SIGA Technologies Inc.

SIGA TECHNOLOGIES REPORTS OPERATING RESULTS FOR THE THIRD QUARTER OF 2008

Monday 10 November 2008

New York, New York, November 10, 2008

company specializing in the development of pharmaceutical agents to fight biowarfare pathogens,

today announced its results of operations for the third quarter of 2008.

The Company recognized revenues from grants and contracts of $1.9 million for the quarter

ended September 30, 2008, an increase of approximately 16% compared to the same quarter of

the prior year. The increase was primarily the result of revenue recognized from its contract with

the NIH to support the development of ST-246. Operating loss for the quarter was $2.1 million

compared to a loss for the third quarter of 2007 of $1.6 million. The increase in operating loss

was the result of higher legal and accounting costs and research and development expenses.

For the nine months ended September 30, 2008, the Company reported revenue of $5.6 million,

an increase of approximately 13% as compared to the $4.9 million reported for the nine months

ended September 30, 2007. The increase in revenue was primarily the result of $2.3 million in

revenue recorded from the Company’s contract with the NIH in support of its lead product

programs. This was partially offset by a decline in revenue from its program with the United

States Air Force, which was completed in April 2008.

Operating loss for the nine-month period was $6.2 million, an increase of approximately 15%

from the prior-year period. Net loss per share for the nine-month periods ending September 30,

2008 and 2007 were $0.20 and $0.15, respectively. The increase in losses resulted from the

increase in operating costs previously noted.

Dr. Eric Rose, SIGA’s Chairman and CEO, commented, “During the recent quarter, we received

contracts totaling $75 million from the NIH to support our research and development efforts with

respect to ST-246. One contract, for $55 million, will support our research on additional

formulations and indications for ST-246. The other, $20 million contract will allow us to develop

further and more rapidly the processes needed to manufacture ST-246 on a commercial scale. In

addition, we continue to communicate with BARDA and continue fostering our relations in

Europe following the Scientific Advice Working Party meeting last quarter. These strong

relationships and recent contracts, coupled with our scientific gains, bring us closer to the

anticipated commercialization of ST-246. We have tremendous confidence that we are on the

right path to successfully bring ST-246 to market. Finally, our relationship with NIH extends

beyond our development of ST-246, as evidenced by the receipt of approximately $3.5 million for

our Lassa Fever program and nearly $1 million to advance our work with Dengue Fever.”

– SIGA Technologies, Inc. (NASDAQ: SIGA), a

About SIGA Technologies, Inc.

SIGA Technologies is applying viral and bacterial genomics and sophisticated computational

modeling in the design and development of novel products for the prevention and treatment of

serious infectious diseases, with an emphasis on products for biological warfare defense. SIGA

believes that it is a leader in the development of pharmaceutical agents to fight potential biowarfare

pathogens. SIGA has antiviral programs targeting smallpox and other Category A

pathogens, including arenaviruses (Lassa fever, Junin, Machupo, Guanarito, Sabia, and

lymphocytic choriomeningitis), dengue virus, and the filoviruses (Ebola and Marburg). For more

information about SIGA, please visit SIGA’s Web site at http://www.siga.com/.

Forward-looking Statements

This press release contains or implies certain “forward-looking statements” within the meaning of

the Private Securities Litigation Reform Act of 1995, as amended, including statements regarding

the efficacy of potential products, the timelines for bringing such products to market and the

continued development and possible eventual approval of such products. Forward-looking

statements are based on management’s estimates, assumptions and projections, and are subject to

uncertainties, many of which are beyond SIGA’s control. Actual results may differ materially

from those anticipated in any forward-looking statement. Factors that may cause such differences

include the risks that (a) potential products that appear promising to SIGA or its collaborators

cannot be shown to be efficacious or safe in subsequent pre-clinical or clinical trials, (b) SIGA or

its collaborators will not obtain appropriate or necessary governmental approvals to market these

or other potential products, (c) SIGA may not be able to obtain anticipated funding for its

development projects or other needed funding, (d) SIGA may not be able to secure funding from

anticipated government contracts and grants, (e) SIGA may not be able to secure or enforce

sufficient legal rights in its products, including sufficient patent protection for its products and

(f) regulatory approval for SIGA’s products may require further or additional testing that will

delay or prevent approval. More detailed information about SIGA and risk factors that may affect

the realization of forward-looking statements, including the forward-looking statements in this

press release, is set forth in SIGA’s filings with the Securities and Exchange Commission,

including SIGA’s Annual Report on Form 10-K for the fiscal year ended December 31, 2007, and

in other documents that SIGA has filed with the Commission. SIGA urges investors and security

holders to read those documents free of charge at the Commission’s Web site at

http://www.sec.gov. Interested parties may also obtain those documents free of charge from

SIGA. Forward-looking statements speak only as to the date they are made, and, except for any

obligation under the U.S. federal securities laws, SIGA undertakes no obligation to publicly

update any forward-looking statement as a result of new information, future events or otherwise.

Contact:

Todd Fromer / Marybeth Csaby / David Burke

KCSA Strategic Communications

212-896-1215 / 1236 / 1258

Tfromer@kcsa.com / mcsaby@kcsa.com / dburke@kcsa.com