Exhibit 10.1

SUBSCRIPTION AGREEMENT

SIGA Technologies, Inc.
420
Lexington Avenue, Suite 408
New York, NY 10170

Gentlemen:

     The undersigned (the
“Investor”) hereby confirms its agreement
with SIGA Technologies, Inc., a Delaware corporation (the “Company”), as follows:

     1. This Subscription Agreement, including
the Terms and Conditions for Purchase of Shares attached
hereto as Annex I (collectively, this “Agreement”) is made as of the date set forth below between the
Company and the Investor.

     2. The Company has authorized the sale and issuance to
certain investors of up to an aggregate of 2,725,339 shares (the “Shares”) of its Common Stock, par value $0.0001 per
share (the “Common Stock”), subject to
adjustment by the Company’s Board of Directors or a committee thereof, for a
purchase price of $7.35 per share (the “Purchase
Price”).

     3. The offering and sale of the Shares (the “Offering”) are being made pursuant to (a) an
effective Registration Statement on Form S-3 (the “Registration Statement”) filed by the Company with the
Securities and Exchange Commission (the “Commission”), including the Prospectus contained therein (the
“Base Prospectus”), (b) if applicable,
certain “free writing prospectuses” (as that term is defined in Rule 405 under
the Securities Act of 1933, as amended (the “Act”)), that have been or will be filed with the Commission
and delivered to the Investor on or prior to the date hereof (the “Issuer Free Writing Prospectus”), containing
certain supplemental information regarding the Shares, the terms of the Offering
and the Company and (c) a Prospectus Supplement (the “Prospectus Supplement” and, together with the Base Prospectus,
the “Prospectus”) containing certain supplemental
information regarding the Shares and terms of the Offering that has been or will
be filed with the Commission and delivered to the Investor (or made available to
the Investor by the filing by the Company of an electronic version thereof with
the Commission).

     4. The Company and the Investor agree that the Investor
will purchase from the Company and the Company will issue and sell to the
Investor the Shares of Common Stock set forth below for the aggregate purchase
price set forth below. The Shares shall be purchased pursuant to the Terms and
Conditions for Purchase of Shares attached hereto as Annex I and incorporated herein by this reference as if fully
set forth herein. The Investor acknowledges that the Offering is not being
underwritten by the placement agent (the “Placement
Agent”) named in the Prospectus Supplement and that there is no
minimum offering amount.




     5.
The manner of settlement of the Shares purchased by the Investor shall be
delivery by crediting the account of the Investor's prime broker (as specified
by such Investor on Exhibit A annexed hereto) with the Depository Trust
Company (“DTC”) through its Deposit/Withdrawal At Custodian
("DWAC") system, whereby Investor's prime broker shall initiate a DWAC
transaction on the Closing Date using its DTC participant identification number,
and released by American Stock Transfer & Trust Company, the Company’s
transfer agent (the “Transfer Agent”), at the Company's direction. NO
LATER THAN ONE (1) BUSINESS DAY AFTER THE EXECUTION OF THIS AGREEMENT BY THE
INVESTOR AND THE COMPANY, THE INVESTOR SHALL:

	     	(I)	     	
      DIRECT THE BROKER-DEALER AT
      WHICH THE ACCOUNT OR ACCOUNTS TO BE CREDITED WITH THE SHARES ARE
      MAINTAINED TO SET UP A DWAC INSTRUCTING THE TRANSFER AGENT TO CREDIT SUCH
      ACCOUNT OR ACCOUNTS WITH THE SHARES, AND

		 
		(II)		
      REMIT BY WIRE TRANSFER THE
      AMOUNT OF FUNDS EQUAL TO THE AGGREGATE PURCHASE PRICE FOR THE SHARES BEING
      PURCHASED BY THE INVESTOR TO THE FOLLOWING ACCOUNT:

		 


	                       	Citibank,
      N.A.
	 	666 Fifth
      Avenue
		New York, NY
      10103
		ABA #
      021000089
		Account Name:
      Kramer Levin Naftalis & Frankel LLP
	 	                          Attorney
      Escrow Account
		Account Number:
      37317968
		Reference: SIGA
      TECHNOLOGIES, INC.
	 	Attention: Rose DiGiorgio
		Tel: (212)
      559-6299



IT IS THE INVESTOR’S
RESPONSIBILITY TO (A) MAKE THE NECESSARY WIRE
TRANSFER OR CONFIRM THE PROPER ACCOUNT BALANCE IN A TIMELY MANNER AND (B) ARRANGE FOR SETTLEMENT BY WAY OF DWAC IN A
TIMELY MANNER. IF THE INVESTOR DOES NOT DELIVER
THE AGGREGATE PURCHASE PRICE FOR THE SHARES OR
DOES NOT MAKE PROPER ARRANGEMENTS FOR SETTLEMENT IN A TIMELY MANNER, THE SHARES MAY NOT BE DELIVERED AT CLOSING TO
THE INVESTOR OR THE INVESTOR MAY BE EXCLUDED FROM
THE CLOSING ALTOGETHER.

