Contacts:
            Progenics
      Pharmaceuticals, Inc.:
              Dory
      A. Kurowski
              Director
              Corporate
      Affairs
              (914)
      789-2818
              dkurowski@progenics.com
              
              Media
      Contact:
              Aline
      Schimmel
              WCG
              (312)
      646-6295
              aschimmel@wcgworld.com





PROGENICS TO ADVANCE ORAL
METHYLNALTREXONE INTO LATE STAGE CLINICAL DEVELOPMENT





– Phase 2b/3 trial to begin later
this year –





Tarrytown, NY – March 12, 2010
– Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX) today announced that it plans
to advance oral methylnaltrexone for the treatment of opioid-induced
constipation (OIC) into late stage clinical development and will commence a
phase 2b/3 clinical trial of a methylnaltrexone tablet in chronic-pain patients
in the second half of 2010.  Progenics also announced data from a
clinical trial of this methylnaltrexone tablet.





The
tablet form of oral methylnaltrexone was developed by Progenics’ former
collaboration partner Wyeth. At the time of Wyeth’s acquisition by Pfizer in
October 2009, Progenics regained from Wyeth the rights to methylnaltrexone,
including rights to this methylnaltrexone tablet. The transfer of data and
information to Progenics regarding Wyeth’s work on oral methylnaltrexone was
recently completed and Progenics has now had the opportunity to review in detail
information regarding the methylnaltrexone tablet which is being reported on
today.





The study of the methylnaltrexone
tablet was conducted in subjects with chronic, non-cancer pain receiving various
opioid treatment regimens. Study inclusion criteria required subjects to have a
history of OIC. Subjects were administered a single methylnaltrexone tablet at
different dose levels following an overnight fast. Forty-eight percent of
subjects receiving one of the doses (n=25) laxated within four hours of
treatment.





Progenics’
analysis and next steps for the methylnaltrexone tablet





Based on
the study data reported in this release and other information regarding oral
methylnaltrexone, Progenics believes that the methylnaltrexone tablet is active
and generally well tolerated. Both the time to onset of action demonstrated in
this study and the percentage of patients who had responded within four hours
are consistent with that previously shown in clinical trials of subcutaneous
methylnaltrexone.








“We believe that the activity
demonstrated to date by the methylnaltrexone tablet shares the hallmarks of
methylnaltrexone: both a prompt onset of action and a predictable response for a
large percentage of patients,” said Paul J. Maddon, M.D., Ph.D., Founder, Chief
Executive Officer and Chief Science Officer of Progenics. “Our next step is to
initiate a phase 2b/3 dose-optimizing clinical trial in chronic-pain patients
with OIC in the second half of this year to confirm these results.”





The tablets to be used in Progenics’
planned phase 2b/3 trial were produced by Wyeth at Wyeth’s cost as provided for
under the provisions of the termination of the collaboration between the two
companies.




About
Opioids and Opioid-Induced Constipation






Opioids
are considered to be effective analgesics for the management of
moderate-to-severe pain, and one of the most common side effects of opioids is
constipation. Opioids provide pain relief by specifically interacting with
mu-opioid receptors within the central nervous system (CNS) - the brain and
spinal cord. However, opioids also interact with mu-opioid receptors found
outside the CNS, such as those within the gastrointestinal tract, resulting in
constipation that can be debilitating.






About
Methylnaltrexone




Methylnaltrexone
selectively displaces opioids from the mu-opioid receptors outside the CNS,
including those located in the gastrointestinal tract, thereby decreasing their
constipating effects. Because of its chemical structure, methylnaltrexone does
not affect the opioid-mediated analgesic effects on the CNS.





About
Subcutaneous RELISTOR





RELISTOR
(methylnaltrexone bromide or “methylnaltrexone”), administered via subcutaneous
injection, is a peripherally acting mu-opioid receptor antagonist that decreases
the constipating effects of opioid pain medications in the gastrointestinal
tract without affecting their ability to relieve pain.





In April
of 2008, the U.S. Food and Drug Administration approved RELISTOR subcutaneous
injection for the treatment of opioid-induced constipation (OIC) in patients
with advanced illness who are receiving palliative care, when response to
laxative therapy has not been sufficient. The use of RELISTOR beyond four months
has not been studied. RELISTOR is now approved in over 40 countries, including
the U.S., Canada, the European Union, Latin American countries and Australia.
Other applications in additional countries are also pending.








Important
Safety Information for Subcutaneous RELISTOR





·
            RELISTOR
      is contraindicated in patients with known or suspected mechanical
      gastrointestinal obstruction.


·
            If
      severe or persistent diarrhea occurs during treatment, advise patients to
      discontinue therapy with RELISTOR and consult their
    physician.


·
            Use
      of RELISTOR has not been studied in patients with peritoneal
      catheters.


·
            The
      most common adverse reactions reported with RELISTOR compared with placebo
      in clinical trials were abdominal pain (28.5% vs 9.8%), flatulence (13.3%
      vs 5.7%), nausea (11.5% vs 4.9%), dizziness (7.3% vs 2.4%), diarrhea (5.5%
      vs 2.4%), and hyperhidrosis (6.7% vs
6.5%).


