PharmAthene and Medarex Announce FY 2008 U.S. Congressional Appropriation of up to $1.6 Million for Continued Development of Anthrax Therapeutic Valortim(TM)

PharmAthene and Medarex Announce FY 2008 U.S. Congressional Appropriation of up to $1.6 Million for Continued Development of Anthrax Therapeutic Valortim(TM)
ANNAPOLIS, Md. and PRINCETON, N.J., Jan 08, 2008 /PRNewswire-FirstCall via COMTEX
News Network/ -- PharmAthene, Inc., (Amex: PIP) a biodefense company developing
medical countermeasures against biological and chemical threats, and Medarex, Inc.
(Nasdaq: MEDX), a leading monoclonal antibody company, today announced that the FY
2008 U.S. Congressional appropriation for the Department of Defense (DoD) includes
up to $1.6 million payable to PharmAthene on a cost reimbursement basis to support
ongoing development of Valortim(TM), a fully human monoclonal antibody generated by
Medarex's UltiMAb(R) technology that is being co-developed by the two companies for
the prevention and treatment of anthrax infection.

David P. Wright, President and Chief Executive Officer of PharmAthene commented,
"We're very pleased by the U.S. Government's ongoing support of Valortim and
commitment to advancing this important product for consideration as part of our
Nation's arsenal to protect against the devastating consequences of an anthrax
attack. Total government funding pledged in support of Valortim over the last four
fiscal years is up to $23 million, excluding this FY 08 appropriation."

Mr. Wright continued, "Valortim has demonstrated potent activity in neutralizing the
anthrax toxin in preclinical studies as well as favorable safety data collected from
our Phase I clinical study. We believe that Valortim may have important competitive
advantages which, if demonstrated, would make it a strong choice for procurement
consideration in the Strategic National Stockpile."

"This funding will contribute to the continued development of this potentially
important biodefense product.  Together with PharmAthene we continue to advance the
development of Valortim and believe that data collected to date -- from preclinical
and clinical research -- show that Valortim could become an important part of the
government's biodefense program to prevent and treat anthrax infection," said Israel
Lowy, M.D., Ph.D., Senior Director of Infectious Disease for Medarex.

About Valortim

Valortim (MDX-1303) is a fully human antibody designed to protect against anthrax
infection, including inhalation anthrax, the most lethal form of illness in humans
caused by the Bacillus anthracis bacterium.  The investigational antibody is
designed to target a protein component known as the anthrax protective antigen (PA)
of the lethal toxin complex produced by the bacterium.  The anthrax protective
antigen is believed to initiate the onset of the illness by attaching to cells in
the infected person, and then is believed to facilitate the entry of additional
destructive toxins into the cells.  Valortim is designed to target anthrax
protective antigen and protect the cells from damage by the anthrax toxins.

Valortim has been administered intravenously and intramuscularly to healthy human
volunteers in a completed phase I study, was well tolerated at doses as high as 20
mg/kg (IV), and was not immunogenic. These study results were presented at the 2006
Annual Meeting of the Infectious Diseases Society of America. Pharmacokinetic
analysis suggested that doses as low as 1 mg/kg resulted in circulating levels of
antibody after a month, with a similar potency for neutralizing anthrax toxin in
vitro as was seen with serum obtained from subjects who had been vaccinated with
anthrax vaccine.

Preclinical studies suggest that Valortim has the potential to provide significant
protection against anthrax infection when administered prophylactically (prior to
the emergence of symptoms of anthrax infection) and also may increase survival when
administered therapeutically (once symptoms become evident).

About Anthrax

According to the Centers for Disease Control and Prevention, anthrax is an acute
infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax
most commonly occurs in hoofed mammals and can also infect humans. Symptoms of
disease vary depending on how the disease is contracted, but usually occur within
seven days after exposure. The serious forms of human anthrax are inhalation
anthrax, cutaneous anthrax, and intestinal anthrax. Initial symptoms of inhalation
anthrax infection may resemble a common cold. After several days, the symptoms may
progress to severe breathing problems and shock. Inhalation anthrax is often fatal,
even if treated by antibiotics. Currently, antibiotics are the only drugs available
for therapeutic or prophylactic use, and post-exposure prophylaxis is the only
FDA-approved indication for such products.  However, antibiotic therapy, while
useful, is believed to be associated with a number of limitations, including: (1)
lack of activity against the toxins produced by the B. anthracis bacteria (2) need
for long-term dosing to achieve full protection, complicated by side effects and
non-compliance (3) lack of efficacy when administered late in the anthrax disease
cycle, and (4) lack of effectiveness against multi-drug resistant or genetically
engineered strains of anthrax.

