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              CYTOGEN REPORTS SECOND QUARTER 2005 FINANCIAL RESULTS

              R&D Day Scheduled for September 13, 2005 in New York

PRINCETON,  N.J.,  (August 4, 2005) -- Cytogen  Corporation  (Nasdaq:  CYTO),  a
product-driven   biopharmaceutical  company,  today  reported  its  consolidated
financial results for the second quarter and six months ended June 30, 2005.

FINANCIAL HIGHLIGHTS
- --------------------

  o  Sales of  QUADRAMET(R)  (samarium  Sm-153  lexidronam  injection) were $2.2
     million for the second quarter ended June 30, 2005 compared to $1.6 million
     for  the  same   quarter  of  2004,   representing   33%   revenue   growth
     year-over-year.  For the six months ended June 30, 2005, sales of QUADRAMET
     were $4.2  million  compared  to $3.5  million in the same  period of 2004,
     representing 21% revenue growth year-over-year.

  o  Sales of PROSTASCINT(R) (capromab pendetide) kits were $1.9 million for the
     second  quarter  ended June 30, 2005  compared to $2.3 million for the same
     quarter  in  2004.  For the six  months  ended  June  30,  2005,  sales  of
     PROSTASCINT  were $3.8 million  compared to $4.0 million in the same period
     of 2004.  The  decrease  from the prior year  periods is  primarily  due to
     changes in distributor  buying patterns  evidenced in the second quarter of
     2004.

  o  Total  product  revenues  for the second  quarter of 2005 were $4.1 million
     compared to $3.9 million in the second  quarter of 2004. For the six months
     ended June 30, 2005,  total product  revenues were $8.0 million compared to
     $7.5 million in the same period of 2004.

  o  Average gross margin for the six months ended June 30, 2005 improved to 43%
     compared to 37% for the same period in 2004.

  o  Cytogen reported a net loss of $7.7 million, or $0.50 per basic and diluted
     share in the second quarter of 2005, compared to $4.4 million, or $0.30 per
     basic and diluted  share,  for the same period in 2004.  For the six months
     ended June 30, 2005,  total net loss was $14.3 million,  or $0.92 per basic
     and diluted share, compared to $8.7 million, or $0.63 per basic and diluted
     share,  in the  same  period  of 2004.  The  increase  in net loss  results
     primarily  from  the  implementation  of  new  marketing   initiatives  and
     expansion of the Company's sales force,  which was substantially  completed
     in January 2005.

"The expansion of our sales force and marketing  programs  during the first half
of 2005 and our efforts to extend our product  lines through  targeted  clinical
development  initiatives will be important  contributors to our future success,"
said Michael D. Becker,  Cytogen's  president and chief executive  officer.  "We
have hired great people  throughout  the ranks and our  customers  are giving us
positive feedback on our products and pipeline. As a commercial organization,  I
believe  we are  better  positioned  today  than  ever  and are  excited  by our
prospects for growth in the second half of 2005 and beyond."






PRODUCT REVENUE
- ---------------

QUADRAMET

QUADRAMET is Cytogen's flagship product for the relief of pain due to metastatic
bone disease arising from prostate,  breast, multiple myeloma and other types of
cancer. Sales of QUADRAMET were $2.2 million for the quarter ended June 30, 2005
compared to $1.6 million for the same period in 2004,  representing  33% revenue
growth  year-over-year.  For the six  months  ended  June  30,  2005,  sales  of
QUADRAMET were $4.2 million compared to $3.5 million in the same period of 2004,
representing 21% revenue growth year-over-year.

                       QUADRAMET QUARTERLY REVENUE SUMMARY
                                ($'s in millions)

                 2004       2004      2004      2004     |   2005      2005
                  Q1         Q2        Q3        Q4      |    Q1        Q2
                 ----       ----      ----      ----         ----      ----

Product Sales    $1.9       $1.6      $1.9      $1.9     |   $2.1      $2.2


PROSTASCINT

Sales of  PROSTASCINT  kits  (for the  preparation  of  Indium  In-111  capromab
pendetide),  the first and only commercial monoclonal  antibody-based agent that
targets prostate-specific membrane antigen (PSMA) to image the extent and spread
of  prostate  cancer,  were $1.9  million  for the  quarter  ended June 30, 2005
compared to $2.3  million in the same period of 2004.  For the six months  ended
June 30, 2005,  sales of PROSTASCINT  were $3.8 million compared to $4.0 million
in the same  period  of 2004.  The  decrease  from the  prior  year  periods  is
primarily due to changes in distributor  buying patterns evidenced in the second
quarter of 2004.

