UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                           --------------------------

                                    FORM 8-K

                                 CURRENT REPORT
                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

        Date of report (Date of earliest event reported): October 8, 2003

                                   ----------

                             SIGA Technologies, Inc.
               (Exact Name of Registrant as Specified in Charter)

            Delaware                    0-23047                 13-3864870
(State or other Jurisdiction of    (Commission File          (I.R.S. Employer
 Incorporation or Organization)         Number)           Identification Number)

                         420 Lexington Avenue, Suite 601
                            New York, New York 10170
                    (Address of Principal Executive Offices)
                                   (Zip Code)

                                 (212) 672-9100
              (Registrant's telephone number, including area code)




ITEM 5. Other Events and Required FD Disclosure.

            On October 8, 2003, MacAndrews & Forbes Holdings Inc., a Delaware
corporation ("MacAndrews & Forbes"), and its affiliate, TransTech Pharma, Inc.,
a privately held drug discovery company ("TransTech Pharma"), committed to
invest $9,000,000 in SIGA Technologies, Inc., a Delaware corporation ("SIGA"),
in exchange for an aggregate of 6,250,000 shares of common stock, par value
$.0001 per share, of SIGA ("Common Stock"), and warrants to purchase up to an
aggregate of 3,125,000 shares of Common Stock, upon exercise of an option
granted pursuant to a purchase agreement dated August 13, 2003, between SIGA and
MacAndrews & Forbes (the "Purchase Agreement"). Immediately prior to the
exercise of such option, MacAndrews & Forbes assigned the right to invest up to
$5,000,000 in SIGA to TransTech Pharma pursuant to a letter agreement dated
October 8, 2003, among SIGA, MacAndrews & Forbes and TransTech Pharma (the
"Letter Agreement").

            In accordance with and subject to the terms and conditions of the
Purchase Agreement and the Letter Agreement, (i) MacAndrews & Forbes will
immediately invest $2,159,405 in SIGA in exchange for 1,499,587 shares of Common
Stock at a price of $1.44 per share and warrants to purchase up to an additional
749,794 shares of Common Stock at an exercise price of $2.00 per share; and (ii)
following approval of SIGA's stockholders, as required under the rules of the
Nasdaq SmallCap Market, MacAndrews & Forbes will invest $1,840,595 in SIGA in
exchange for 1,278,191 shares of Common Stock and warrants to purchase up to an
additional 639,095 shares of Common Stock on the same terms, and TransTech
Pharma will invest $5,000,000 in SIGA in exchange for 3,472,222 shares of Common
Stock and warrants to purchase up to an additional 1,736,111 shares of Common
Stock on the same terms.

            SIGA anticipates using funds from the investments described herein
for research and development, the pursuit of growth opportunities and general
corporate purposes.

            The description of the transactions set forth herein does not
purport to be complete and is qualified in its entirety by reference to the full
text of each of the exhibits filed herewith and incorporated by this reference.

ITEM 7. Financial Statements and Exhibits

(c) Exhibits

      Exhibit No.       Description
      -----------       -----------

      10(ggg)           Letter Agreement dated October 8, 2003 among SIGA
                        Technologies, Inc., MacAndrews & Forbes Holdings Inc.
                        and TransTech Pharma, Inc.

      99.1              Press Release dated October 8, 2003.


                                     - 2 -


                                   SIGNATURES

            Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                        SIGA TECHNOLOGIES, INC.


                                        By:  /s/ Thomas N. Konatich
                                             ----------------------
                                             Thomas N. Konatich
                                             Acting Chief Executive Officer and
                                             Chief Financial Officer

Date: October 9, 2003


                                     - 3 -


                                  EXHIBIT INDEX

Exhibit Number    Description
- --------------    -----------

      10(ggg)     Letter Agreement dated October 8, 2003 among SIGA
                  Technologies, Inc., MacAndrews & Forbes Holdings Inc. and
                  TransTech Pharma, Inc.