About PharmAthene, Inc.

PharmAthene (Amex: PIP) was formed to meet the critical needs of the United States
and its allies by developing and commercializing medical countermeasures against
biological and chemical weapons.  PharmAthene's lead programs include Valortim(TM)
for the prevention and treatment of anthrax infection and Protexia(R) for the
prevention and treatment of morbidity and mortality associated with exposure to
chemical nerve agents. For more information on PharmAthene, please visit
www.PharmAthene.com.

About Medarex, Inc.

Medarex is a biopharmaceutical company focused on the discovery, development and
potential commercialization of fully human antibody-based therapeutics to treat
life-threatening and debilitating diseases, including cancer, inflammation,
autoimmune disorders and infectious diseases. Medarex applies its UltiMAb(R)
technology and product development and clinical manufacturing experience to
generate, support and potentially commercialize a broad range of fully human
antibody product candidates for itself and its partners. More than 30 of these
therapeutic product candidates derived from Medarex technology are in human clinical
testing or have had INDs submitted for such trials, with seven of the most advanced
product candidates currently in Phase III clinical trials. Medarex is committed to
building value by developing a diverse pipeline of antibody products to address the
world's unmet healthcare needs. For more information about Medarex, visit its
website at www.medarex.com.

Statement on Cautionary Factors

For PharmAthene:  Except for the historical information presented herein, matters
discussed may constitute forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995 that are subject to certain risks
and uncertainties that could cause actual results to differ materially from any
future results, performance or achievements expressed or implied by such statements.
 Statements that are not historical facts, including statements preceded by,
followed by, or that include the words "potential"; "believe"; "anticipate";
"intend"; "plan"; "expect"; "estimate"; "could"; "may"; "should"; "could"; or
similar statements are forward-looking statements.  PharmAthene disclaims, however,
any intent or obligation to update these forward-looking statements.  Risks and
uncertainties include risks associated with the reliability of the results of the
studies relating to human safety and possible adverse effects resulting from the
administration of Valortim in humans, timely and successful development of an
efficient and scalable manufacturing process, unexpected funding delays by
NIAID/BARDA, unforeseen safety issues resulting from the handling of Bacillus
anthracis, as well as risks detailed from time to time in PharmAthene's public
disclosure filings with the U.S. Securities and Exchange Commission (the "SEC"). 
There can be no assurance that such development efforts will succeed or that other
developed products will receive required regulatory clearance or that, even if such
regulatory clearance were received, such products would ultimately achieve
commercial success.  Copies of PharmAthene's public disclosure filings are available
from its investor relations department.

For Medarex:  Except for the historical information presented herein, matters
discussed herein may constitute forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995 that are subject to certain risks
and uncertainties that could cause actual results to differ materially from any
future results, performance or achievements expressed or implied by such statements.
 Statements that are not historical facts, including statements preceded by,
followed by, or that include the words "potential"; "believe"; "suggest"; "may";
"appear"; or similar statements are forward-looking statements.  Medarex disclaims,
however, any intent or obligation to update these forward-looking statements, except
as required by law.  Risks and uncertainties include risks associated with the
reliability of the results of the initial work conducted on Valortim relating to
animal efficacy, human safety and likelihood of successful development of an
efficient and scalable manufacturing process, unexpected funding delays by
NIAID/BARDA, unforeseen safety issues resulting from the handling of Bacillus
anthracis, unforeseen safety issues resulting from the administration of
Valortim(TM) (MDX-1303) in human subjects, uncertainties related to product
manufacturing as well as risks detailed from time to time in Medarex's public
disclosure filings with the U.S. Securities and Exchange Commission (SEC), including
its Annual Report on Form 10-K for the fiscal year ended December 31, 2006 and its
quarterly reports on Form 10-Q.  There can be no assurance that such development
efforts will succeed or that other developed products will receive required
regulatory clearance or that, even if such regulatory clearance were received, such
products would ultimately achieve commercial success.  Copies of Medarex's public
disclosure filings are available from its investor relations department.

Medarex(R), the Medarex logo and UltiMAb(R) are registered trademarks of Medarex,
Inc. All rights are reserved. Valortim(TM) is a trademark of PharmAthene, Inc.  All
rights are reserved.

SOURCE  Medarex, Inc. and PharmAthene, Inc.

http://www.medarex.com