                      PROSTASCINT QUARTERLY REVENUE SUMMARY
                                ($'s in millions)

                 2004       2004      2004      2004     |   2005      2005
                  Q1         Q2        Q3        Q4      |    Q1        Q2
                 ----       ----      ----      ----         ----      ----

Product Sales    $1.7       $2.3      $1.3      $1.8     |   $1.9      $1.9

"Our  strategy  for  increasing  product  sales is  centered  on key  drivers of
long-term  growth  for both  QUADRAMET  and  PROSTASCINT,"  said  Thomas  Lytle,
Cytogen's  senior vice president of sales and marketing.  "For QUADRAMET,  these
include:   (i)  distinguishing   the  physical   properties  of  QUADRAMET  from
first-generation  agents within its class,  (ii) empowering and marketing to key
prescribing  audiences,  (iii)  broadening  palliative  use within  label beyond
prostate cancer to include breast,  lung, multiple myeloma,  (iv) evaluating the
role of QUADRAMET in combination with other commonly used oncology  agents,  and
(v) expanding  clinical  development  to demonstrate  the potential  tumoricidal
versus  palliative  attributes  of  QUADRAMET.  For  PROSTASCINT,  these drivers
include: (i) improving image quality through fusion technology,  (ii) validating
the antigen targeted by PROSTASCINT as an independent  prognostic factor,  (iii)
the  publication  and   presentation  of  outcomes  data,  (iv)  development  of
image-guided applications including brachytherapy, intensity modulated radiation
therapy,  surgery,  and cryotherapy,  and (v) expanding clinical  development to
demonstrate the potential for PROSTASCINT to both monitor  response to cytotoxic
therapies and image PSMA expression in other cancers. We believe we now have the
resources,  talent and unique opportunity to maximize the potential of these two
important products."





COSTS AND EXPENSES
- ------------------

TOTAL OPERATING EXPENSES

Total operating  expenses for the quarter ended June 30, 2005 were $12.0 million
compared to $8.4  million for the same period in 2004.  For the six months ended
June 30, 2005,  total  operating  expenses were $22.7 million  compared to $16.3
million in the same period of 2004.

COST OF PRODUCT REVENUE

Cost of product revenue for the second quarters ended June 30, 2005 and June 30,
2004 were $2.3 million and $2.4 million,  respectively. For the six months ended
June 30, 2005, cost of product revenue was $4.7 million compared to $4.8 million
in the same period of 2004,  and primarily  reflects  QUADRAMET and  PROSTASCINT
manufacturing  costs,  royalties paid by Cytogen on the Company's product sales,
and the  amortization  of the  up-front  payment  to  Berlex  to  reacquire  the
marketing rights to QUADRAMET.

SG&A EXPENSES

Selling, general and administrative expenses for the quarter ended June 30, 2005
were $6.7 million  compared to $4.9 million for the same period in 2004. For the
six months  ended June 30,  2005,  total  selling,  general  and  administrative
expenses were $13.7 million compared to $8.8 million in the same period of 2004.
The increase in selling, general and administrative expenses is primarily driven
by  expanded  investment  for  the  commercial  support  of both  QUADRAMET  and
PROSTASCINT,  including  the  implementation  of new marketing  initiatives  and
expansion of the Company's  sales force,  which was  substantially  completed in
January 2005.

R&D EXPENSES

Research and development  expenses for the quarter ended June 30, 2005 were $1.4
million  compared  to $541,000  for the same period in 2004.  For the six months
ended June 30, 2005, total internal research and development  expenses were $2.1
million  compared to $1.3  million in the same period of 2004.  The  increase in
research  and  development   expenses  is  primarily   driven  by  new  clinical
development initiatives for both QUADRAMET and PROSTASCINT and a $500,000 charge
in the second quarter of 2005 for a non-cash  milestone  payment  related to the
progress of PSMA  development  programs.  In addition,  research and development
expenses  include  preclinical  development  costs associated with the Company's
recently announced program to attach the therapeutic  radionuclide  lutetium-177
as a payload to the 7E11.C5.3 monoclonal antibody utilized in PROSTASCINT.