     6. The Investor represents that,
except as set forth below, (a) it has had no position, office or other material
relationship within the past three years with the Company or persons known to it
to be affiliates of the Company, (b) it is not a FINRA member or an Associated
Person (as such term is defined under the NASD Membership and Registration Rules
Section 1011) as of the Closing, and (c) neither the Investor nor any group of
Investors (as identified in a public filing made with the Commission) of which
the Investor is a part in connection with the Offering of the Shares, acquired,
or obtained the right to acquire, 20% or more of the Common Stock (or securities
convertible into or exercisable for Common Stock) or the voting power of the
Company on a post-transaction basis. Exceptions:

	 
	(If no exceptions, write “none.” If left blank, response will be
      deemed to be “none.”) 



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     7. The
Investor represents that it has received (or otherwise had made available to it
by the filing by the Company of an electronic version thereof with the
Commission) the Base Prospectus which is a part of the Company’s Registration
Statement, the documents incorporated by reference therein and any free writing prospectus (collectively, the
“Disclosure Package”), prior to or in connection with the receipt of this Agreement. The
Investor acknowledges that, prior to the delivery of this Agreement to the
Company, the Investor will receive certain additional information regarding the
Offering, including pricing information (the “Offering Information”). Such
information may be provided to the Investor by any means permitted under the
Act, including the Prospectus Supplement, a free writing prospectus and oral
communications.

     8. No offer by the Investor to buy Shares will be accepted and no
part of the Purchase Price will be delivered to
the Company until the Investor has received the Offering Information and the
Company has accepted such offer by countersigning a copy of this Agreement, and
any such offer may be withdrawn or revoked, without obligation or commitment of
any kind, at any time prior to the Company (or Placement Agent on behalf of the
Company) sending (orally, in writing or by electronic mail) notice of its
acceptance of such offer. An indication of interest will involve no obligation
or commitment of any kind until the Investor has been delivered the Offering
Information and this Agreement is accepted and countersigned by or on behalf of
the Company.

     9. The Company acknowledges that the
only material, non-public information relating to the Company it has provided to
the Investor in connection with the Offering prior to the date hereof is the
existence of the Offering.

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	Number of
      Shares: 	 
	Purchase Price
      Per Share: $ 	 
	Aggregate
      Purchase Price: $ 	 



     Please confirm that the foregoing correctly sets forth the agreement
between us by signing in the space provided below for that
purpose.

		Dated
      as of: December __, 2009 
		 
		 
		INVESTOR 	 
		By: 	 
		Print Name: 	 
		Title: 	 
		Address: 	 
	 	 	 



	Agreed
      and Accepted 
	this
      __ day of December, 2009: 
	 
	 
	SIGA TECHNOLOGIES, INC.  
	 
	 
	By: 	 
	Title:  



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ANNEX I

TERMS AND CONDITIONS FOR PURCHASE OF
SHARES

     1.
Authorization and Sale of the Shares. Subject to the terms and
conditions of this Agreement, the Company has authorized the sale of the
Shares.

     2. Agreement to
Sell and Purchase the Shares; Placement
Agent.

          2.1
At the Closing (as defined in Section 3.1), the Company will sell to the
Investor, and the Investor will purchase from the Company, upon the terms and
conditions set forth herein, the number of Shares set forth on the last page of
the Agreement to which these Terms and Conditions for Purchase of Shares are
attached as Annex I (the “Signature Page”) for the aggregate
purchase price therefor set forth on the Signature Page.

          2.2
The Company proposes to enter into substantially this same form of Subscription
Agreement with certain other investors (the “Other Investors”) and
expects to complete sales of Shares to them. The Investor and the Other
Investors are hereinafter sometimes collectively referred to as the
“Investors,” and this Agreement and the Subscription Agreements executed
by the Other Investors are hereinafter sometimes collectively referred to as the
“Agreements.”

          2.3
Investor acknowledges that the Company has agreed to pay RBC Capital Markets
Corporation (the “Placement Agent”) a fee (the “Placement Fee”) in
respect of the sale of Shares to the Investor.

