Hemispherx Biopharma Announces New Publication Enlarges the Understanding of Ampligen(R) Safety Profile Across Diverse Animal Species and Focuses on the Unique TLR-3 Receptor/Ampligen(R) Interaction

PHILADELPHIA, April 8, 2014 (GLOBE NEWSWIRE) -- Hemispherx Biopharma, Inc. (NYSE:HEB) (the "Company" or "Hemispherx") announced today the peer-reviewed publication titled "Discordant Biological and Toxicological Species Responses to TLR-3 Activation" in the current issue of the American Journal of Pathology Vol. 184 (pages 1062-1072), 2014.

Toll-like receptors (TLR) are multiple proteins of the innate immune system that trigger upon activation cascades (release) of disease fighting molecules, which include enhancement of the body's immunity and interruption of the replication cycles of many different viruses. Ampligen®, an experimental therapeutic, initiates its pharmacological effects by binding TLR-3 selectively. The selectivity/ specificity of Ampligen® was first fully described by the late Nobel Laureate in Medicine, Professor Ralph Steinman of the Rockefeller University. The biological significance of the extraordinary specificity of Professor Steinman's findings is illustrated in the current manuscript.

For example, all other TLR stimulators thus far studied clinically (e.g., CpG, Flagellins, etc.) trigger more pro-inflammatory cascades, which may lead to a significant side effect profile in patients.

In contrast, Ampligen®, an experimental therapeutic, displayed a discordance between the rodent and human inflammatory responses. Systemic inflammatory cytokines, observed in rats, were correlated with significant acute and chronic in vivo toxicities at Ampligen® doses that elicited no detectable systemic inflammatory cytokines and minimal toxicities in primates. The lack of systemic cytokine detection is consistent with the observed minimal toxicity in primates, in contrast to the significant toxicities observed in non-primates. Rat toxicity correlates with systemic cytokine levels, and the lack of primate toxicity similarly is correlated with the lack of significant systemic inflammatory cytokine levels.

Inflammatory cytokines observed in the systemic circulation in rats are associated with toxicity and are analogous to the toxicity seen in humans with lethal viral infections, such as highly pathogenic avian influenza and severe acute respiratory syndrome-CoV associated with inflammatory cytokine storms.

Cytokine responses from baseline in seventy-six (76) patients with CFS enrolled in two clinical trials of Ampligen® were also examined at 32 weeks post-treatment with only one patient exhibiting a relatively high systemic TNF-α (Tumor Necrosis Factor Alpha) level. TNF-α is a cytokine with high inflammatory activity.

In summary, primates including humans display a relatively down-regulated inflammatory cytokine induction pathway with TLR-3 receptor stimulation secondary to Ampligen® administration. This down regulatory effect may contribute to the favorable safety profile observed clinically with Ampligen®, an experimental therapeutic.

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 Company's Alferon N 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

To the extent that statements in this press release are not strictly historical, all such statements are forward-looking, and are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Words such as "intends," "plans," and similar expressions are intended to identify forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by Hemispherx that any of its plans will be achieved. These forward-looking statements are neither promises nor guarantees of future performance, and are subject to a variety of risks and uncertainties, many of which are beyond Hemispherx's control, which could cause actual results to differ materially from those contemplated in these forward-looking statements. Examples of such risks and uncertainties include those set forth in the Disclosure Notice, below, as well as the risks 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. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Hemispherx undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise revise or update this release to reflect events or circumstances after the date hereof.

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. 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. The clinical studies referenced herein have been previously reviewed by the FDA and are not, in and of themselves, a sufficient basis for approval. 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 and/or any other activities could vary materially from Hemispherx's expectations.

CONTACT: Company/Investor Contact: Charles Jones CJones & Associates Public Relations 888-557-6480 cjones@cjonespr.comSource:Hemispherx Biopharma, Inc.