EQUITY IN LOSS OF JOINT VENTURE

Joint venture  research and development  expenses  reflect costs associated with
the PSMA  Development  Company LLC ("PDC"),  a joint venture between Cytogen and
Progenics Pharmaceuticals,  Inc., for the development of in vivo immunotherapies
targeting PSMA.  Cytogen's share of the equity in the loss of PDC for the second
quarter and six months ended June 30, 2005 were $1.7  million and $2.2  million,
respectively,  compared  to  $542,000  and $1.4  million,  respectively,  in the
comparable  periods in 2004.  The increase  over prior year periods is primarily
due to  Cytogen's  share of the $2.0  million  upfront  fee  incurred  by PDC to
license  proprietary  antibody-drug  conjugate  (ADC)  technology  from  Seattle
Genetics,  Inc. for use with PDC's  antibodies  targeting  PSMA,  as  previously
communicated on June 20, 2005.

INVENTORIES

Inventories as of June 30, 2005 were $5.1 million compared to $3.6 million as of
December 31, 2004.  The increase in  inventories is due primarily to the current
manufacturing runs of PROSTASCINT. In September





2004, Cytogen entered into a manufacturing  agreement with Laureate Pharma, L.P.
pursuant  to which  Laureate  is  manufacturing  PROSTASCINT  for Cytogen in its
Princeton,  NJ facility.  Cytogen  believes  that the  agreement  will provide a
sufficient  supply  of  PROSTASCINT  to  satisfy  commercial   requirements  for
approximately the next four years, based upon current sales levels. In addition,
Cytogen  believes  that the  agreement  will  provide  sufficient  supply of the
7E11.C5.3  monoclonal antibody required for initial clinical  development of the
Company's therapeutic program.

CASH POSITION
- -------------

Cytogen's cash, cash equivalents and short-term  investments  balance as of June
30, 2005 was $20.5  million  compared to $35.8  million as of December 31, 2004.
This June 30, 2005 balance does not reflect approximately $14.0 million in gross
proceeds  from the July 2005 sale of common  stock and  warrants,  which  closed
during the third quarter of 2005.

SECOND QUARTER PRODUCT AND PIPELINE HIGHLIGHTS
- ----------------------------------------------

QUADRAMET

  o  The  publication  of new  data  from a  phase  II  study  of  QUADRAMET  in
     combination with docetaxel (Taxotere(R),  Aventis Pharmaceuticals, a member
     of the  sanofi-aventis  Group) for the  treatment of patients  with hormone
     refractory   prostate  cancer.  The  published  abstract  is  part  of  the
     proceedings at the 2005 American Society of Clinical Oncology (ASCO) Annual
     Meeting  and  the  lead  investigator  was  Anders  Widmark,  M.D.,  Ph.D.,
     professor,   department  of  oncology,  Umea  University,   Sweden.
  o  The  presentation  of a new clinical study  evaluating the use of high dose
     QUADRAMET  in   conjunction   with   gemcitabine   for  the   treatment  of
     osteosarcoma.  The data was presented  during the 2005 ASCO Annual  Meeting
     and the lead  investigator  was Peter  Anderson,  M.D.,  Ph.D., a pediatric
     oncologist  who  performed  the work at the Mayo  Clinic  and is now at The
     University of Texas MD Anderson  Cancer  Center,  another  center active in
     studies using  QUADRAMET.
  o  The presentation of data from studies in which patients  received  multiple
     doses of  QUADRAMET.  The data were  presented  during the 2005 ASCO Annual
     Meeting and the lead author was Oliver Sartor,  M.D., a medical  oncologist
     who is  director  of  the  Stanley  S.  Scott  Cancer  of  Louisiana  State
     University Health Sciences Center in New Orleans.
  o  The presentation of new data  demonstrating  the use of QUADRAMET alone and
     in conjunction  with  chemotherapy  for the treatment of prostate,  breast,
     lung,  and other  cancers.  The abstracts  were  presented  during the 2005
     Society of Nuclear  Medicine  (SNM)  Annual  Meeting  and were  reported by
     independent investigators.

