity. In contrast, Ampligen(R) and Alferon(R) have encouraging safety profiles to date and Ampligen(R) shares similar structure with Poly IC. The experimental combination has the potential to be a very promising therapy."

In addition to the DRDC Suffield collaboration, Hemispherx is also engaged in broad-based ongoing experimental studies assessing the efficacy of their products Ampligen(R), Alferon N Injection(R) and Alferon LDO (Low Dose Oral)(TM) as an adjuvant or single agent antiviral with the National Institute of Infectious Diseases in Tokyo, the Princess Margaret Hospital in Hong Kong and various research affiliates of the National Institutes of Health in the United States.

Alferon N(R) is already commercially approved for another major viral infection, chronic refractory HPV, and Ampligen(R) has recently completed Phase III clinical testing in another viral associated disorder in the U.S.

About Defence R&D Canada

Defence R&D Canada (DRDC) is an agency of the Department of National Defence responding to the scientific and technological needs of the Canadian Forces. The agency is made up of six research centres located across Canada with a corporate office in Ottawa. DRDC has an annual budget of $300 million and employs 1500 people. With a broad scientific program, DRDC actively collaborates with industry, international allies, academia, other government departments and the national security community.

DRDC Suffield is the Canadian centre of expertise in chemical and biological defence and conducts world-class research and development to provide the Canadian Forces with advice, training and equipment to counter the hazards from chemical and biological threats. DRDC Suffield also carries out research and development in military robotics, countermine and the assessment of explosive threats. Scientific and technological activities are supported by a comprehensive biological and chemical laboratories and field experimental capabilities.

About Hemispherx Biopharma

Hemispherx Biopharma, based in Philadelphia, is a biopharmaceutical company engaged in the manufacture and clinical development of new drug entities for treatment of viral and immune-based chronic disorders. Hemispherx's flagship products include Alferon and the experimental immunotherapeutics/antivirals Ampligen(R) and Oragens(R). Alferon is commercially approved for a category of STD infection, and Ampligen(R) and Oragens(R) represent experimental nucleic acids being developed for globally important viral diseases and disorders of the immune system including HPV, HIV, CFS, Hepatitis and influenza. Alferon LDO(TM) is a new experimental drug delivery platform for the Company's commercial product Alferon N(R). Hemispherx's platform technology includes large and small agent components for potential treatment of various viral infections. Hemispherx has in excess of 100 patents comprising its core intellectual property estate covering various forms of double-stranded (ds) RNA and their fields of therapeutic application, a fully commercialized product (Alferon N) and GMP certified manufacturing facilities for its novel pharma products in New Brunswick, New Jersey. 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, Alferon LDO and Oragens(R)) 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(R) do not imply that the product will ever be specifically approved commercially for these other treatment indications.