      99.1        Press Release dated October 8, 2003.

                                                                 Exhibit 10(ggg)

                        MacAndrews & Forbes Holdings Inc.
                               35 East 62nd Street
                            New York, New York 10021

                                                October 8, 2003

SIGA Technologies, Inc.
420 Lexington Avenue, Suite 601
New York, New York 10170
Attention:  Thomas N. Konatich

Dear Mr. Konatich:

            Reference is made to the Securities Purchase Agreement (the
"Purchase Agreement"), dated August 13, 2003, by and between SIGA Technologies,
Inc. (the "Company") and MacAndrews & Forbes Holdings Inc. ("M & F").
Capitalized terms used but not defined herein shall have the meanings set forth
in the Purchase Agreement.

            Pursuant to Section 10.5 of the Purchase Agreement, M & F hereby
assigns in part its right to purchase Shares and Warrants to a Permitted
Transferee (the "Assignee") as set forth on Schedule A hereto.

            The undersigned Assignee hereby agrees that it will be bound by all
provisions of the Purchase Agreement that are binding on the Purchaser
thereunder. Without limiting the foregoing, the Assignee hereby represents and
warrants to the Company that:

1.    Investment Representations and Warranties. The Assignee understands that
      the Securities have not been, and will not upon issuance be, registered
      under the Securities Act, and that the certificates evidencing the
      Securities shall bear a legend to that effect, unless prior to issuance,
      the Securities shall have been so registered.

2.    Acquisition for Own Account. The Assignee is acquiring the Securities for
      its own account for investment and not with a view toward distribution in
      a manner which would violate the Securities Act.

3.    Ability to Protect Its Own Interests and Bear Economic Risks;
      Understanding of Use of Proceeds. By reason of the business and financial
      experience of its management, the Assignee has the capacity to protect its
      own interests in connection with the transactions contemplated by the
      Purchase Agreement. The Assignee is able to bear the economic risk of an
      investment in the Securities, and has an adequate income independent of
      any income produced from an investment in the Securities and has
      sufficient net worth to sustain a loss of all of its



      investment in the Securities without economic hardship if such a loss
      should occur. The Assignee understands in all material respects the
      purposes for which the proceeds to the Company from the sale of the Shares
      and the Warrants will be used, as such purposes are set forth in Section
      7.8 of the Purchase Agreement.

4.    Accredited Investor. The Assignee is an "accredited investor" as that term
      is defined in Regulation D promulgated under the Securities Act.

5.    Access to Information. The Assignee has been furnished with the materials
      relating to the Company's business, operations, financial condition,
      assets, liabilities and other matters relevant to the Assignee's
      investment in the Securities, which have been requested by the Assignee.
      The Assignee has had adequate opportunity to ask questions of, and receive
      answers from, the Company's officers, employees, agents, accountants, and
      representatives concerning the Company's business, operations, financial
      condition, assets, liabilities, and all other matters relevant to its
      investment in the Securities.

            In connection with the assignment to the Assignee, Section 7.7(a) of
the Purchase Agreement is hereby amended by deleting it in its entirety and
substituting the following in lieu thereof:

            "(a) (i) At such time as MacAndrews & Forbes Holdings Inc. ("M & F")
      and TransTech Pharma, Inc. ("TTP") shall have invested an aggregate of
      $5,000,000 or more in Shares and, with respect to the M & F Representative
      (as defined below), for so long as M & F, together with its Affiliates
      (other than TTP), beneficially owns at least 1,700,000 Shares (as
      appropriately adjusted for any stock split, combination, reorganization,
      recapitalization, reclassification, stock dividend, stock distribution or
      similar event), and, with respect to the TTP Representative (as defined
      below), for so long as TTP, together with its Affiliates (other than M &
      F, its officers or Affiliates), beneficially owns at least 1,700,000
      Shares (as appropriately adjusted for any stock split, combination,
      reorganization, recapitalization, reclassification, stock dividend, stock
      distribution or similar event), the Company shall use its reasonable best
      efforts to appoint to its Board of Directors one individual designated by
      M & F (the "M & F Representative") and one individual designated by TTP
      (the "TTP Representative" and together with the M & F Representative, the
      "Purchaser Representatives"). Prior to such time, the Company shall enter
      into indemnification agreements with each of the Purchaser Representatives
      on terms no less favorable to the Purchaser Representatives than the terms
      of the indemnification agreements of the existing members of the Board of
      Directors.