PROSTASCINT

  o  The  presentation  of outcome data  obtained  over a  seven-year  follow-up
     period  demonstrating that PROSTASCINT imaging both increased  disease-free
     survival rates and independently predicted a three-fold increase in risk of
     recurrent  disease in prostate cancer patients  following  definitive local
     therapy.  The study was presented  during the 26th  American  Brachytherapy
     Society (ABS) Annual Meeting and was carried out by investigators from Case
     Western Reserve  University,  University  Hospital of Cleveland and Aultman
     Hospital  in  Canton,  Ohio and was led by Rodney  Ellis,  M.D.,  radiation
     oncologist at Aultman  Hospital and assistant  professor of urology at Case
     Western Reserve University School of Medicine.





PSMA

  o  Cytogen and Dowpharma(SM) contract manufacturing  services, a business unit
     of The Dow Chemical Company, announced a collaboration to create a targeted
     oncology  product  designed to treat prostate and other cancers.  Under the
     agreement, Dowpharma's proprietary MeO-DOTA bifunctional chelant technology
     will be used to radiolabel Cytogen's 7E11.C5.3 monoclonal antibody with the
     therapeutic radionuclide lutetium-177. Cytogen recently completed the scale
     up and  manufacture of the  toxicology  lot for this product  candidate and
     preclinical  toxicology  studies are  scheduled  to begin  during the third
     quarter  of 2005 in  advance  of filing an  investigational  new drug (IND)
     application  for the  treatment of prostate  cancer in the first quarter of
     2006.
  o  Seattle  Genetics  licensed its proprietary  antibody-drug  conjugate (ADC)
     technology to PDC. The license  provides PDC with rights to utilize the ADC
     technology  to  link  cell-killing  drug  payloads  to  PDC's  fully  human
     monoclonal antibodies that target PSMA.

FINANCIAL OUTLOOK FOR 2005
- --------------------------

This section  provides  forward-looking  information  about Cytogen's  financial
outlook  for 2005 based  upon our  current  operations.  The  disclosure  notice
paragraph regarding  forward-looking  statements at the end of this news release
is especially applicable to this section.

Cytogen today  commented on its financial  outlook for the year ending  December
31, 2005. The Company  continues to believe,  based on current  business trends,
that total revenue for the year will be within the guidance of approximately $20
to $25 million  previously  provided on May 5, 2005,  but at the low end of that
range.   Average  gross  margin  is  expected  to  be  within  the  guidance  of
approximately  40% to 50%.  Selling,  general and  administrative  expenses  are
expected to be within the guidance of  approximately  $25 to $30 million.  Total
internal and  external  joint  venture  research  and  development  expenses are
expected to be within the guidance of approximately $10 to $15 million.

UPCOMING EVENTS
- ---------------

Cytogen expects to discuss its current and future  clinical  programs during its
Research &  Development  (R&D) Day on Tuesday,  September  13, 2005, in New York
City.

CONFERENCE CALL & WEBCAST INFORMATION
- -------------------------------------

Cytogen will  broadcast its  quarterly  investor  conference  call live over the
Internet today,  August 4, 2005 at 9:00 a.m.  Eastern Standard Time. The dial-in
number for the U.S. is 1-800-299-9086 and the pass code number is 62921717.  The
dial-in number for  international  callers is  1-617-786-2903  and the pass code
number is 62921717.  This event can also be accessed by going to  Cytogen's  Web
site, www.cytogen.com,  and clicking on the "Investor Relations" link. A link to
the webcast is under the Calendar of Events  header.  The event will be archived
and  available  for replay  starting  approximately  one hour after the call and
continuing  for 7 days  thereafter.  The replay  dial-in  number for the U.S. is
888-286-8010 and the dial-in number for  international  callers is 617-801-6888.
The replay pass code number is 18186782.

NOTE:
- -----

QUADRAMET  is  indicated  for the  relief  of pain in  patients  with  confirmed
osteoblastic  metastatic  bone lesions that enhance on  radionuclide  bone scan.
This  press  release  describes  clinical  applications  that  differ  from that
reported in the QUADRAMET package insert.

