New data shows Valortim antibody enhances human T cell response to B. anthracis

PharmAthene, Inc. (NYSE Amex: PIP), a biodefense company developing medical countermeasures against biological and chemical threats, announced today that new data from the Company's Valortim® anthrax anti-toxin program were presented at the 8th Annual ASM Biodefense and Emerging Diseases Research Meeting, held in Baltimore, Maryland, February 21-24, 2010.

The data were presented by Dr. Alan S. Cross, Professor of Medicine and Dr. Subhendu Basu, Assistant Professor, University of Maryland School of Medicine, in a poster presentation entitled Human Adaptive Immune Response to Bacillus Anthracis.  

Valortim® is a fully human anti-toxin monoclonal antibody being developed for the prevention and treatment of inhalational anthrax.  Preclinical studies suggest that Valortim® has the potential to provide protection against anthrax infection when administered prophylactically (prior to the emergence of symptoms of anthrax infection) and also may increase survival when administered therapeutically (once symptoms become evident).

Previous data presented by Drs. Cross and Basu have shown that in addition to inhibiting anthrax toxin, Valortim® appears to augment the immune system's ability to kill anthrax bacilli by enhancing the human dendritic cell response to a challenge with anthrax spores.  These new data expand upon these observations by showing that Valortim® also enhances the human T cell response to B. anthracis. In addition to Valortim's established toxin-neutralizing function, which has been previously described, these studies indicate that it may also assist in enhancing the adaptive immune response to anthrax, which may lead to a reduction and clearance of the bacteria in the host organism.

Dr. Cross remarked, "Our latest research using human immune cells provides additional evidence of the role Valortim® may play in enhancing the elimination of B. anthracis to potentially minimize the severity of infection.  We hypothesize that Valortim® may protect against lethal anthrax infection by its toxin neutralization activity that allows the development of a potent adaptive immune response that facilitates the elimination of harmful bacteria in a host organism."

David P. Wright, President and Chief Executive Officer of PharmAthene, commented, "Drs. Cross and Basu continue to make excellent progress demonstrating how Valortim® may interact with the immune system to potentially minimize the extent and severity of infection with bacillus anthracis.  These data, combined with the accumulating non-clinical efficacy results in animal models, continue to show how Valortim® may have important differentiating benefits, which, if confirmed, may make it a strong choice for procurement consideration in the Strategic National Stockpile."  

The work reported by Drs. Cross and Basu is supported by the Maryland Industrial Partnerships Program (MIPS). The MIPS program was developed to accelerate the commercialization of technology in Maryland by jointly funding collaborative R&D projects between companies and University System of Maryland faculty.