PharmAthene Completes Closing Arguments and Provides Update on Litigation With SIGA Technologies

ANNAPOLIS, Md. -- PharmAthene, Inc. (NYSE Amex: PIP) announced today that closing arguments in its breach of contract action against SIGA Technologies were held on Friday, April 29, 2011 in the Delaware Court of Chancery.  Post trial briefs in the case were submitted by both parties to the Court in April 2011.

Eric I. Richman, President and Chief Executive Officer of PharmAthene, commented, "PharmAthene is pleased with how our legal team presented our case and that the evidence is in and the case is before the Vice Chancellor.  PharmAthene looks forward to the Court's decision."

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"; "will"; "project"; "potential"; or similar statements are forward-looking statements. PharmAthene disclaims any intent or obligation to update these forward-looking statements other than as required by law.  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, challenges related to the development, scale-up, technology transfer, and/or process validation of manufacturing processes for our product candidates, 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 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, there can be no assurance that the Company will prevail in its lawsuit against Siga, or that even if the court rules in the Company's favor, the court will award monetary damages or other remedies adequate to fully compensate the Company for its loses.

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