ST-246(R) to be Branded Arestvyr(TM)

ST-246(R) to be Branded Arestvyr(TM)

BARDA Payment Received

NEW YORK, Nov. 29, 2012 (GLOBE NEWSWIRE) -- SIGA Technologies, Inc.
(Nasdaq:SIGA), a company specializing in the development of pharmaceutical
agents to fight pathogens capable of use as bioweapons, today announced that
its smallpox antiviral, previously known as ST-246®, would be branded as
Arestvyr™ for all purposes, including commercial sales and seeking full
marketing approval of the antiviral as a smallpox treatment.

"We are pleased to announce use of the Arestvyr™ name for our proprietary
smallpox antiviral treatment," said Dr. Eric A. Rose, Chairman and Chief
Executive Officer of SIGA."ST-246 (Tecovirimat) is becoming increasingly
better known around the world as we work to deliver two million courses of our
treatment to the United States Government's Strategic National
Stockpile.Adopting the Arestvyr™ name is another step in our commercial-stage
transformation."

SIGA is also pleased to confirm that it has received payment of the $12.3
million milestone previously invoiced to the U.S. government under SIGA's
Strategic National Stockpile contract.

About SIGA Technologies, Inc.

Communities in the United States and around the world face a serious but unmet
need for drugs to protect against potentially catastrophic emerging viral
pathogens and biological weapons of mass destruction. We are a pharmaceutical
company specializing in the development and commercialization of
pharmaceutical solutions for some of the most lethal disease-causing pathogens
in the world – smallpox, Ebola, dengue, Lassa fever and other dangerous
viruses. Our business is to discover, develop, manufacture and successfully
commercialize drugs to prevent and treat these high-priority threats. Our
mission is to disarm dreaded viral diseases and create robust, modern
biodefense countermeasures. For more information about SIGA, please visit
SIGA's web site at www.siga.com.

The SIGA Technologies, Inc. logo is available at
http://www.globenewswire.com/newsroom/prs/?pkgid=4504

Forward-looking Statements

This press release contains certain "forward-looking statements" within the
meaning of the Private Securities Litigation Reform Act of 1995, as amended,
including statements relating to performance on SIGA's contract with the
Biomedical Advanced Research and Development Authority (BARDA) of the United
States Department of Health and Human Services and its efforts to seek
approval and licensing from the United States Food and Drug
Administration.Forward-looking statements are based on management's
estimates, assumptions and projections, and are subject to uncertainties, many
of which are beyond our control. Actual results may differ materially from
those anticipated in any forward-looking statement. Factors that may cause
such differences include (i) the risk that potential products that appear
promising to us or our collaborators cannot be shown to be efficacious or safe
in subsequent pre-clinical or clinical trials, (ii) the risk that we or our
collaborators will not obtain appropriate or necessary governmental approvals
to market these or other potential products, (iii) the risk that we may not be
able to obtain anticipated funding for our development projects or other
needed funding, (iv) the risk that we may not be able to secure funding from
anticipated or current government contracts and grants, (v) the risk that we
may not be able to secure or enforce sufficient legal rights in our products,
including patent protection, (vi) the risk that any challenge to our patent
and other property rights, if adversely determined, could affect our business
and, even if determined favorably, could be costly, (vii) the risk that the
adverse judgment obtained by PharmAthene, Inc., if upheld, could adversely
affect our ability to enjoy the benefits of commercial sales of Arestvyr™,
(viii) the risk that regulatory requirements applicable to our products may
result in the need for further or additional testing or documentation that
will delay or prevent seeking or obtaining needed approvals to market these
products, (ix) the risk that our BARDA contract is modified or cancelled at
the request or requirement of the U.S. government, (x) the risk that the
volatile and competitive nature of the biotechnology industry may hamper our
efforts to develop or market our products, (xii) the risk that changes in
domestic and foreign economic and market conditions may adversely affect our
ability to advance our research or products, and (xiii) the effect of any
change to federal, state or foreign regulation, including drug regulation and
international trade regulation, on our business. More detailed information
about our company and risk factors that may affect the realization of
forward-looking statements, including the forward-looking statements set forth
here, is set forth in our filings with the Securities and Exchange Commission
(the SEC), including our Annual Report on Form 10-K for the fiscal year ended
December 31, 2011, and in other documents that we have filed with the SEC. We
urge investors and security holders to read those documents free of charge at
the SEC's Web site at http://www.sec.gov. Interested parties may also obtain
those documents free of charge directly from us. Forward-looking statements
speak only as of the date they are made, and except for our ongoing
obligations under the federal securities laws, we undertake no obligation to
update publicly any forward-looking statement whether as a result of new
information, future events or otherwise.

CONTACT: KCSA Strategic Communications
         Todd Fromer / Rob Fink
         212-896-1215 / 1206
         Tfromer@kcsa.com / rfink@kcsa.com

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