Source: Hemispherx Biopharma, Inc.

FDA Authorizes Expansion of Ampligen/FluMist Intranasal Clinical Trial Designed to Elicit Potential Protection Against Many Pre-Pandemic Influenza Viruses

Data Monitoring Committee Also Supports Expansion of Clinical Tests

PHILADELPHIA, Dec. 9, 2013 (GLOBE NEWSWIRE) -- Hemispherx Biopharma, Inc. (NYSE MKT:HEB) (the "Company" or "Hemispherx") today announced that its Phase 1/2 clinical trial at the University of Alabama Vaccine Research Clinic is now being expanded based on an analysis of safety results to date conducted by both the Food and Drug Administration ("FDA") and a Data Monitoring Committee, the latter group comprised of a team of independent clinical, basic research, and statistical professionals.

The ongoing clinical study is the first extension to humans of preclinical studies, previously published in the peer-reviewed literature, indicating that the combination of Ampligen® (an experimental therapeutic) with commercially available seasonal influenza vaccine when applied intranasally, may provide enhanced protection against certain potentially pandemic influenza strains (Ichinohe T, et al. 2007, JID 196:1313-1320).

The Spanish flu pandemic killed between 20 and 100 million people in 1918-1919, a similar epidemic based on the worldwide population in 2004 has been estimated to result in approximately 60 million deaths (Murray CJ, et al. 2006, Lancet 368:2211-2218). Influenza often leads to death in patients suffering from underlying diseases; complications are especially prevalent in the elderly population. Hence, the objective of identification of an influenza vaccine and/or vaccine adjuvant "cocktail" offering broad-spectrum protective properties (sometimes referred to as a "Universal flu vaccine"), remains one of the highest public health priorities. Successful animal experimentation does not necessarily predict clinical effectiveness and no assurance can be given that the projected clinical tests will demonstrate either acceptable safety or efficacy.

The pioneering preclinical influenza research was conducted over several years at the Japanese National Institutes of Health (JNIH) under the direction of Dr. Hideki Hasegawa, Director, Department of Pathology. The research was conducted under a standard Material Transfer Agreement with the Company, and Dr. Hasegawa was an independent investigator who received no financial support from Hemispherx for his experimental work.

The expanded clinical study includes a search for immune molecules elicited by the treatment drugs which may be protective against pandemic and pre-pandemic influenza strains. In the cited preclinical studies with Ampligen®, a broad range of potentially protective immune molecules were identified in both nasal washings as well as in the blood stream. In animals, the elicitation of both adaptive immunity molecules (immunoglobulins IgA and IgG) as well as innate immunity mechanisms (e.g., natural killer (NK) cells) have been detected as secondary to Ampligen®'s mechanism of action.

On April 30, 2012, when the first stage of the study received FDA authorization, Dr. Goepfert, Associate Professor of Medicine in the Division of Infectious Diseases and Director of the Alabama Vaccine Research Clinic, 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."

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. 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 Company believes that the expanded human trial at the University of Alabama will provide the first data in humans as to whether the epitope expansion observed by Dr. Hasegawa in experimental animals occurs in humans. Successful animal experimentation does not necessarily predict clinical effectiveness and no assurance can be given that the projected clinical tests will demonstrate either acceptable safety or efficacy.

It is anticipated that FluMist® combined with an effective adjuvant may be able to provide easily administered protection in humans even against mutated strains of flu virus including both H7N9 and H5N1 strains. Successful enhancement of immune responses in the current study group of young adults by Ampligen®, an experimental therapeutic, 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® 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, including Chronic Fatigue Syndrome. Hemispherx's platform technology includes components for potential treatment of various severely debilitating and life threatening diseases. Because both Ampligen® and Alferon® LDO are experimental in nature, they are not designated safe and effective by a regulatory authority for general use and are legally available only through clinical trials. Hemispherx has patents comprising its core intellectual property estate and a fully commercialized product (Alferon N Injection®), approved for sale in the U.S. and Argentina. The FDA approval of Alferon N Injection® is limited to the treatment of refractory or recurrent external genital warts in patients 18 years of age or older. The Company's Alferon N Injection® approval in Argentina includes the use of Alferon N Injection® (under the brand name "Naturaferon") for use in any patients who fail, or become intolerant to recombinant interferon, including patients with chronic active hepatitis C infection. 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.

Forward-Looking Statements

The foregoing release contains forward-looking statements that can be identified by words such as "will be, investigative, interim, potential" or similar terms, or by express or implied discussions regarding potential efficacy for Hemispherx's Ampligen®, or regarding potential future revenues from Ampligen®. You should not place undue reliance on these statements. Such forward-looking statements are based on the current beliefs and expectations of Management regarding future events, and are subject to significant known and unknown risks and uncertainties. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those set forth in the forward-looking statements. There can be no guarantee that Ampligen® will receive regulatory approval or be commercially successful in the future. In particular, management's expectations regarding Ampligen® could be affected by, among other things, the uncertainties inherent in research and development, including unexpected clinical trial results and additional analysis of existing clinical data and failure of the clinical results to confirm the predictions of the animal studies; unexpected regulatory actions or delays or government regulation generally; the Company's ability to obtain or maintain proprietary intellectual property protection; general economic and industry conditions; global trends toward health care cost containment, including ongoing pricing pressures; unexpected manufacturing issues, and other risks and factors described in Hemispherx's filings with the Securities and Exchange Commission, including the most recent reports on Forms 10-K, 10-Q and 8-K on file with the U.S. Securities and Exchange Commission, and in the Disclosure Notice below. Hemispherx is providing the information in this press release as of this date and does not undertake any obligation to update any forward-looking statements contained in this press release as a result of new information, future events or otherwise.

Disclosure Notice

The information in this press release includes certain "forward-looking" statements including without limitation statements about additional steps which the FDA may require and Hemispherx may take in continuing to seek commercial approval of the Ampligen® NDA for the treatment of Chronic Fatigue Syndrome in the United States or in other countries. The production of new Alferon® API inventory will not commence until the capital improvement and validation phases are complete. While the facility is approved by FDA under the Biological License Application ("BLA") for Alferon®, this status will need to be reaffirmed upon the completion of the facility's enhancements prior to commercial sale of newly produced inventory product. If and when we obtain a reaffirmation of FDA BLA status and have begun production of new Alferon® API, we will need FDA approval as to the quality and stability of the final product to allow commercial sales to resume. The final results of these and other ongoing activities could vary materially from Hemispherx's expectations and could adversely affect the chances for approval of the Ampligen® NDA in the United States and other countries. Any failure to satisfy the FDA regulatory requirements or the requirements of other countries could significantly delay, or preclude outright, approval of the Ampligen® NDA in the United States and other countries. 

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, changes 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. The final results of these efforts could vary materially from Hemispherx's expectations.