Progenics Pharmaceuticals Presents Updated Data From Phase 1 Study of PSMA ADC

Progenics Pharmaceuticals Presents Updated Data From Phase 1 Study of PSMA ADC

 - Outcomes From Clinical Study in Prostate Cancer Presented at Genitourinary
                             Cancers Symposium -

TARRYTOWN, N.Y., Feb. 14, 2013 (GLOBE NEWSWIRE) -- Progenics Pharmaceuticals,
Inc. (Nasdaq:PGNX) today reported positive clinical data from a completed
phase 1 study of PSMA ADC, an antibody-drug conjugate (ADC) designed to
selectively deliver chemotherapy to cells that express prostate-specific
membrane antigen (PSMA). PSMA ADC was generally well tolerated in patients at
doses up to and including 2.5 mg/kg, the maximum tolerated dose. Findings were
presented at the 2013 Genitourinary Cancers Symposium, a meeting co-sponsored
by the American Society of Clinical Oncology (ASCO), the American Society for
Radiation Oncology (ASTRO) and the Society of Urologic Oncology (SUO).

Fifty-two patients with metastatic castration-resistant prostate cancer
(mCRPC) were dosed at nine dose levels. Significant antitumor activity was
observed across doses ranging from 1.8 mg/kg to 2.8 mg/kg. Dose limiting
toxicities, primarily neutropenia, were seen at 2.8 mg/kg. The most commonly
reported adverse events were anorexia and fatigue.

A poster entitled "Prostate-Specific Membrane Antigen Antibody Drug Conjugate
(PSMA ADC): A Phase 1 Trial in Subjects with Metastatic Castration-Resistant
Prostate Cancer (mCRPC) Previously Treated with Taxane" is being presented
today by Daniel P. Petrylak, M.D., Director of the Prostate Cancer
Program/Genitourinary Cancer Program and Co-Director of the Signal
Transduction Program at Yale University Medical Center. This poster will be
available for the next 30 days on the Events page at www.progenics.com.

Progenics opened enrollment in a subsequent phase 2 study of PSMA ADC in
September 2012. This ongoing trial is an open-label, multicenter study
assessing the anti-tumor activity and tolerability of PSMA ADC in up to 75
subjects with mCRPC. Patients are receiving a total of eight doses of drug at
2.5 mg/kg. The study endpoints evaluate responses in prostate specific antigen
(PSA); circulating tumor cells (CTC); pain; and change in tumor size as
measured under RECIST criteria. Safety also is being evaluated.

Phase 1 study design

The phase 1, open-label, dose-escalation clinical trial was conducted in men
with hormone-refractory prostate cancer that had progressed despite prior
treatment with taxane-based chemotherapy regimens. In addition to assessing
PSMA ADC's safety and tolerability, the study included evaluations of
pharmacodynamics, changes in tumor burden, and changes in PSA and CTC values
compared to baseline. PSA is a secreted protein that is distinct from PSMA.

The initial 12-week clinical trial period evaluated up to four intravenous
doses of PSMA ADC administered at three-week intervals. Following completion
of the four doses, patients were offered, at their physicians' discretion, the
option to continue treatment with PSMA ADC for up to an additional 39 weeks.

About PSMA ADC

PSMA, a protein that is a validated biomarker of prostate cancer, is expressed
on the surface of prostate cancer cells as well as on blood vessels supplying
other solid tumors. PSMA ADC comprises a fully human monoclonal antibody
selectively targeting PSMA linked to a chemotherapeutic drug. Using technology
licensed from Seattle Genetics, Inc., the PSMA antibody is linked to
monomethyl auristatin E, a compound that inhibits cell proliferation by
disrupting the cellular "backbone" (i.e., microtubules) required for
replication. The resultant antibody-drug conjugate attaches to the PSMA
protein on the surface of prostate cancer cells and is designed to internalize
into the cancer cell, release active anti-cancer drug, and destroy the
malignant cell.

Unlike traditional chemotherapy, PSMA ADC is designed to deliver the drug
selectively to prostate cancer cells by targeting PSMA. In pre-clinical
studies, PSMA ADC exhibited a high level of tumor-specific activity.

About Prostate Cancer

Prostate cancer is the most common form of cancer affecting men in the United
States and is the second leading cause of cancer deaths among men each year.
The American Cancer Society estimates that in 2013, 238,590 new cases of
prostate cancer will be diagnosed and approximately 29,720 American men will
die from the disease.

About Progenics

Progenics Pharmaceuticals, Inc. is discovering and developing innovative
medicines to treat disease, focusing on cancer and related conditions, with a
pipeline that includes product candidates in preclinical through late-stage
development. Progenics' first commercial product, Relistor^® (methylnaltrexone
bromide) for opioid-induced constipation, is marketed and in further
development by Salix Pharmaceuticals, Ltd. for markets worldwide other than
Japan, where Ono Pharmaceutical Co., Ltd. holds an exclusive license for the
subcutaneous formulation. For additional information, please visit
www.progenics.com.

The Progenics Pharmaceuticals Inc. logo is available at
http://www.globenewswire.com/newsroom/prs/?pkgid=9678

This press release may contain projections and other forward-looking
statements regarding future events. Such statements are predictions only, and
are subject to risks and uncertainties that could cause actual events or
results to differ materially. These risks and uncertainties include, among
others, the cost, timing and results of clinical trials and other development
activities; the unpredictability of the duration and results of regulatory
review of New Drug Applications and Investigational NDAs; market acceptance
for approved products; generic and other competition; the possible impairment
of, inability to obtain and costs of obtaining intellectual property rights;
and possible safety or efficacy concerns, general business, financial and
accounting matters, litigation and other risks. More information concerning
Progenics and such risks and uncertainties is available on its website, and in
its press releases and reports it files with the U.S. Securities and Exchange
Commission. Progenics is providing the information in this press release as of
its date and does not undertake any obligation to update or revise it, whether
as a result of new information, future events or circumstances or otherwise.

Additional information concerning Progenics and its business may be available
in press releases or other public announcements and public filings made after
this release.

(PGNX-C)

CONTACT: Amy Martini
         Corporate Affairs
         (914) 789-2816
         amartini@progenics.com

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