Hemispherx Biopharma Announces Test of Ampligen® with FluMist

Hemispherx Biopharma Announces Test of Ampligen® with FluMist

…. First Intranasal Administration in Humans

Philadelphia, PA, Monday, April 30, 2012: Hemispherx Biopharma, Inc. (NYSE Amex: HEB) (the "Company" or "Hemispherx"), announced that Ampligen®, an experimental immunotherapeutic, has been nasally administered in conjunction with FluMist® to healthy human volunteers in a study being conducted at the University of Alabama at Birmingham under the auspices of Dr. Paul Goepfert, Associate Professor of Medicine in the Division of Infectious Diseases and Director of the Alabama Vaccine Research Clinic.

The study, a first use of Ampligen® nasally delivered with a vaccine in humans, is "to assess the safety of Ampligen® when used with a nasally delivered seasonal vaccine", said Dr. David Strayer, Chief Medical Officer at Hemispherx. "This study advances the pioneering work of Dr. Hideki Hasegawa, Director, Department of Pathology, National Institute of Infectious Diseases in Japan, regarding a pandemic H5N1 flu vaccine delivered intra-nasally to rodents and primates along with Ampligen®. The study will also evaluate potential immunologic enhancement by comparing immune parameters in the group receiving Ampligen® plus FluMist® with another group receiving FluMist® plus placebo. We intend to conduct a broad array of immune tests to compare the immune response for both its magnitude and breadth". One objective is to determine the extent to which Ampligen® may mobilize potential protections against pandemic influenza when used in conjunction with a seasonal flu vaccine.

Dr. Goepfert stated that "the normal route of transmission of the flu virus is through the nasal passage. We are excited about commencing this study, which utilizes the mucosal immune system and thus offers significant potential to protect large numbers of individuals by administering enhanced flu vaccines. In his animal studies, Dr. Hasegawa showed that Ampligen® helped to expand viral epitope recognition and thereby provided cross-protection to flu virus strains which were not expected to be conveyed by the administered vaccine."

To highlight the importance of this work, Suzanne Clancy, Ph.D., in a 2008 paper on "Genetics of the Influenza Virus" in Nature Education wrote that:

"In the United States, seasonal influenza epidemics typically claim the lives of about 30,000 people each year and cause hospitalization of more than 100,000 (Reid & Tautenberger, 2003). Every two or three years, more virulent strains circulate, increasing death tolls by approximately 10,000 to 15,000 individuals. These seasonal epidemics are the result of antigenic drift, a phenomenon caused by mutations in two key viral genes due to an error-prone RNA polymerase.

Less frequently, however, new and particularly virulent strains of influenza arise, which cause worldwide pandemics that are accompanied by greatly increased death tolls. These strains occur because of the phenomenon known as antigenic shift, in which humans are infected with avian influenza viruses or viruses that contain a combination of genes from human and avian sources. Since 1900, three of these pandemics have occurred. The first, which took place in 1918 and was referred to as "Spanish" influenza, was the deadliest, claiming an estimated 40 million lives worldwide in less than a year (Palese, 2004). Unlike weaker flu strains that are more of a threat to the elderly, this virus claimed the lives of many young people, including children and young adults. In fact, people under age 65 accounted for 99% of the deaths attributed to this strain, whereas subsequent pandemics claimed many fewer people from this age group. Later epidemics occurred in 1957, when the "Asian" flu killed 70,000 people in the United States, and in 1968, when the "Hong Kong" strain killed 30,000 Americans (Reid & Tautenberger, 2003)."

Highly pathogenic avian H5N1 viruses have extraordinary lethality in humans. Human disease has been limited thus far due to the inability of those viruses to infect the upper airways of humans – although there has been concern that viral mutations could provide this capacity. Late last year scientists in Wisconsin and the Netherlands successfully mutated the H5N1 virus so that it can more easily spread among humans (Nature News 20th December, 2011). This research was done to test the potential for avian H5N1 to mutate into a form that can spread easily in humans through coughing or sneezing. Nevertheless it has caused concern that such work may get into the hands of potential bio-terrorists and/or accidentally be released from experimental labs into the general environment. The current human trial at the University of Alabama will provide the first data in humans whether the epitope expansion observed by Dr. Hasegawa in experimental animals occurs in humans.

It is hoped that FluMist® combined with an effective adjuvant might be able to provide easily administered protection even against mutated strains of flu virus. Successful enhancement of immune responses in the current study group of young adults by Ampligen would provide justification for extension of studies to the elderly who, as a group, could benefit greatly from more effective vaccines.

About Hemispherx Biopharma
Hemispherx Biopharma, Inc. is an advanced specialty pharmaceutical 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® (FDA approved for a category of sexually transmitted diseases) and the experimental therapeutics Ampligen® and Alferon® LDO. Ampligen® is an experimental RNA nucleic acid being developed for globally important debilitating diseases and disorders of the immune system. Hemispherx's platform technology includes components for potential treatment of various severely debilitating and life threatening diseases. Hemispherx has 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 commercial products. For more information please visit www.hemispherx.net.

Hemispherx Biopharma, Inc.,
Dianne Will, Investor Relations
(518) 398-6222, [email protected]

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.