PHILADELPHIA, April 4, 2011 (GLOBE NEWSWIRE) -- Hemispherx Biopharma (NYSE Amex:HEB) announced new data presented yesterday at the American Association for Cancer Research ("AACR") 102nd Annual Meeting 2011 in Orlando (Abstract No. 748) by investigators from the Tumor Vaccine Group ("TVG") at the University of Washington in Seattle, WA, which highlights the potential of Ampligen® to act as a potent tumor vaccine adjuvant.
Ampligen® [rintatolimod; poly(I)·poly(C12,U)], an experimental therapeutic, has previously been shown to be a potent and selective agonist of Toll-like receptor 3 ("TLR3"). In these new studies, the adjuvant effect of Ampligen® was evaluated in a transgenic mouse breast cancer model. In this model, the mice were vaccinated with a combination of anti-tumor peptide vaccine and Ampligen®, with peptides alone, with Ampligen® alone, and with carrier as a negative control. Other potential vaccine adjuvant candidates, GM-CSF, imiquimod (a TLR7 agonist), and CpG ODN 2395 (a TLR9 agonist), were also studied, in addition to Ampligen, in this study. After vaccination, the mice were challenged with tumor cells and tumor growth was monitored.
The results demonstrated that vaccination with Ampligen® combined with the peptide "...remarkably inhibited tumor growth by 60%." In the study, CpG, GM-CSF and Ampligen® all significantly inhibited the growth of tumors as compared with peptides alone (p<0.002). Among these three reagents, Ampligen® more significantly inhibited tumor growth as compared with CpG (p=0.02). Moreover, Ampligen® made a greater mean contribution to anti-tumor effect as compared with GM-CSF, but that difference was not statistically significant (p=0.415). (The mean percentage of tumor inhibition with adjuvant use of CpG, GM-CSF and Ampligen® was 37%, 53% and 60%, respectively.) This study results also showed that imiquimod failed to stimulate an anti-tumor effect. The authors conclude that "Ampligen® as an adjuvant inhibited the growth of breast cancer with an increased level of Th1 cytokines and is a potent tumor vaccine adjuvant with the potential for clinical use."
The TVG at the University of Washington is a multidisciplinary group of investigators focused on the diagnosis, prevention, and treatment of cancer with novel, immune-based therapies including cancer vaccines. TVG is directed by Dr. Mary L. Disis, who is Professor of Medicine, Associate Dean for Translational Science in the University of Washington School of Medicine and a Member of the Fred Hutchinson Cancer Research Center.
Dr. William A. Carter, Chairman and CEO, stated, "We are enthusiastic about the data that Professor Disis and her colleagues have generated. Her work focuses on the development of vaccines and cellular therapies for breast and ovarian cancer. Their approach provides a great opportunity for integrating Ampligen into cancer vaccines strategies and advancing Ampligen as a cancer vaccine adjuvant into clinical trials."
Hemispherx views the potential use of Ampligen® as a component of cancer immunotherapy as an important development opportunity. The Company's near term focus in cancer is to initiate a series of collaborations with cancer research experts at premier institutions to help define the best mode of integrating Ampligen® into immunotherapy strategies for the treatment of cancer.
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.
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 pre-clinical or clinical trials do not imply that any study product will ever be approved commercially for the studied or other treatment indications.