Company to Host Conference Call on May 8, 2007 at 11:00 a.m. Eastern

New York, New York April 23, 2007 - SIGA Technologies, Inc. (NASDAQ: SIGA), a company specializing in the development of pharmaceutical agents to fight biowarfare pathogens, announced today that the company's senior management will discuss SIGA's results of operations for the first quarter during a conference call scheduled for Tuesday, May 8, 2007, at 11:00 a.m. Eastern.  The company's financial results for the first quarter are scheduled to be released earlier that day.

What: SIGA Technologies, Inc. Investor Update Call

When: Tuesday, May 8, 2007, 11:00 a.m. Eastern

Web cast address: http://www.streetevents.com, http://www.fulldisclosure.com

Dial-in Numbers:  (800) 573-4840 (domestic) or 617-224-4326 (international), pass code # 38759131

Contact:  Al Palombo, Cameron Associates, (212) 245-8800 Ext. 209, al@cameronassoc.com

If you are unable to participate, an audio replay of the call will be available beginning two hours after the call and will be available until 11:59 p.m. on May 15, 2007, by dialing (888) 286-8010 (domestic) or (617) 801-6888 (international) using confirmation pass code 19705911.

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.  In addition to smallpox, SIGA has antiviral programs targeting 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 www.siga.com.