Antibodies Against Flu Strains With Pandemic Potential Observed

PHILADELPHIA, PA, USA I September 15, 2014 I Hemispherx Biopharma, Inc. (NYSE MKT:HEB) (the “Company” or “Hemispherx”), announced today a peer-reviewed publication entitled “Intranasal Seasonal Influenza Vaccine and a TLR-3 Agonist, Rintatolimod, Induced Cross-Reactive IgA Antibody Formation Against Avian H5N1 and H7N9 Influenza HA in Humans” (Vaccine (2014), http://dx.doi.org/10.1016/j.vaccine.2014.07.078). The authors of the publication include staff of Hemispherx.

The combination of the intranasal FluMist(R) along with the rintatolimod generated specific secretory IgA responses of at least 4 fold over baseline against at least one of the homologous vaccine strains included in the vaccine in 92% of the study subjects. Additionally, this vaccination strategy induced cross-reactive secretory IgA against highly pathogenic avian influenza virus strains H5N1, H7N9, and H7N3 with pandemic potential for humans. The combination of rintatolimod and FluMist(R) was well tolerated.

This clinical effort is the culmination of several years of research including primate testing on the development of a broad spectrum, pandemic influenza vaccine, initiated at the Japanese National Institute of Infectious Diseases, Tokyo, Japan. Rintatolimod (Ampligen(R)), a synthetic double-stranded RNA (Poly I : Poly C12U), is a well-defined selective Toll-like receptor 3 agonist in the induction of innate immune responses. The present clinical work is in collaboration with the University of Alabama Vaccine Research Clinic, Birmingham, Alabama. The present research is being conducted with FluMist(R), a commercially available intranasal seasonal influenza vaccine.

The purpose of this clinical trial funded by Hemispherx is to assess the safety and impact of rintatolimod on intranasal influenza vaccine in healthy adults. During Stage I of this Phase I/II clinical trial, volunteers were immunized intranasally with 3 doses of FluMist(R) seasonal influenza vaccine followed by intranasal rintatolimod 3 days after each FluMist(R) dose. Parotid saliva and nasal wash samples were collected and tested for specific antibodies directed against the homologous FluMist(R) viral hemagglutinins (HAs), as well as, avian influenza H5N1 and H7N3 viral HAs.

The next phase of this research will focus on comparing the immunogenicity of FluMist(R) combined with placebo and two different dosage levels of rintatolimod.

Successful animal experimentation, and these initial human data, do not necessarily predict clinical effectiveness and no assurance can be given that further clinical tests will demonstrate either acceptable safety or efficacy and there is no assurance of it being approved for commercial sales.

About Ampligen(R)

Ampligen(R), an experimental therapeutic, is a new class of specifically-configured ribonucleic acid (RNA) compounds targeted as potential treatment of diseases with immunologic defects and/or viral causation.

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(R) and the experimental therapeutics Ampligen(R) and Alferon(R) LDO. Ampligen(R) 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(R) and Alferon(R) 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(R)), approved for sale in the U.S. and Argentina. The Company’s Alferon(R) N approval in Argentina includes the use of Alferon N Injection(R) (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

SOURCE: Hemispherx