Hemispherx Filed Patent Applications to Combat SARS.

Business Editors/Health/Medical Writers

PHILADELPHIA--(BUSINESS WIRE)--May 27, 2003

Hemispherx Confirms Filing Patent Applications for the Use of

Alferon N Injection(R) and Ampligen(R) for treating SARS

Hemispherx Biopharma, Inc. (AMEX: HEB) announced today that it filed patent applications covering the use of both of its lead compounds, Alferon N Injection(R) and Ampligen(R) for the potential treatment and prevention of severe acute respiratory syndrome (SARS).

Independent studies have identified Alferon N, a natural source, multispecies alpha interferon product, and Ampligen(R), an experimental, double stranded RNA drug acting potentially as an immunomodulator and antiviral, as first candidates for potentially treating SARS. The patent applications that have been filed provide procedures for combating the effects of coronavirus-induced conditions by the administration of Alferon N Injection(R) or Ampligen(R) or in combination therapy.

The Company believes it has filed its patent applications in a timely matter with respect to its Alferon and Ampligen technologies, protecting its intellectual property and enhancing shareholder value. The patent procedure has also been mentioned in the press release of May 13, 2003, before any other company released potentially competitive patent applications. Hemispherx has a large knowledge and expertise in the procedures of filing patents and has built up, with close to 400 patents, potentially one of the largest patent portfolio in the biotech industry. Due to the acquisition of the Alferon technology, the Company has further enlarged its world wide patent estate with respect to Alferon N Injection(R), including several process patents related to the manufacturing of natural alpha interferon.

About the treatment mechanism

Individuals with chronic diseases or the aged, both conditions associated with weakened cell immunity, are at great risk to accelerated death from SARS. The "spike protein" of coronaviruses further damages the body's immune apparatus, thus facilitating an increase in virus multiplication. The natural immune "cascade" triggered by the patented compounds may modulate these critical deficiencies in host defense.

About Ampligen(R)

Ampligen(R) is an experimental, double stranded RNA drug acting potentially as an immunomodulator and antiviral. Based on in vitro studies, Ampligen(R) is believed to stimulate the immune system as well as destroy viruses directly. The product is currently in Phase 3 clinical trials for the potential treatment of Chronic Fatigue Syndrome (CFS) and in two Phase 2b clinical trials for the potential treatment of HIV/AIDS. SARS, which is believed to be a coronavirus and the HIV virus, both belong to the group of ribose nucleic acid (RNA) viruses which frequently change and mutate. On May 21, 2003 the Company announced the promising data on a NIH sponsored study on SARS finding Ampligen(R) having unusually high and consistent antiviral activity against human coronavirus. The study found Ampligen(R) among the most active drug candidates, compared to approximately 70 others.

About Alferon N

Alferon N (Interferon alfa-n3, human leukocyte derived) is a highly purified, natural source, glycosylated, multispecies alpha interferon product, composed of eight forms of high purified alpha interferon. It is the only natural-source, multispecies alpha interferon currently sold in the U.S. for the treatment of a specific indication of STD (refractory condylomata acuminata) and is also approved for sale in certain other countries, including Hong Kong (Peoples Republic of China) and Singapore. On May 19, 2003 the Company reported positive data from an independent study evaluating the effect of Alferon N in the treatment of pig coronavirus (animal model of SARS). The clinical study showed substantial greater survival rates of treated piglets compared with the control group, receiving placebo. Since human SARS apparently has its roots in animal coronavirus, the Company believes that the drug's effect in the animal study may be relevant to potential human applicability.

About Hemispherx

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. Its flagship products include Alferon and the experimental immunotherapeutics/antivirals Ampligen and Oragens. These novel proteins, approved for a category of STD infection, and experimental nucleic acids are being developed for globally important chronic viral diseases and disorders of the immune system including HPV, HIV, CFS and Hepatitis. Its platform technology includes large and small agent components for potential treatment of various chronic viral infections. Hemispherx has approximately 400 patents comprising its core intellectual property estate, a fully commercialized product (Alferon N) 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) and Oragens(TM)) 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. The Alferon(R) asset for overseas sales for a category of STD is currently being acquired by the Company as part of a multi-step purchase contract of inventory, intellectual property, commercial licenses and GMP approved facilities, which house the biological operations.