Low Natural Killer (NK) Activity Observed Across the Chronic Fatigue Syndrome (CFS) Disease Spectrum

PHILADELPHIA, Jan. 12, 2015 (GLOBE NEWSWIRE) -- Hemispherx Biopharma, Inc. (NYSE MKT:HEB) (the "Company" or "Hemispherx"), reported today that it has conducted new in vitro studies of natural killer (NK) cells obtained from CFS patients in conjunction with a comprehensive review of the medical literature to determine the relative incidence of NK cell functional deficiencies in CFS disease. This review indicates that low NK cell cytotoxicity (NKCC) has been consistently reported in CFS patients compared to normal controls. In the new laboratory studies, Ampligen® (rintatolimod), an experimental therapeutic, was found to increase in vitro NK activity utilizing cells from CFS patient donors. The authors of the new report are all affiliated with Hemispherx.

NK cells are an important component of the innate immune response and may play an important role as a surveillance mechanism against viruses, other microbial pathogens, and tumor cells (Herberman, et al. Science 1981; 214:24-30). CFS is a debilitating disorder, characterized by disabling fatigue, flu-like symptoms, recurrent infections, and an apparent increased incidence of certain cancers, including lymphomas and brain tumors (Levine, et al. Ann Epidemiol 1998;8:245-249). The vast majority (88%) of published studies (15 of 17) evaluating NKCC in patients meeting Centers for Disease Control (CDC) disease criteria for CFS concluded that CFS is associated with a reduction in NKCC compared to healthy controls. Two of the studies that did not find a difference in NKCC between CFS patients and normal controls appear to contain design flaws, which may have influenced results, for example, including the exclusion of CFS patients sick for 10 years or longer. Notably, studies at the University of Miami (176 CFS patients) found a range of 2 to 25 years from onset of CFS symptoms with an average of 10 years (Fletcher, et al. PLoS One 2010; 5(5):e10817).

The medical literature indicates that the mean percent decrease in NKCC for the CFS population as defined using the CDC 1988 diagnostic criteria is significantly greater than that for the CFS patients defined by the CDC 1994 diagnostic criteria (the CDC 1988 criteria require more symptomatology to meet the requirements for a CFS diagnosis). Multiple published studies presented data, which support a relationship between a lower NKCC and a higher level of CFS symptom severity.

Ampligen® (rintatolimod), an experimental therapeutic, increased mean NK cell activity in vitro over 100% in the fifteen (15) CFS patients who donated NK cells. The mean age of the subject population was 48 years and two-thirds of the subjects were female. The observed NKCC increase was achieved with concentrations of Ampligen® achievable with a standard clinical treatment regimen of 400 mg given twice weekly. More than 100,000 doses have been given clinically, principally to CFS patients.

Historically, Hemispherx's double-blind, placebo-controlled and open-label clinical trials in CFS have emphasized quantitative measures of increased physical performance. For example, in a Phase III trial comparing twice weekly IV Ampligen® vs. placebo conducted in 234 subjects with long-standing debilitating CFS, the primary endpoint was intra-patient change from baseline at week 40 in exercise tolerance (ET). Subjects receiving Ampligen® for 40 weeks improved intra-patient placebo adjusted ET 21.3% from baseline in an intent-to-treat analysis. Correction for subjects with reduced dosing compliance increased placebo adjusted improvement to 28% (p=0.022) (Strayer, et al. PLoS ONE 7(3):e31334. doi:10.1371/journal.pone.0031334). The improvement observed represented approximately twice the minimum considered medically significant by regulatory agencies.

An FDA Advisory Committee, convened in December 2012, when asked "Is the safety profile of Ampligen® adequate for approval for the treatment of CFS?", the "Yes" vote was 8, and the "No" vote was 5. When asked has the application "provided sufficient efficacy and safety data to support marketing of Ampligen® for the treatment of chronic fatigue syndrome?", the "Yes" vote was 5 and the "No" vote was 8. Thereafter, the Agency declined to approve the marketing application. Subsequently, the Company has been in dialogue with the Agency as well as selected regulatory authorities worldwide regarding potential paths forward to advance the experimental product for potential treatment of severe CFS.

The evidence that severity of CFS is associated with progressive derangement of immune surveillance mediated by NK cells may afford a new path to identify opportunities for CFS therapeutic intervention. While NK studies were not systematically performed in the earlier well-controlled clinical study cited in the PLoS One peer-reviewed publication, improvements in vitality score, Activities of Daily Living score, and reduction in concomitant medications usage were observed. Quality-of-life improvements may be sequelae of improved immunosurveillance.

About Ampligen®

Ampligen®, 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 especially life-threatening viruses. 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 including cancers. 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.

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 and abroad. 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 Ampligen® 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. No evidence has suggested that Ampligen® will ever be commercially approved for the new potential treatment indications, including, but not limited, to the treatment of CFS.

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, above, 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. No evidence is suggested that Ampligen® will ever be commercially approved for the CFS treatment indications mentioned in this release.

CONTACT: Company/Investor Contact Charles Jones CJones & Associates Public Relations Office: 888-557-6480 Cell: 305-987-7418 Email: cjones@cjonespr.comSource:Hemispherx Biopharma, Inc.