Progenics and Wyeth Announce FDA Has Approved RELISTOR

First Drug for Opioid-Induced Constipation to Launch in United
States
TARRYTOWN, N.Y. & COLLEGEVILLE, Pa.--(Business Wire)--
Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX) and Wyeth
Pharmaceuticals, a division of Wyeth (NYSE: WYE), today announced that
the U.S. Food and Drug Administration (FDA) has approved RELISTOR(TM)
(methylnaltrexone bromide) 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. In clinical studies, RELISTOR significantly
decreased the constipating effects of opioids without interfering with
pain relief. Wyeth expects to make RELISTOR available in the United
States in early June.

"The approval of RELISTOR is a transformative event for Progenics
Pharmaceuticals," says Paul J. Maddon, M.D., Ph.D., Founder, Chief
Executive Officer and Chief Science Officer, Progenics
Pharmaceuticals, Inc. "This is our first U.S. product approval. I am
proud of what our Company has achieved and especially want to thank
our patients and investigators who participated in the RELISTOR
development program. This program has greatly benefited from our
collaboration with Wyeth to develop and commercialize the RELISTOR
platform of products."

Each year, more than 1.5 million Americans receive palliative care
due to an advanced illness, such as incurable cancer, end-stage heart
and lung disease, or AIDS. Many of these patients are prescribed
opioids to manage their pain, and experts have stated that
constipation that can be debilitating occurs in practically all of
them.

"We are pleased to make RELISTOR available to patients to address
this serious unmet medical need," says Bernard Poussot, President and
Chief Executive Officer, Wyeth. "As Wyeth's third new medicine to
receive FDA approval in 2008, RELISTOR is an excellent example of
Wyeth's continuing commitment to develop and deliver medicines that
work in novel ways and provide important new treatment options for
patients."

Jay Thomas, M.D., Ph.D., an investigator in the subcutaneous
RELISTOR clinical trial program and Clinical Medical Director of San
Diego Hospice and the Institute of Palliative Medicine, says: "Opioid
analgesics are the mainstay therapy for pain management in
advanced-illness patients receiving palliative care. Side effects
associated with opioids, such as constipation, can be severe enough to
limit pain management. I am pleased that we now have a new treatment
option to provide relief to advanced-illness patients with OIC."

About RELISTOR and Opioids

RELISTOR, administered via subcutaneous injection, is a
peripherally acting mu-opioid receptor antagonist that counteracts the
constipating effects of opioid pain medications in the
gastrointestinal tract without affecting their ability to relieve
pain.

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. RELISTOR 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, RELISTOR does not affect the
opioid-mediated analgesic effects on the CNS. The efficacy and safety
profile of RELISTOR was established in two phase 3 clinical trials.
Use of RELISTOR beyond four months has not been studied.

Important Safety Information for 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 with RELISTOR in clinical
trials were abdominal pain, flatulence, and nausea.

RELISTOR Prescribing Information will be available at
www.relistor.com.

About the Collaboration

In December 2005, Wyeth and Progenics Pharmaceuticals entered into
an exclusive, worldwide agreement for the joint development and
commercialization of methylnaltrexone for the treatment of
opioid-induced side effects. In accordance with the terms of the
collaboration, this U.S. marketing approval triggers a $15 million
milestone payment to Progenics from Wyeth.

(PGNX-G)

About the Companies

Wyeth Pharmaceuticals, a division of Wyeth, has leading products
in the areas of women's health care, infectious disease,
gastrointestinal health, central nervous system, inflammation,
transplantation, hemophilia, oncology, vaccines and nutritional
products. Wyeth is one of the world's largest research-driven
pharmaceutical and health care products companies. It is a leader in
the discovery, development, manufacturing and marketing of
pharmaceuticals, vaccines, biotechnology products, nutritionals and
non-prescription medicines that improve the quality of life for people
worldwide. The Company's major divisions include Wyeth
Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal
Health.