PROSTASCINT  is  indicated  as a  diagnostic  imaging  agent in newly  diagnosed
patients with biopsy-proven  prostate cancer, thought to be clinically localized
after standard diagnostic evaluation and who are thought to be





at high risk for pelvic lymph node metastases.  PROSTASCINT is also indicated as
a diagnostic imaging agent in post-prostatectomy  patients with a rising PSA and
a negative or equivocal standard  metastatic  evaluation in whom there is a high
clinical  suspicion of occult metastatic  disease.  This press release describes
clinical applications and imaging performance that differs from that reported in
the PROSTASCINT package insert.

A copy of the full prescribing  information for QUADRAMET and PROSTASCINT may be
obtained in the U.S. from Cytogen  Corporation by calling toll free 800-833-3533
or by visiting the web site at www.cytogen.com,  which is not part of this press
release.

ABOUT CYTOGEN CORPORATION
- -------------------------

Founded  in 1980,  Cytogen  Corporation  of  Princeton,  NJ is a  product-driven
biopharmaceutical  company that 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.

                                       ###





                       CYTOGEN CORPORATION & SUBSIDIARIES
                (All amounts in thousands except per share data)
                                   (Unaudited)

                 CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS




                                                          THREE MONTHS ENDED               SIX MONTHS ENDED
                                                               JUNE 30,                         JUNE 30,
                                                          ------------------               ----------------
                                                           2005        2004                 2005      2004
                                                          ------      ------               ------    ------
                                                                                         
Product Revenue:
     QUADRAMET                                            $  2,153    $ 1,616              $  4,207  $  3,470
     PROSTASCINT                                             1,924      2,312                 3,823     4,039
     Others                                                      -          -                     -         1
                                                          --------    -------              --------  --------
          Total Product Revenue                              4,077      3,928                 8,030     7,510

License and Contract Revenue                                    79         24                   120        43
                                                          --------    -------              --------  --------
          Total Revenues                                     4,156      3,952                 8,150     7,553
                                                          --------    -------              --------  --------

Operating Expenses:
     Cost of Product Revenue                                 2,251      2,396                 4,678     4,795
     Selling, General and Administrative                     6,692      4,914                13,716     8,805
     Research and Development                                1,362        541                 2,101     1,345
     Equity in Loss of Joint Venture                         1,704        542                 2,202     1,351
                                                          --------    -------              --------  --------
          Total Operating Expenses                          12,009      8,393                22,697    16,296
                                                          --------    -------              --------  --------

Interest Income, Net                                           112         57                   213        77
                                                          --------    -------              --------  --------
Net Loss                                                  $ (7,741)   $(4,384)             $(14,334) $ (8,666)
                                                          ========    =======              ========  ========

Basic and Diluted Net Loss Per Share                      $  (0.50)   $ (0.30)             $  (0.92) $  (0.63)
                                                          ========    =======              ========  ========

Weighted Average Common Shares Outstanding                  15,525     14,848                15,519    13,859
                                                          ========    =======              ========  ========




                      CONDENSED CONSOLIDATED BALANCE SHEETS



                                                                      JUNE 30,       DECEMBER 31,
                                                                       2005              2004
                                                               -----------------  ----------------
                                                                              
Assets:
     Cash, Cash Equivalents and Short-Term Investments            $     20,532      $     35,825
     Accounts Receivable, Net                                            1,821             1,406
     Inventories                                                         5,103             3,623
     Property and Equipment, Net                                           801               787
     QUADRAMET License Fee, Net                                          6,675             7,024
     Other Assets                                                        1,108             1,748
                                                                  ------------      ------------
           Total Assets                                           $     36,040      $     50,413
                                                                  ============      ============

Liabilities and Stockholders' Equity:
     Accounts Payable and Accrued Liabilities                     $      6,130      $      7,644
     Other Current Liabilities                                           3,398             2,692
     Long-Term Liabilities                                                  38                47
     Stockholders' Equity                                               26,474            40,030
                                                                  ------------      ------------
           Total Liabilities and Stockholders' Equity             $     36,040      $     50,413
                                                                  ============      ============