PharmAthene, Inc. Presents SparVax® Anthrax Vaccine Data At The New Technologies New Vaccines 2014 Conference

ANNAPOLIS, Md., April 1, 2014 /PRNewswire/ -- PharmAthene, Inc. (NYSE MKT: PIP) announced today that data from the Company's SparVax^® next-generation anthrax vaccine program were recently presented at the 8^th Annual New Technologies, New Vaccines conference. In a presentation entitled, "Factors that Affect Potency and Stability for a Recombinant Protective Antigen Vaccine," Dr. Bradford Powell, Director, Analytical Sciences at PharmAthene, presented results demonstrating the Company's achievements in developing key analytical assays which are being employed to monitor the stability and potency of SparVax^®.

"We believe SparVax^® is a promising alternative to the current anthrax vaccine and other rPA-based vaccines due, in part, to its unique formulation. This formulation, and our development of newer, more precise assays have facilitated the development and testing of a vaccine product with enhanced stability and potency," said Dr. Powell. "Further, our research has demonstrated that subtle changes in the interaction between rPA and an immune-stimulating adjuvant (Alhydrogel^®) yield important improvements in stability and immunogenicity."

Data presented by Dr. Powell show how the addition of phosphate alters the surface chemistry of the immune-stimulating adjuvant, Alhydrogel^® in such a way that the stability profile of rPA is improved and potency is increased, as compared to vaccine formulations with less phosphate. In addition, the phosphate/Alhydrogel^® formulation demonstrated five-fold higher potency than a comparable low phosphate formulation, as tested in the prior mouse challenge assay.

The need for newer anthrax vaccines based on modern vaccine technology, which offer the potential for improved safety, convenience and cost-effectiveness, is widely acknowledged. SparVax^® is a next-generation anthrax vaccine being developed for pre- and post-exposure protection against anthrax. It is based on recombinant protective antigen (rPA), the principal virulence factor of the bacterial organism, B. anthracis (anthrax).

PharmAthene's rPA anthrax vaccine program has been supported by funding from the National Institute of Allergy and Infectious Disease, National Institutes of Health, and the Biomedical Advanced Research and Development Authority.

About PharmAthene

PharmAthene is a leading biodefense company engaged in the development and commercialization of next generation medical countermeasures against biological and chemical threats. PharmAthene's current biodefense portfolio includes the following product candidates:

• SparVax^® - a next generation recombinant protective antigen (rPA) anthrax vaccine
• rBChE bioscavenger - a medical countermeasure for nerve agent poisoning by organophosphorous compounds, including nerve gases and pesticides
• Valortim^® - a fully human monoclonal antibody for the prevention and treatment of anthrax infection

In addition, in May 2013, the Delaware Supreme Court issued its ruling on the appeal in our litigation with SIGA Technologies, affirming the Delaware Court of Chancery's finding that SIGA was liable for breach of contract, reversing its finding of promissory estoppel, and remanding the case back to the Delaware Court of Chancery to reconsider the appropriate remedy and award of attorney's fees and expert witness costs in light of the Delaware Supreme Court's opinion. For more information about PharmAthene, please visit www.PharmAthene.com.

Forward-Looking Statement Disclaimer

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 "will"; "potential"; "believe"; "anticipate"; "look forward"; "intend"; "plan"; "expect"; "estimate"; "could"; "may"; "should"; or similar statements are forward-looking statements. Such statements include, but are not limited to those referring to the outcome of the SIGA litigation and our ability to deploy our resources. PharmAthene disclaims any intent or obligation to update these forward-looking statements. Risks and uncertainties include, among others, risks associated with the reliability of the results of the studies relating to human safety and possible adverse effects resulting from 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; awards 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 annual reports on Form 10-K and quarterly reports on Form 10-Q under the caption "Risk Factors" and in its other reports filed with the U.S. Securities and Exchange Commission. In particular, there is significant uncertainty regarding the level and timing of sales of Arestvyr and whether and when it will be approved by the U.S. FDA and corresponding health agencies around the world. PharmAthene cannot predict with certainty if or when SIGA will begin recognizing profit on the sale thereof and there can be no assurance that any profits received by SIGA will be significant. In its May 2013 decision, the Delaware Supreme Court reversed the remedy ordered by the Delaware Court of Chancery and remanded the issue of a remedy back to the trial court for reconsideration in light of the Delaware Supreme Court's opinion. As a result, there can be no assurance that the Delaware Chancery Court will issue a remedy that provides PharmAthene with a financial interest in Arestvyr and related products or any remedy. In addition, significant additional research work, non-clinical animal studies, clinical trials, and manufacturing development work remains to be done with respect to PharmAthene's product candidates. At this point, there can be no assurance that any of these product candidates 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 its website under the investor relations tab at www.pharmathene.com.

SOURCE PharmAthene, Inc.