          2.4
The Company has entered into a Placement Agent Agreement, dated December 9,
2009 (the “Placement Agreement”), with the Placement Agent that contains
certain representations, warranties, covenants and agreements of the Company that may be relied upon by
the Investor, which shall be a third party beneficiary thereof.

     3. Closings and Delivery of
the Shares and Funds.

          3.1
Closing. The completion of the purchase and sale of the
Shares (the “Closing”) shall occur at a place and time (the “Closing
Date”) to be specified by the Company and the Placement Agent, and of which
the Investors will be notified in advance by the Placement Agent, in accordance
with Rule 15c6-1 promulgated under the Securities Exchange Act of 1934, as
amended (the “Exchange Act”). At the Closing, (a) the Company shall cause
the Transfer Agent to deliver to the Investor the number of Shares set forth on
the Signature Page registered in the name of the Investor or, if so indicated on
the Investor Questionnaire attached hereto as Exhibit A, in the name of a
nominee designated by the Investor and (b) the aggregate purchase price for the
Shares being purchased by the Investor will be delivered by or on behalf of the
Investor to the Company.

          3.2 Conditions to the Obligations of the
Parties.

               (a)
Conditions to the Company’s Obligations. The Company’s
obligation to issue and sell the Shares to the Investor shall be subject to: (i)
the receipt by the Company of the purchase price for the Shares being purchased
hereunder as set forth on the Signature Page and (ii) the accuracy of the
representations and warranties made by the Investor and the fulfillment of those
undertakings of the Investor to be fulfilled prior to the Closing
Date.

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               (b)
Conditions to the Investor’s Obligations. The Investor’s
obligation to purchase the Shares will be subject to the accuracy of the
representations and warranties made by the Company and the fulfillment of those
undertakings of the Company to be fulfilled prior to the Closing Date, including
without limitation, those contained in the Placement Agreement, and to the
condition that the Placement Agent shall not have: (i) terminated the Placement
Agreement pursuant to the terms thereof or (ii) determined that the conditions
to the closing in the Placement Agreement have not been satisfied. The
Investor’s obligations are expressly not conditioned on the purchase by any or
all of the Other Investors of the Shares that they have agreed to purchase from
the Company. The Investor understands and agrees that, in the event that the
Placement Agent in its sole discretion determines that the conditions to closing
in the Placement Agreement have not been satisfied or if the Placement Agent
Agreement may be terminated for any other reason permitted by such Agreement,
then the Placement Agent may, but shall not be obligated to, terminate such
Agreement, which shall have the effect of terminating this Subscription
Agreement pursuant to Section 14 below.

          3.3
Delivery of Funds. No later than one (1) business day after the
execution of this Agreement by the
Investor and the Company, the Investor shall remit by wire transfer the
amount of funds equal to the aggregate purchase price for the Shares being
purchased by the Investor to the following:

	                       	Citibank,
      N.A. 
		666 Fifth
      Avenue 
		New York, NY
      10103 
		ABA #
      021000089 
		Account Name:
      Kramer Levin Naftalis & Frankel LLP 
		                          Attorney
      Escrow Account 
		Account Number:
      37317968 
		Reference: SIGA
      TECHNOLOGIES, INC. 
		Attention: Rose DiGiorgio 
		Tel: (212)
      559-6299 



               Such
funds shall be held in escrow until the Closing and delivered by the Escrow
Agent on behalf of the Investors to the Company upon the satisfaction, in the
sole judgment of the Placement Agent, of the conditions set forth in Section
3.2(b) hereof. The Placement Agent shall have no rights in or to any of the
escrowed funds, unless the Placement Agent and the Escrow Agent are notified in
writing by the Company in connection with the Closing that a portion of the
escrowed funds shall be applied to the Placement Fee. The Company agrees to
indemnify and hold the Escrow Agent harmless from and against any and all
losses, costs, damages, expenses and claims (including, without limitation,
court costs and reasonable attorneys fees) (“Losses”) arising under this
Section 3.3 or otherwise with respect to the funds held in escrow
pursuant hereto or arising under the Escrow Agreement, unless it is finally,
judicially determined that such Losses resulted directly from the willful
misconduct or gross negligence of the Escrow Agent. Anything in this Agreement
to the contrary notwithstanding, in no event shall the Escrow Agent be liable
for any special, indirect or consequential loss or damage of any kind whatsoever
(including but not limited to lost profits), even if the Escrow Agent has been
advised of the likelihood of such loss or damage and regardless of the form of
action.