WYETH DISCLOSURE NOTICE: The statements in this press release that
are not historical facts are forward-looking statements that are
subject to risks and uncertainties that could cause actual results to
differ materially from those expressed or implied by such statements.
In particular, there can be no assurance that RELISTOR will be
commercially successful or that RELISTOR will be approved in the
future in other formulations or indications and/or in other countries.
Other risks and uncertainties that could cause actual results to
differ materially from those expressed or implied by forward-looking
statements include, without limitation, the inherent uncertainty of
the timing and success of, and expense associated with, research,
development, regulatory approval and commercialization of our products
and pipeline products; government cost-containment initiatives;
restrictions on third-party payments for our products; substantial
competition in our industry, including from branded and generic
products; emerging data on our products and pipeline products; the
importance of strong performance from our principal products and our
anticipated new product introductions; the highly regulated nature of
our business; product liability, intellectual property and other
litigation risks and environmental liabilities; uncertainty regarding
our intellectual property rights and those of others; difficulties
associated with, and regulatory compliance with respect to,
manufacturing of our products; risks associated with our strategic
relationships; economic conditions including interest and currency
exchange rate fluctuations; changes in generally accepted accounting
principles; trade buying patterns; the impact of legislation and
regulatory compliance; risks and uncertainties associated with global
operations and sales; and other risks and uncertainties, including
those detailed from time to time in our periodic reports filed with
the Securities and Exchange Commission, including our current reports
on Form 8-K, quarterly reports on Form 10-Q and annual report on Form
10-K, particularly the discussion under the caption "Item 1A, RISK
FACTORS" in our Annual Report on Form 10-K for the year ended December
31, 2007, which was filed with the Securities and Exchange Commission
on February 29, 2008. The forward-looking statements in this press
release are qualified by these risk factors. We assume no obligation
to publicly update any forward-looking statements, whether as a result
of new information, future developments or otherwise.

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
gastroenterology as well as the treatment of HIV infection and cancer.
The Company, in collaboration with Wyeth, is developing RELISTOR for
the treatment of opioid-induced side effects, including constipation
(oral and subcutaneous formulations) and postoperative ileus
(intravenous formulation). In the area of HIV infection, the Company
is developing the viral-entry inhibitor PRO 140, a humanized
monoclonal antibody targeting the HIV entry co-receptor CCR5, which
has completed phase 1b clinical studies with positive results. In the
area of prostate cancer, the Company is developing a human monoclonal
antibody drug conjugate - a selectively targeted cytotoxic antibody
directed against prostate-specific membrane antigen (PSMA), a protein
found on the surface of prostate cancer cells. Progenics is also
developing vaccines designed to stimulate an immune response to PSMA.

PROGENICS DISCLOSURE NOTICE: The information contained in this
document is current as of April 25, 2008. This press release contains
forward-looking statements. Any statements contained herein that are
not statements of historical fact may be forward-looking statements.
When the Company uses the words "anticipates," "plans," "expects" and
similar expressions, it is identifying forward-looking statements.
Such forward-looking statements involve risks and uncertainties which
may cause the Company's actual results, performance or achievements to
be materially different from those expressed or implied by
forward-looking statements. Such factors include, among others, the
uncertainties associated with product development, the risk that
clinical trials will not commence or proceed as planned, the risks and
uncertainties associated with dependence upon the actions of our
corporate, academic and other collaborators and of government
regulatory agencies, the risk that our licenses to intellectual
property may be terminated because of our failure to have satisfied
performance milestones, the risk that products that appear promising
in early clinical trials do not demonstrate efficacy in larger-scale
clinical trials, the risk that we may not be able to manufacture
commercial quantities of our products, the uncertainty of future
profitability and other factors set forth more fully in the Company's
Annual Report on Form 10-K for the fiscal year ended December 31,
2007, and other reports filed with the Securities and Exchange
Commission, to which investors are referred for further information.
In particular, the Company cannot assure you that any of its programs
will result in a commercial product. Progenics does not have a policy
of updating or revising forward-looking statements and assumes no
obligation to update any forward-looking statements contained in this
document as a result of new information or future events or
developments. Thus, it should not be assumed that the Company's
silence over time means that actual events are bearing out as
expressed or implied in such forward-looking statements.

Editor's Note:

Additional information on Progenics available at
www.progenics.com

Additional information on Wyeth available at www.wyeth.com

Progenics Pharmaceuticals, Inc.
Investors:
Richard W. Krawiec, Ph.D., 914-789-2814
Vice President, Corporate Affairs
rkrawiec@progenics.com
or
Dory A. Lombardo, 914-789-2818
Senior Manager, Corporate Affairs
dlombardo@progenics.com
or
WeissComm Partners
Media:
Aline Schimmel, 312-284-4706
aschimmel@wcpglobal.com
or
Julie Normart, 415-946-1087
or
Wyeth Pharmaceuticals
Media:
Sal Foti, 484-865-3490
or
Douglas Petkus, 973-660-5218
or
Investors:
Justin Victoria, 973-660-5340

Copyright Business Wire 2008