October 15, 2008

PharmAthene Announces $1.6 Million Congressional Appropriation for Continued Development of Protexia(R)

ANNAPOLIS, Md., Oct. 15 /PRNewswire-FirstCall/ -- PharmAthene, Inc. , a biodefense company developing medical countermeasures against biological and chemical threats, announced today that the Consolidated Security, Disaster Assistance, and Continuing Appropriations Act, 2009, which includes the full-year FY 2009 appropriations for the Department of Defense (DoD), includes $1.6 million to support ongoing development of the Company's broad spectrum chemical nerve agent countermeasure, Protexia(R).

"We continue to be pleased by the strong support we have received from the Department of Defense in the advancement of our biodefense programs," said David P. Wright, President and Chief Executive Officer. "The appropriations funding announced today is in addition to a previously announced multi-year contract from the Department of Defense U.S. Army Space and Missile Command for advanced development of Protexia(R). This contract is valued at up to $219 million, provided that certain milestones are achieved, and all contract options and extensions are exercised by the government."

"We are also grateful to Maryland's U.S. Senator Benjamin Cardin, who has been very supportive and committed to our success in developing biodefense vaccines and therapeutics to protect America's citizens and military personnel," continued Mr. Wright. "Senator Cardin has been a strong advocate for promoting the growth of technology-focused industries within Maryland and understands the importance of supporting our Nation's biodefense industry."

Protexia(R), a recombinant pegylated version of human butyrylcholinesterase (BChE), is being developed as a pre-exposure prophylactic and post-exposure therapy for military and civilian victims of nerve agent attacks.

"We have obtained promising data in animal models that demonstrate the effectiveness of non-pegylated rBChE in preventing toxicity and death from exposure to a broad spectrum of chemical nerve agents," commented Dr. John Troyer, Senior Program Director for Protexia(R). "Last week, at the Public Health Emergency Medical Countermeasures Enterprise (PHEMCE) Stakeholder's Workshop, we presented new preliminary findings which suggest that non- pegylated rBChE may also have efficacy as a therapeutic against nerve agent exposure. We're very encouraged by these data, and expect to shortly begin a Phase I study of Protexia(R) (pegylated rBChE) to evaluate its safety in humans."

"Our advanced development contract is administered through the Chemical Biological Medical Systems (CBMS) group within the DoD," said Dr. Troyer. "CBMS remains at the forefront of the development of novel medical countermeasures and we are pleased to work collaboratively with them on our Protexia(R) development program."

About Protexia(R)

Protexia(R) is a recombinant version of human butyrylcholinesterase (BChE), a naturally occurring protein found in minute quantities in blood (2 mg/liter). BChE functions as a natural bioscavenger, like a sponge, to absorb and degrade organophosphate poisons (e.g. nerve agents) before they cause neurological damage. Protexia(R) is being developed as a pre-exposure prophylactic and post-exposure therapy for casualties on the battlefield and civilian victims of nerve agent attacks. Nerve agents belong to a class of compounds known as organophosphate (OP) agents. OP nerve agents, such as sarin gas, soman, tabun or VX, enter the blood stream via inhalation or absorption through the skin. The nerve agents travel in the circulatory system to the brain and muscles causing the nerves to become over-stimulated which lead to massive convulsions and death in severe cases.

About Chemical Nerve Agents

Organophosphorous nerve agents, or anti-cholinesterase agents, were discovered in the 1930s following intensive research into new insecticides. Their discovery represents the beginning of modern chemical warfare. These agents cause toxicity by binding to and inhibiting acetylcholinesterase, an enzyme in the body that is essential for nervous system function, leading to increases in acetylcholine and "cholinergic crisis" that can cause loss of muscle control, respiratory failure, paralysis, convulsions, permanent brain damage and eventually death.

These so-called nerve gases, which are actually all liquids at room temperature, are lethal far more quickly and in far lower concentrations than other classical chemical warfare agents such as vesicants, choking agents and blood agents, and are effective both when inhaled and when absorbed through the skin. Nerve agents can be classified as either G-agents (sarin, soman, tabun) or V-agents (VX), both of which are exceedingly toxic.

About PharmAthene, Inc.

PharmAthene was formed to meet the critical needs of the United States and its allies by developing and commercializing medical countermeasures against biological and chemical weapons. PharmAthene's lead product development programs include:

-- SparVax(TM) -- a second generation recombinant protective antigen (rPA) anthrax vaccine

-- Third generation rPA anthrax vaccine

-- Valortim(R) -- a fully human monoclonal antibody for the prevention and treatment of anthrax infection

-- Protexia(R) -- a novel bioscavenger for the prevention and treatment of morbidity and mortality associated with exposure to chemical nerve agents

   -- RypVax(TM) -- a recombinant dual antigen vaccine for plague     For more information about PharmAthene, please visit http://www.pharmathene.com/.    Statement on Cautionary Factors  

Except for the historical information presented herein, matters discussed may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to certain risks and uncertainties that could cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Statements that are not historical facts, including statements preceded by, followed by, or that include the words "potential"; "believe"; "anticipate"; "intend"; "plan"; "expect"; "estimate"; "could"; "may"; "should"; or similar statements are forward-looking statements. PharmAthene disclaims, however, any intent or obligation to update these forward-looking statements. Risks and uncertainties include risk associated with the reliability of the results of the studies relating to human safety and possible adverse effects resulting from the administration of the Company's product candidates, unexpected funding delays and/or reductions or elimination of U.S. government funding for one or more of the Company's development programs, the award of government contracts to our competitors, unforeseen safety issues, unexpected determinations that these product candidates prove not to be effective and/or capable of being marketed as products, as well as risks detailed from time to time in PharmAthene's Forms 10-K and Form 10-Q under the caption "Risk Factors" and in its other reports filed with the U.S. Securities and Exchange Commission (the "SEC"). In particular, to date we have not commenced a human clinical trial for Protexia(R), and the studies described above constitute non-clinical animal studies. Significant additional non-clinical animal studies, human clinical trials, and manufacturing development work remain to be done. At this point there can be no assurance that this product candidate will be shown to be safe and effective and approved by regulatory authorities for use in humans. Copies of PharmAthene's public disclosure filings are available from its investor relations department and our website under the investor relations tab at http://www.pharmathene.com/.

PharmAthene, Inc.

CONTACT: Stacey Jurchison of PharmAthene, Inc., +1-410-269-2610,[email protected]

Web site: http://www.pharmathene.com/