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          3.4
Delivery of Shares. No later than one (1) business day after the
execution of this Agreement by the
Investor and the Company, the Investor shall direct the broker-dealer at
which the account or accounts to be credited with the Shares being purchased by
such Investor are maintained, which broker/dealer shall be a DTC participant, to
set up a DWAC instructing American Stock Transfer & Trust Company, the
Company’s Transfer Agent, to credit such account or accounts with the Shares.
Such DWAC instruction shall indicate the settlement date for the deposit of the
Shares, which date shall be provided to the Investor by RBC. Simultaneously with
the delivery to the Company by the Escrow Agent of the funds held in escrow
pursuant to Section 3.3 above, the Company shall direct the Transfer
Agent to credit the Investor’s account or accounts with the Shares pursuant to
the information contained in the DWAC.

     4. Representations,
Warranties and Covenants of the Investor.

     The Investor acknowledges,
represents and warrants to, and agrees with, the Company and the Placement Agent
that:

          4.1
The Investor (a) is knowledgeable, sophisticated and experienced in making, and
is qualified to make decisions with respect to, investments in shares presenting
an investment decision like that involved in the purchase of the Shares,
including investments in securities issued by the Company and investments in
comparable companies, (b) has answered all questions on the Signature Page and
the Investor Questionnaire and the answers thereto are true and correct as of
the date hereof and will be true and correct as of the Closing Date and (c) in
connection with its decision to purchase the number of Shares set forth on the
Signature Page, has received and is relying only upon the Disclosure Package and
the documents incorporated by reference therein and the Offering
Information.

          4.2
(a) No action has been or will be taken in any jurisdiction outside the United
States by the Company or the Placement Agent that would permit an offering of
the Shares, or possession or distribution of offering materials in connection
with the issue of the Shares in any jurisdiction outside the United States where
action for that purpose is required, (b) if the Investor is outside the United
States, it will comply with all applicable laws and regulations in each foreign
jurisdiction in which it purchases, offers, sells or delivers Shares or has in
its possession or distributes any offering material, in all cases at its own
expense and (c) the Placement Agent is not authorized to make and has not made
any representation, disclosure or use of any information in connection with the
issue, placement, purchase and sale of the Shares, except as set forth or
incorporated by reference in the Base Prospectus or the Prospectus
Supplement.

          4.3
(a) The Investor has full right, power, authority and capacity to enter into
this Agreement and to consummate the transactions contemplated hereby and has
taken all necessary action to authorize the execution, delivery and performance
of this Agreement, and (b) this Agreement constitutes a valid and binding
obligation of the Investor enforceable against the Investor in accordance with
its terms, except as enforceability may be limited by applicable bankruptcy,
insolvency, reorganization, moratorium or similar laws affecting creditors’ and
contracting parties’ rights generally and except as enforceability may be
subject to general principles of equity (regardless of whether such
enforceability is considered in a proceeding in equity or at law) and except as
to the enforceability of any rights to indemnification or contribution that may
be violative of the public policy underlying any law, rule or regulation
(including any federal or state securities law, rule or regulation).

- 7
-




          4.4
The Investor understands that nothing in this Agreement, the Prospectus or any
other materials presented to the Investor in connection with the purchase and
sale of the Shares constitutes legal, tax or investment advice. The Investor has
consulted such legal, tax and investment advisors and made such investigation as
it, in its sole discretion, has deemed necessary or appropriate in connection
with its purchase of Shares.

          4.5
Since the date on which the Placement Agent first contacted the Investor about
the Offering, it has not disclosed any information regarding the Offering to any
third parties (other than its legal, accounting and other advisors) and has not
engaged in any transactions involving the securities of the Company (including,
without limitation, any Short Sales involving the Company’s securities). The
Investor covenants that it will not engage in any transactions in the securities
of the Company (including Short Sales) prior to the time that the transactions
contemplated by this Agreement are publicly disclosed. The Investor agrees that
it will not use any of the Shares acquired pursuant to this Agreement to cover
any short position in the Common Stock if doing so would be in violation of
applicable securities laws. For purposes hereof, “Short Sales” include,
without limitation, all “short sales” as defined in Rule 200 promulgated under
Regulation SHO under the Exchange Act, whether or not against the box, and all
types of direct and indirect stock pledges, forward sales contracts, options,
puts, calls, short sales, swaps, “put equivalent positions” (as defined in Rule
16a-1(h) under the Exchange Act) and similar arrangements (including on a total
return basis), and sales and other transactions through non-US broker dealers or
foreign regulated brokers.