·
            Full
      RELISTOR Prescribing Information for the U.S. is available at www.relistor.com.





(PGNX-C)





About
Progenics





Progenics Pharmaceuticals,
Inc., of Tarrytown, NY, is a biopharmaceutical company focusing on the
development and commercialization of innovative therapeutic products to treat
the unmet medical needs of patients with debilitating conditions and
life-threatening diseases. Principal programs are directed toward supportive
care, oncology and virology. Progenics is developing RELISTOR®
(methylnaltrexone bromide) for the treatment of opioid-induced side effects.
RELISTOR is now approved in over 40 countries, including the U.S., Canada, the
European Union, Latin American countries and Australia. Progenics is pursuing
strategic alternatives for RELISTOR, including licensing, collaboration,
strategic alliances and U.S. commercialization or co-promotion, following
termination of its 2005 collaboration with Wyeth Pharmaceuticals, which is
continuing manufacturing, sales, marketing, and certain development and
regulatory activities for RELISTOR during the transition. Ono Pharmaceutical
Co., Ltd. has an exclusive license from Progenics for development and
commercialization of subcutaneous RELISTOR in Japan. In oncology, the Company is
conducting a phase 1 clinical trial of a human monoclonal antibody-drug
conjugate (ADC) for the treatment of prostate cancer—a selectively targeted
chemotherapeutic antibody directed against prostate-specific membrane antigen.
PSMA is a protein found on the surface of prostate cancer cells as well as in
blood vessels supplying other solid tumors. Progenics is also conducting phase 1
clinical trials with vaccines designed to treat prostate cancer by stimulating
an immune response to PSMA in immunized subjects. Progenics is also developing
novel multiplex PI3-Kinase inhibitors as a potential strategy to combat some of
the most aggressive forms of cancer. In virology, Progenics is developing the
viral-entry inhibitor PRO 140, a humanized monoclonal antibody which binds to
co-receptor CCR5 to inhibit human immunodeficiency virus (HIV) infection. PRO
140 is currently in phase 2 clinical testing. The Company’s hepatitis C virus
discovery program seeks to identify novel inhibitors of HCV entry.





PROGENICS DISCLOSURE NOTICE:
This document contains statements that do not relate strictly to historical
fact, any of which may be forward-looking statements within the meaning of the
U.S. Private Securities Litigation Reform Act of 1995. When we use the words
“anticipates,” “plans,” “expects” and similar expressions, we are identifying
forward-looking statements. Forward-looking statements involve known and unknown
risks and uncertainties which may cause our actual results, performance or
achievements to be materially different from those expressed or implied by
forward-looking statements. While it is impossible to identify or predict all
such matters, these differences may result from, among other things, the
inherent uncertainty of the timing and success of, and expense associated with,
research, development, regulatory approval and commercialization of our products
and product candidates, including the risks that clinical trials will not
commence or proceed as planned; products appearing promising in early trials
will not demonstrate efficacy or safety in larger-scale trials; clinical trial
data on our products and product candidates will be unfavorable; our products
will not receive marketing approval from regulators or, if approved, do not gain
sufficient market acceptance to justify development and commercialization costs;
competing products currently on the market or in development might reduce the
commercial potential of our products; we, our collaborators or others might
identify side effects after the product is on the market; or efficacy or safety
concerns regarding marketed products, whether or not originating from subsequent
testing or other activities by us, governmental regulators, other entities or
organizations or otherwise, and whether or not scientifically justified, may
lead to product recalls, withdrawals of marketing approval, reformulation of the
product, additional pre-clinical testing or clinical trials, changes in labeling
of the product, the need for additional marketing applications, declining sales
or other adverse events.








We
are also subject to risks and uncertainties associated with the actions of our
corporate, academic and other collaborators and government regulatory agencies,
including risks from market forces and trends; potential product liability;
intellectual property, litigation, environmental and other risks; the risk that
we may not be able to enter into favorable collaboration or other relationships
or that existing or future relationships may not proceed as planned; the risk
that current and pending patent protection for our products may be invalid,
unenforceable or challenged, or fail to provide adequate market exclusivity, or
that our rights to in-licensed intellectual property may be terminated for our
failure to satisfy performance milestones; the risk of difficulties in, and
regulatory compliance relating to, manufacturing products; and the uncertainty
of our future profitability.





Risks
and uncertainties also include general economic conditions, including interest
and currency exchange-rate fluctuations and the availability of capital; changes
in generally accepted accounting principles; the impact of legislation and
regulatory compliance; the highly regulated nature of our business, including
government cost-containment initiatives and restrictions on third-party payments
for our products; trade buying patterns; the competitive climate of our
industry; and other factors set forth in our Annual Report on Form 10-K and
other reports filed with the U.S. Securities and Exchange Commission. In
particular, we cannot assure you that RELISTOR will be commercially successful
or be approved in the future in other formulations, indications or
jurisdictions, or that any of our other programs will result in a commercial
product.





We
do not have a policy of updating or revising forward-looking statements and we
assume no obligation to update any statements as a result of new information or
future events or developments. It should not be assumed that our silence over
time means that actual events are bearing out as expressed or implied in
forward-looking statements.





###








Editor’s
Note:


For
further information, please visit www.progenics.com