            (ii) The initial Purchaser Representatives shall be those Persons
      who are designated by M & F or TTP, as the case may be, following the
      fulfillment of the conditions set forth in Section 7.7(a)(i) hereof to
      serve until their successors are duly elected; and thereafter the
      Purchaser


                                       2


      Representatives shall be elected at the same time as other members of the
      Company's Board of Directors. If for any reason the M & F Representative
      or the TTP Representative shall resign or otherwise be removed from the
      Company's Board of Directors, then the Company shall use its reasonable
      best efforts to appoint, as his or her replacement, the individual
      designated by M & F or TTP, as the case may be."

            Further, Section 7.7(d) of the Purchase Agreement is hereby amended
by deleting the phrase "M & F Representatives" and inserting in lieu thereof the
phrase "Purchaser Representatives."

            As modified hereby, the Purchase Agreement and its terms and
provisions are hereby ratified and confirmed for all purposes and in all
respects.

            The internal laws, and not the laws of conflicts (other than Section
5-1401 of the General Obligations Law of the State of New York), of New York
shall govern the enforceability and validity of this letter agreement, the
construction of its terms and the interpretation of the rights and duties of the
parties. Any suit, action or proceeding seeking to enforce any provision of, or
based on any matter arising out of or in connection with, this letter agreement
or the transactions contemplated hereby may be brought in any federal or state
court located in the County and State of New York, and each of the parties
hereby consents to the jurisdiction of such courts (and of the appropriate
appellate courts therefrom) in any such suit, action or proceeding and
irrevocably waives, to the fullest extent permitted by law, any objection which
it may now or hereafter have to the laying of the venue of any such suit, action
or proceeding in any such court or that any such suit, action or proceeding
which is brought in any such court has been brought in an inconvenient forum.
Process in any such suit, action or proceeding may be served on either party
anywhere in the world, whether within or without the jurisdiction of any such
court.

            Nothing expressed or referred to in this letter agreement will be
construed to give any person other than the parties to this letter agreement and
the Company any legal or equitable right, remedy, or claim under or with respect
to this letter agreement or any provision of this letter agreement. This letter
agreement and all of its provisions and conditions are for the sole and
exclusive benefit of the parties to this letter agreement and the Company.

            No change or modification of this letter agreement shall be valid
unless the same is in writing and signed by the parties hereto. No waiver of any
provision of this letter agreement shall be valid unless in writing and signed
by the party waiving its rights. The failure of any party at any time to insist
upon, or any delay by either party at any time to insist upon, strict
performance of any condition, promise, agreement or understanding set forth
herein shall not be construed as a waiver or relinquishment of the right to
insist upon strict performance of the same condition, promise, agreement or
understanding at a future time.

                                    * * * * *


                                       3


            Please indicate your agreement with the foregoing by executing and
returning the enclosed copy of this letter agreement.

                                        Sincerely,

                                        MACANDREWS & FORBES HOLDINGS INC.


                                        By: /s/ Howard Gittis
                                            -----------------
                                            Name: Howard Gittis
                                            Title: Vice Chairman

                 [SIGNATURE PAGE TO ASSIGNMENT LETTER AGREEMENT]




ACCEPTED AND AGREED:

TransTech Pharma, Inc.


By: /s/ Adnan Mjalli
    ----------------
Name: Adnan Mjalli
Title: President and CEO

                 [SIGNATURE PAGE TO ASSIGNMENT LETTER AGREEMENT]




ACCEPTED AND AGREED:

SIGA Technologies, Inc.


By: /s/ Thomas N. Konatich
    ----------------------
Name: Thomas N. Konatich
Title: Acting Chief Executive Officer

                 [SIGNATURE PAGE TO ASSIGNMENT LETTER AGREEMENT]




                                                                      Schedule A

                             Assignment to Assignee

- ------------------------------------------------------------------------------------------ Name of Assignee Maximum Number of Tranche B Maximum aggregate purchase price Shares which Assignee is which Assignee is to pay for assigned right to purchase Tranche B Shares at the Per Share Purchase Price (Tranche B Warrants to be issued for no additional consideration) - ------------------------------------------------------------------------------------------ TransTech Pharma, Inc. 3,472,222 $4,999,999.68 - ------------------------------------------------------------------------------------------
                                                                    EXHIBIT 99.1

