Hemispherx Reports Positive Independent Study Results of Alferon N in the Treatment of Pig Coronavirus -Animal Model of SARS-.

Business Editors/Health/Medical Writers

BIOWIRE2K

PHILADELPHIA--(BUSINESS WIRE)--May 19, 2003

Hemispherx Biopharma, Inc. (AMEX: HEB)--

-- Amsterdam Group proves Koch's Postulates on Human Coronavirus

(SARS)

-- Clinical Study Shows Significantly Greater Survival Rates of

Treated Piglets in Natural Outbreaks Low Dose Alferon N

Effective within 4 days of Treatment

Hemispherx Biopharma, Inc. (AMEX: HEB) reports the results of a "double-blinded" independent study conducted in a pig population suffering from the pig coronavirus, after therapeutic intervention with one of the Company's lead Products, Alferon N. Newborn piglets, treated with Alferon N, even in low doses, had significantly greater survival rates than placebo-treated, control, piglets.

Recent tests, May 14, 2003, at the Erasmus Medical Center, Amsterdam, confirm "the proof that a coronavirus is the primary cause of the disease" (human SARS) by fulfilling Koch's Postulates thru the serial steps of coronavirus isolation (from man), reintroduction of virus and recreation of disease in macaque monkeys.

About SARS Models in Animals

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. However, further independent investigation is required to evaluate safety and efficacy in humans. In man, mortality with SARS can exceed 50% in certain age groups.

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 condylomata HPV and is also approved for sale in certain other countries, notably including Hong Kong (Republic of China) and Singapore.

About the Clinical Study in Farm Animals

Transmissible coronavirus is a devastating disease in piglets, especially in high-density living facilities, and can result in high mortality, even approaching 100% mortality in piglets less than 14 days of age. The Study was conducted in a piglet population of 1740 animals in Texas, U.S.A., living under typical field/farm conditions. During a natural outbreak of Pig Coronavirus, groups of piglets were treated for 4 consecutive days with placebo or 1.0, 10.0 or 20.0 international units of Alferon N. Survival data were analyzed by age of treatment and dosage. All dosages of Alferon N improved survival rates (p (less than) 0.01) and certain groups (higher dosage) had very significantly greater (p (less than) 0.001) survival rate of 94.6% (p (less than) 0.001 means that the probability of the results being by chance alone is less than 1 in 1000). Thus, Alferon N therapy modulates the natural course of otherwise very high morbidity and mortality commonly seen with Pig Coronavirus infections. In contrast, vaccination of pigs still results in unacceptable high death rates, suggesting that natural alpha interferon, such as Alferon, may be a superior treatment approach to nature porcine coronavirus outbreaks.