MEDIA/INVESTORS CONTACT:
Jonathan Fassberg
The Trout Group
(212) 477-9077 x16

               CYTOGEN CORPORATION UPDATES 2005 FINANCIAL GUIDANCE

PRINCETON,  N.J.,  (OCTOBER 4, 2005) -- Cytogen  Corporation  (Nasdaq:  CYTO), a
product-driven  biopharmaceutical  company, today updated its financial guidance
for the year ending December 31, 2005.

During the third quarter of 2005,  Cytogen  recorded total product sales of $3.5
million,  representing an 8% increase over sales in the same period of 2004, but
below the  company's  internal  expectations.  Total  product sales for the nine
month  period  ended  September  30, 2005 were $11.5  million  compared to $10.7
million for the same period in 2004,  representing an increase of 7%. Cytogen is
withdrawing  previously  provided  revenue guidance for the year ending December
31, 2005, as the company currently anticipates that actual results will be lower
than its previous guidance of approximately $20 million.

Average gross margin is expected to be within the company's previous guidance of
approximately  40% to 50%.  Selling,  general and  administrative  expenses  are
expected to be within the company's  previous  guidance of approximately  $25 to
$30 million.  Total internal and external joint venture research and development
expenses  are  expected  to  be  within  the  company's   previous  guidance  of
approximately $10 to $15 million.

Cytogen  believes the  fundamentals  of its  business  and clinical  development
pipeline remain strong and that revenue growth will require continued efforts to
expand awareness and use of the company's oncology products,  the publication of
data from ongoing clinical trials that demonstrate the role of these products in
contemporary  oncology  settings,  and the introduction of new models to improve
patient access to radiopharmaceuticals.

Cytogen will report third quarter financial results on Tuesday, November 8, 2005
before the  financial  markets  open.  The  announcement  will be  followed by a
conference call with the investment community at 9:00 a.m. EST.

ABOUT CYTOGEN CORPORATION
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Founded  in 1980,  Cytogen  Corporation  of  Princeton,  NJ is a  product-driven
biopharmaceutical company that acquires,  develops and commercializes innovative
molecules  that  can be used to build  leading  franchises.  Cytogen's  marketed
products  include  QUADRAMET(R)   (samarium  Sm-153  lexidronam  injection)  and
PROSTASCINT(R)  (capromab  pendetide)  kit for the  preparation of Indium In-111
capromab  pendetide  in the United  States.  Cytogen also has  exclusive  United
States marketing rights to COMBIDEX(R)  (ferumoxtran-10)  for all  applications,
and the exclusive right to market and sell  ferumoxytol  (previously  Code 7228)
for oncology  applications in the United States.  Cytogen's development pipeline
consists of therapeutics targeting  prostate-specific membrane antigen (PSMA), a
protein  highly  expressed  on the  surface  of  prostate  cancer  cells and the
neovasculature of solid tumors.  Full prescribing  information for the Company's
products is available at www.cytogen.com or by calling 1-800-833-3533.  For more
information, please visit the Company's website at www.cytogen.com, which is not
part of this press release.



This press release  contains  certain  "forward-looking"  statements  within the
meaning of the Private Securities  Litigation Reform Act of 1995 and Section 21E
of the Securities Exchange Act of 1934, as amended.  All statements,  other than
statements of  historical  facts,  included in this press release  regarding our
strategy, future




operations,  financial position,  future revenues,  projected costs,  prospects,
plans  and  objectives  of  management  are  forward-looking   statements.  Such
forward-looking  statements  involve  a number of risks  and  uncertainties  and
investors  are cautioned  not to put any undue  reliance on any  forward-looking
statement.  There are a number of important  factors that could cause  Cytogen's
results  to differ  materially  from  those  indicated  by such  forward-looking
statements.  In  particular,  Cytogen's  business  is  subject  to a  number  of
significant risks, which include,  but are not limited to: the risk of obtaining
the necessary  regulatory  approvals;  the risk of whether  products result from
development  activities;  the  risk  of  shifts  in the  regulatory  environment
affecting sales of Cytogen's  products such as third-party  payor  reimbursement
issues;  the risk  associated  with  Cytogen's  dependence  on its  partners for
development of certain projects, as well as other factors expressed from time to
time in Cytogen's  periodic filings with the Securities and Exchange  Commission
(the "SEC"). As a result,  this press release should be read in conjunction with
Cytogen's  periodic  filings  with  the  SEC.  The  forward-looking   statements
contained herein are made only as of the date of this press release, and Cytogen
undertakes no obligation to publicly update such  forward-looking  statements to
reflect subsequent events or circumstances.

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