SiGA [LOGO]

Contact:                                                       Investor Contact:
Thomas N. Konatich                                                   Dianne Will
SIGA Technologies, Inc.                               Willstar Consultants, Inc.
CFO & Acting CEO                                                  (518) 398-6222
(212) 672-9100                                                dwill@willstar.net

                           SIGA Technologies Announces
                    MacAndrews & Forbes and TransTech Pharma
                       Commit to Invest $9,000,000 in SIGA
                     Pursuant to Previously Announced Option

NEW YORK, October 8, 2003 -- SIGA Technologies, Inc. (NASDAQ: SIGA and
FRANKFURT: SGW 919 473), a biopharmaceuticals company developing products for
the prevention and treatment of serious infectious diseases, including products
for use against biological warfare agents such as smallpox, announced today that
MacAndrews & Forbes Holdings Inc., a corporation wholly-owned by Ronald O.
Perelman, and TransTech Pharma, Inc., a privately held drug discovery company,
have committed to invest $9,000,000 in SIGA pursuant to the terms of an option
granted in August 2003.

As previously announced, on August 13, 2003, MacAndrews & Forbes invested
$1,000,000 in SIGA in exchange for 694,444 shares of SIGA common stock at a
price of $1.44 per share and warrants to purchase an additional 347,222 shares
of SIGA common stock at an exercise price of $2.00 per share. At that time,
MacAndrews & Forbes was also granted an option, exercisable through October 13,
2003, to make additional investments in SIGA of up to $9,000,000 in exchange for
up to an additional 6,250,000 shares of SIGA common stock and warrants to
purchase up to an additional 3,125,000 shares of SIGA common stock on the same
terms. MacAndrews & Forbes, immediately prior to the exercise of the option,
assigned the right to invest up to $5,000,000 to its affiliate, TransTech
Pharma. SIGA and TransTech Pharma are parties to a drug discovery collaboration
agreement.

"We are very pleased with this investment in SIGA from MacAndrews & Forbes and
TransTech. Our ongoing collaboration with TransTech has made excellent progress
in developing anti-infective small molecule drug candidates directed against our
in-house targets. TransTech's investment in SIGA will bring our two companies
closer together, and better enable us to meet our common goals," said Thomas N.
Konatich, Acting Chief Executive Officer and Chief Financial Officer of SIGA.

Dr. Adnan Mjalli, President and Chief Executive Officer of TransTech Pharma
said, " We at TransTech highly value SIGA's proprietary anti-infective
technology platform. This investment




will provide resources to enable SIGA to move forward aggressively with the
development of the drug candidates resulting from our research collaboration, as
well as its own programs."

In accordance with the rules of the Nasdaq SmallCap Market, a portion of this
investment will require the approval of SIGA's stockholders. MacAndrews & Forbes
will immediately invest $2,159,405 in SIGA in exchange for 1,499,587 shares of
SIGA common stock at a price of $1.44 per share and warrants to purchase up to
an additional 749,794 shares of SIGA common stock at an exercise price of $2.00
per share. Following stockholder approval, MacAndrews & Forbes will invest
$1,840,595 in SIGA in exchange for 1,278,191 shares of SIGA common stock and
warrants to purchase up to an additional 639,095 shares of SIGA common stock on
the same terms; and TransTech Pharma will invest $5,000,000 in SIGA in exchange
for 3,472,222 shares of SIGA common stock and warrants to purchase up to an
additional 1,736,111 shares of SIGA common stock on the same terms.

SIGA anticipates using funds from these investments for research and
development, the pursuit of growth opportunities and general corporate purposes.
That portion of the investment which requires stockholder approval is expected
to close by January 31, 2004; however, no assurances can be given as to the
timing of stockholder approval or that stockholder approval will be obtained.

In accordance with the August 13, 2003 purchase agreement pursuant to which the
option was granted and the assignment agreement between MacAndrews & Forbes and
TransTech Pharma, SIGA agreed to use its reasonable best efforts to appoint to
its board of directors one individual designated by MacAndrews & Forbes and one
individual designated by TransTech Pharma at such time as MacAndrews & Forbes
and TransTech Pharma shall have invested an aggregate of at least $5,000,000 in
SIGA.

The members of SIGA's board of directors who are not affiliated with MacAndrews
& Forbes separately considered and approved the purchase agreement and the
transactions contemplated thereby.

About SIGA Technologies, Inc.

SIGA Technologies is applying bacterial genomics 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 has
the potential of becoming a significant force in the discovery of vaccine and
pharmaceutical agents to fight emerging pathogens. SIGA's product development
programs emphasize the increasingly serious problem of drug resistant bacteria
and emerging pathogens. SIGA's vaccine and drug platforms are based on its
pioneering research into the structure, function and processing of bacterial
surface proteins. SIGA is leveraging these platforms through multiple strategic
partners, including Wyeth-Ayerst Laboratories (the pharmaceutical division of
American Home Products) and the National Institutes of Health. For more
information about SIGA, please visit SIGA's Web site at www.siga.com.

About TransTech Pharma, Inc.

TransTech Pharma is a privately held drug discovery and development company
employing approximately 70 people. TransTech Pharma's high-throughput drug
discovery platform, TTP




Translational Technology(R), translates the wealth of information from genomics
and proteomics into novel and effective small molecules as therapeutics. In
addition to its collaboration with SIGA, TransTech Pharma has multi-year,
multi-target drug discovery collaborations with Novo Nordisk A/S and Cephalon,
Inc., both of which have an equity position in TransTech Pharma. In
addition,TransTech Pharma is committed to the continued development of its own
pre-clinical and clinical pipeline of small molecule drug candidates. For more
information about TransTech Pharma, please visit TransTech Pharma's Web site at
www.ttpharma.com.

This news release contains certain "forward-looking statements" within the
meaning of the Private Securities Litigation Reform Act of 1995, including
statements regarding the efficacy and intended use of SIGA's technologies under
development and the likelihood that the proposed investment will be completed.
Forward-looking statements are based on management's estimates, assumptions and
projections, and are subject to uncertainties, many of which are beyond the
control of SIGA. Actual results may differ materially from those anticipated in
any forward-looking statement. Factors which may cause such differences include
the risks: that potential products that appeared promising to SIGA or its
collaborators in early research or clinical trials do not demonstrate efficacy
or safety in subsequent pre-clinical or clinical trials and that SIGA or its
collaborators will not obtain appropriate or necessary government approvals to
market products tested in such trials; and that the completion of due diligence,
the timely receipt of necessary approvals including shareholder approval and the
satisfaction of all closing conditions may not be accomplished.

Investors and security holders are urged to read the proxy statement that will
be sent to SIGA shareholders regarding the proposed issuance of securities, when
such proxy statement becomes available, because such proxy statement will
contain important information. The proxy statement will be filed with the U.S.
Securities and Exchange Commission by SIGA. Investors and security holders may
obtain a free copy of the proxy statement, when such proxy statement is
available, and any other documents filed by SIGA with the Commission at the
Commission's Web site at www.sec.gov. Such proxy statement and these other
documents may also be obtained, when available, free of charge from SIGA. SIGA's
shareholders should read such proxy statement carefully before making a decision
concerning the proposed issuance of securities.

SIGA and its respective directors, executive officers and certain other of its
respective employees may be soliciting proxies from its shareholders in favor of
the approval of the proposed issuance of securities. Information regarding the
directors and executive officers who may, under rules promulgated by the
Commission, be deemed to be participants in the solicitation of SIGA
shareholders in connection with the proposed issuance of securities is set forth
in SIGA's proxy statement for its 2002 annual meeting, and additional
information will be set forth in the definitive proxy statement referred to
above when it is filed with the Commission.

More detailed information about SIGA and the factors discussed above is set
forth in SIGA's filings with the Commission, including SIGA's Annual Report on
Form 10-K for the fiscal year ended December 31, 2002, as amended, and in other
documents that SIGA has filed with the Commission. Investors and security
holders are urged to read those documents free of charge at the Commission's Web
site at www.sec.gov. Those documents may also be obtained free of charge from
SIGA. SIGA does not undertake to publicly update or revise its forward-looking
statements as a result of new information, future events or otherwise.