     5. Survival of
Representations, Warranties and Agreements; Third Party
Beneficiary.
Notwithstanding any investigation made by any party to this Agreement
or by the Placement Agent, all covenants, agreements, representations and
warranties made by the Company and the Investor herein will survive the
execution of this Agreement, the delivery to the Investor of the Shares being
purchased and the payment therefor. The Placement Agent. shall be third party
beneficiaries with respect to the representations, warranties and agreements of
the Investor in Section 4 hereof.

     6. Notices. All notices,
requests, consents and other communications hereunder will be in writing, will
be mailed (a) if within the domestic United States by first-class registered or
certified airmail, or nationally recognized overnight express courier, postage
prepaid, or by facsimile or (b) if delivered from outside the United States, by
International Federal Express or facsimile, and (c) will be deemed given (i) if
delivered by first-class registered or certified mail domestic, three business
days after so mailed, (ii) if delivered by nationally recognized overnight
carrier, one business day after so mailed, (iii) if delivered by International
Federal Express, two business days after so mailed and (iv) if delivered by
facsimile, upon electric confirmation of receipt and will be delivered and
addressed as follows:

	                       	     (a) 	     	if to
      the Company, to: 
	 	 		  
		 	 	SIGA
      Technologies, Inc. 
				420 Lexington Avenue 
		 		Suite
      408 
				New York, NY 10170 
		 		Attention:
      Ayelet Dugary 
		 		Facsimile:
      (212) 697-3130 
				 
				with copies
      to: 
				 
	 			Kramer Levin Naftalis &
      Frankel LLP 
				1177 Avenue of the
      Americas 
				New York, NY
      10036 
				Attention: James Grayer,
      Esq. 
				Facsimile: (212)
      715-8000 
				 
		
           (b)
       if to the Investor, at its address on
      the Signature Page hereto, or at such other address or addresses as may
      have been furnished to the Company in
writing.



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     7. Changes. This Agreement
may not be modified or amended except pursuant to an instrument in writing
signed by the Company and the Investor.

     8. Headings. The headings of
the various sections of this Agreement have been inserted for convenience of
reference only and will not be deemed to be part of this Agreement.

     9. Severability. In case any
provision contained in this Agreement should be invalid, illegal or
unenforceable in any respect, the validity, legality and enforceability of the
remaining provisions contained herein will not in any way be affected or
impaired thereby.

     10. Governing Law. This
Agreement will be governed by, and construed in accordance with, the internal
laws of the State of New York, without giving effect to the principles of
conflicts of law that would require the application of the laws of any other
jurisdiction.

     11. Counterparts. This
Agreement may be executed in two or more counterparts, each of which will
constitute an original, but all of which, when taken together, will constitute
but one instrument, and will become effective when one or more counterparts have
been signed by each party hereto and delivered to the other parties. The Company
and the Investor acknowledge and agree that the Company shall deliver its
counterpart to the Investor along with the Prospectus Supplement (or the filing
by the Company of an electronic version thereof with the Commission).

     12. Confirmation of Sale. The
Investor acknowledges and agrees that such Investor’s receipt of the Company’s
signed counterpart to this Agreement, together with the Prospectus Supplement
(or the filing by the Company of an electronic version thereof with the
Commission), shall constitute written confirmation of the Company’s sale of
Shares to such Investor.

     13. Press Release. The
Company and the Investor agree that the Company shall issue a press release
announcing the Offering and disclosing all material information regarding the
Offering prior to the opening of the financial markets in New York City on the
business day immediately after the date hereof.

     14. Termination. In the event
that the Placement Agreement is terminated by the Placement Agent pursuant to
the terms thereof, this Agreement shall terminate without any further action on
the part of the parties hereto.

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EXHIBIT A

SIGA TECHNOLOGIES,
INC.

INVESTOR QUESTIONNAIRE

     Pursuant
to Section 3 of Annex I to the Agreement, please provide us with the following
information:

	1.	   	The exact name that
      your Shares are to be registered in. You may use a nominee name if
      appropriate:	      	 	  
	 		 	
	2.		The relationship
      between the Investor and the registered holder listed in response to item
      1 above:		 	
	 		 	
	3.		The mailing address of
      the registered holder listed in response to item 1 above:	 	 	 
	 		 	
	4.		The Social Security
      Number or Tax Identification Number of the registered holder listed in the
      response to item 1 above:		 	
	 		 	
	5.		Name of DTC Participant
      (broker-dealer at which the account or accounts to be credited with the
      Shares are maintained):	 	 	
	 		 	
	6.		DTC Participant
      Number:		 	
	 		 	
	7.		Name of Account at DTC
      Participant being credited with the Shares:		 	
	 		 	
	8.		Account Number at DTC
      Participant being credited with the Shares: