<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>3
<FILENAME>ex99-1.txt
<DESCRIPTION>PRESS RELEASE
<TEXT>

EXHIBIT 99.1

SIGA Technologies Contact:                     Allergy Therapeutics Contact:
Thomas N. Konatich                             Iain G Ross
CFO & Acting CEO                               Chairman & CEO
(212) 672-9100                                 +44 (0) 1903-844720
tkonatich@siga.com                             iain.ross@allergytherapeutics.com

FOR IMMEDIATE RELEASE
March 11, 2002

      SIGA Technologies and Allergy Therapeutics Holdings Announce Intent to
Merge

      New York, USA and Worthing, UK - SIGA Technologies, Inc. (NASDAQ:SIGA and
FRANKFURT: SGW 919 473) and Allergy Therapeutics Holdings Ltd. announced today
they have signed a non-binding letter of intent to combine the two companies. As
part of the transaction, Elan Corporation through its subsidiaries, has agreed
to expand its existing strategic collaboration with Allergy Therapeutics and
license additional vaccine-related technology to the combined company on an
exclusive basis.

      The letter of intent contemplates a stock-for-stock transaction in which,
assuming the exercise of certain outstanding options, the current SIGA
shareholders, on the one hand, and the current Allergy Therapeutics
shareholders, on the other hand, will each own 47.5% of the combined company and
Elan Corporation will own 5% of the combined company.

      The transaction is subject to certain conditions, including the completion
of due diligence, the negotiation and execution of definitive agreements,
obtaining any necessary regulatory approvals and the approval of the transaction
by SIGA's and Allergy Therapeutics' respective shareholders.

      Donald G. Drapkin, Chairman of the Board of SIGA said, "Allergy
Therapeutics has an established business in Europe and a first-class management
team with an international pedigree. By combining Allergy Therapeutics' existing
business and its new product pipeline for allergic disease with SIGA's highly
innovative vaccine technology base in infectious disease, we intend to build a
company with a growing sales base and a novel product development pipeline. The
Board of SIGA believes the combined company will be positioned to become a major
international vaccine provider."

      Iain G Ross, Chairman & CEO of Allergy Therapeutics said "This is an
excellent opportunity for our shareholders as there is a strong science based
complementary fit between the two companies founded on the fundamental
immunological basis of both infectious and allergic disease." Ross continued,
"From the outset, the combined company will focus on the development of
innovative products for the treatment and prevention of infectious and allergic
disease. As we will have a wealth of product, technology and intellectual
property assets, our

<PAGE>

letter of intent contemplates a further potential transaction. Our current
thinking is that, after having fully evaluated the opportunities as a combined
company, we anticipate transferring certain non-vaccine assets into a newly
formed spin-off company."

      SIGA is a development stage technology company, whose primary focus is on
biopharmaceutical product development. SIGA is engaged in the discovery,
development and commercialization of vaccines, antibiotics and novel
anti-infectives for serious infectious diseases. SIGA's lead vaccine candidate
is for the prevention of group A streptococcal pharyngitis or "strep throat" and
SIGA is also developing a technology for the mucosal delivery of vaccines which
may allow vaccines to activate the immune system at the mucus lined surfaces of
the body - the mouth, the nose, the lungs and gastrointestinal and urogenital
tracts - the sites of entry for most infectious agents. In addition, SIGA has
anti-infective programs aimed at the increasingly serious problem of drug
resistance.

      Allergy Therapeutics is a private European based specialty pharmaceutical
company focused on the treatment and prevention of allergy. Shareholders include
GlaxoSmithKline, Elan Corporation and ING Bank. Allergy Therapeutics has
turnover in excess of $20 million per annum through the sale of registered and
named patient vaccines for the treatment of severe allergies to grass and tree
pollens, house dust mites and bee and wasp venoms. Allergy Therapeutics has an
established GMP manufacturing facility and a Sales & Marketing infrastructure in
several European countries including Germany, Italy and Spain. A number of novel
compounds have undergone initial clinical evaluation, and Allergy Therapeutics
plans to commence phase III clinical studies with at least one novel allergy
vaccine before the end of 2002.

      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 transaction contemplated by the letter
of intent 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 or Allergy
Therapeutics. 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, Allergy
Therapeutics or their respective collaborators in early research or clinical
trials do not demonstrate efficacy or safety in subsequent pre-clinical or
clinical trials and that SIGA, Allergy Therapeutics or their respective
collaborators will not obtain appropriate or necessary government approvals to
market products tested in such trials; and that the completion to each party's
satisfaction of due diligence, the negotiation and execution of definitive
documents, 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 any proxy
statement/prospectus that may be sent to SIGA shareholders regarding the
proposed transaction, when and if any such proxy statement/prospectus becomes
available, because such proxy statement/prospectus will contain important
information. Any such proxy statement/prospectus will be filed with the
Securities and Exchange Commission by SIGA. Investors and security holders may
obtain a free copy of the

<PAGE>

proxy statement/prospectus, when and if such proxy statement/prospectus is
available, and any other documents filed by SIGA with the Commission at the
Commission's web site at www.sec.gov. Any such proxy statement/prospectus and
these other documents may also be obtained, when and if available, free of
charge from SIGA. SIGA's shareholders should read any such proxy
statement/prospectus carefully before making a decision concerning the
transaction.

      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 transaction. 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 transaction is set forth in SIGA's proxy statement for its 2001 annual
meeting, and additional information will be set forth in the definitive proxy
statement/prospectus referred to above when and if 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, 2000, 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. For more information
about SIGA, please visit SIGA's website at www.siga.com.


<PAGE>

                                                                    NEWS RELEASE
--------------------------------------------------------------------------------

CONTACTS:                                     FOR IMMEDIATE RELEASE

SIGA Technologies, Inc.                       Allergy Therapeutics
Thomas N. Konatich                            Iain G. Ross
CFO & Acting CEO                              Chairman & CEO
(212) 672-9100                                +44 (0) 1903-844720
tkonatich@siga.com                            iain.ross@allergytherapeutics.com
------------------                            ---------------------------------

          SIGA TECHNOLOGIES AND ALLERGY THERAPEUTICS HOLDINGS ANNOUNCE
                                INTENT TO MERGE

New York, NY, March 11, 2002 -- SIGA Technologies, Inc. (NASDAQ: SIGA) and
(FRANKFURT: SGW 919 473) and Allergy Therapeutics Holdings Ltd. announced today
they have signed a non-binding letter of intent to combine the two companies. As
part of the transaction, Elan Corporation, through its subsidiaries, has agreed
to expand its strategic collaboration with Allergy Therapeutics and license
additional vaccine-related technology to the combined company on an exclusive
basis.

The letter of intent contemplates a stock-for-stock transaction in which,
assuming the exercise of certain outstanding options, the current SIGA
shareholders, on the one hand, and the current Allergy Therapeutics
shareholders, on the other hand, will each own 47.5% of the combined company and
Elan Corporation will own 5% of the combined company.

The transaction is subject to certain conditions, including the completion of
due diligence, the negotiation and execution of definitive agreements, obtaining
any necessary regulatory approvals and the approval of the transaction by SIGA's
and Allergy Therapeutics' respective shareholders.

Donald G. Drapkin, Chairman of the Board of SIGA said, "Allergy Therapeutics has
an established business in Europe and a first-class management team with an
international pedigree. By combining Allergy Therapeutics' existing business and
its new product pipeline for allergic disease with SIGA's highly innovative
vaccine technology base in infectious disease, we intend to build a company with
a growing sales base and a novel product development pipeline. The Board of SIGA
believes the combined company will be positioned to become a major international
vaccine provider."

Iain G Ross, Chairman & CEO of Allergy Therapeutics said "This is an excellent
opportunity for our shareholders as there is a strong science based
complementary fit between the two companies founded on the fundamental
immunological basis of both infectious and allergic disease." Ross continued,
"From the outset, the combined company will focus on the development of
innovative products for the treatment and prevention of infectious and allergic
disease. As we will have a wealth of product, technology and intellectual
property assets, our letter of intent contemplates a further potential
transaction. Our current thinking is that, after having fully evaluated the
opportunities as a combined company, we anticipate transferring certain
non-vaccine assets into a newly formed spin-off company."

<PAGE>

SIGA is a development stage technology company, whose primary focus is on
biopharmaceutical product development. SIGA is engaged in the discovery,
development and commercialization of vaccines, antibiotics and novel
anti-infectives for serious infectious diseases. SIGA's lead vaccine candidate
is for the prevention of group A streptococcal pharyngitis or "strep throat" and
SIGA is also developing a technology for the mucosal delivery of vaccines which
may allow vaccines to activate the immune system at the mucus lined surfaces of
the body - the mouth, the nose, the lungs and gastrointestinal and urogenital
tracts - the sites of entry for most infectious agents. In addition, SIGA has
anti-infective programs aimed at the increasingly serious problem of drug
resistance.

Allergy Therapeutics is a private European based specialty pharmaceutical
company focused on the treatment and prevention of allergy. Shareholders include
GlaxoSmithKline, Elan Corporation and ING Bank. Allergy Therapeutics has
turnover in excess of $20 million per annum through the sale of registered and
named patient vaccines for the treatment of severe allergies to grass and tree
pollens, house dust mites and bee and wasp venoms. Allergy Therapeutics has an
established GMP manufacturing facility and a Sales & Marketing infrastructure in
several European countries including Germany, Italy and Spain. A number of novel
compounds have undergone initial clinical evaluation and Allergy Therapeutics
plans to commence phase III clinical studies with at least one novel allergy
vaccine before the end of 2002.

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 transaction contemplated by the letter
of intent 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 or Allergy
Therapeutics. 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, Allergy
Therapeutics or their respective collaborators in early research or clinical
trials do not demonstrate efficacy or safety in subsequent pre-clinical or
clinical trials and that SIGA, Allergy Therapeutics or their respective
collaborators will not obtain appropriate or necessary government approvals to
market products tested in such trials; and that the completion to each party's
satisfaction of due diligence, the negotiation and execution of definitive
documents, 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 any proxy statement/prospectus
that may be sent to SIGA shareholders regarding the proposed transaction, when
and if any such proxy statement/prospectus becomes available, because such proxy
statement/prospectus will contain important information. Any such proxy
statement/prospectus will be filed with the Securities and Exchange Commission
by SIGA. Investors and security holders may obtain a free copy of the proxy
statement/prospectus, when and if such proxy statement/prospectus is available,
and any other documents filed by SIGA with the Commission at the Commission's
web site at www.sec.gov. Any such proxy statement/prospectus and these other
documents may also be


                                                                               2
<PAGE>

obtained, when and if available, free of charge from SIGA. SIGA's shareholders
should read any such proxy statement/prospectus carefully before making a
decision concerning the transaction.

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 transaction. 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 transaction is set forth in SIGA's proxy statement for its 2001 annual
meeting, and additional information will be set forth in the definitive proxy
statement/prospectus referred to above when and if 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, 2000, 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. For more information
about SIGA, please visit SIGA's website at www.siga.com.

                                       ###


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