As filed with the Securities and Exchange Commission on October 24, 2003
                                                    Registration No. 333-

--------------------------------------------------------------------------------

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                               ---------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                               CYTOGEN CORPORATION
--------------------------------------------------------------------------------
             (Exact Name of Registrant as Specified in its Charter)


                               650 College Road East, Suite
         Delaware           3100, Princeton, New Jersey 08540     22-2322400
-----------------------    ----------------------------------  -----------------
   (State or Other              (Address of Principal          (I.R.S. Employer
   Jurisdiction of              Executive Offices)             Identification
   Incorporation or                 (Zip Code)                       No.)
   Organization)


                       1995 Stock Option Plan, as amended
                          January 2001 Option Agreement
--------------------------------------------------------------------------------
                            (Full Title of the Plans)


                            Donald L. Novajosky, Esq.
                                 Director, Legal
                               Cytogen Corporation
                        650 College Road East, Suite 3100
                           Princeton, New Jersey 08540
--------------------------------------------------------------------------------
                              (Name and Address of
                               Agent for Service)


                                 (609) 750-8222
--------------------------------------------------------------------------------
                     (Telephone Number, Including Area Code,
                              of Agent For Service)

                                    Copy To:

                           Richard S. Mattessich, Esq.
                                Hale and Dorr LLP
                              650 College Road East
                               Princeton, NJ 08540
                                 (609) 750-7600


<PAGE>


<TABLE>
<CAPTION>
                         CALCULATION OF REGISTRATION FEE

=========================================================================================
                                                  Proposed
                                                  Maximum       Proposed
                                        Amount    Offering       Maximum      Amount Of
         Title Of Securities             To Be    Price Per     Aggregate    Registration
          To Be Registered            Registered    Share    Offering Price      Fee
                                          (1)
-----------------------------------------------------------------------------------------
Common Stock, par value $.01 per
share:
<S>                                      <C>        <C>        <C>             <C>
  Shares to be issued pursuant to        46,319     $10.37(2)  $  480,328(2)   $ 38.86
     prior option grants under the
     1995 Stock Option
     Plan..........................
  Shares to be issued pursuant to
     future option grants under the
     1995 Stock Option
     Plan..........................     153,681     $11.27(3)  $1,731,985(3)   $140.12
  Shares to be issued pursuant to
     prior option grants under the
     January 2001 Option Agreement.       1,000     $61.255(4) $   61,255(4)   $  4.96
-----------------------------------------------------------------------------------------
     TOTAL.........................     201,000                $2,273,568      $183.93
=========================================================================================
</TABLE>


(1)   For the sole purpose of calculating  the  registration  fee, the number of
      shares to be registered under this Registration Statement has been divided
      among three (3) subtotals.

(2)   Pursuant to Rule 457(h),  these prices are calculated  based on a weighted
      average  exercise price of $10.37 per share covering 46,319 shares subject
      to stock options granted under the 1995 Stock Option Plan.

(3)   Pursuant to Rule 457(h) and Rule 457(c), these prices are estimated solely
      for the purpose of calculating the registration fee and are based upon the
      average of the high and low prices of the  Company's  Common  Stock on the
      Nasdaq National Market on October 22, 2003.

(4)   Pursuant to Rule 457(h), these prices are calculated based on the exercise
      price of $61.255 per share  covering 1,000 shares subject to stock options
      granted under the January 2001 Option Agreement.

      In addition,  pursuant to Rule 416 under the  Securities  Act of 1933,  as
amended,  this  Registration  Statement also covers an  indeterminate  number of
shares as may be issued as a result of the anti-dilution and similar  provisions
of the 1995 Stock Option Plan and the January 2001 Option Agreement.

                                 ---------------



                                       ii

<PAGE>


                                 Explanatory Note

      The documents containing the information  specified in the instructions to
Part I of Form S-8 will be sent or given to participants of Cytogen's 1995 Stock
Option Plan, as amended,  as required by Rule 428(b)(1) of the Securities Act of
1933. As permitted by the  instructions  to Part I of Form S-8, these  documents
are not filed with this registration statement.  Pursuant to General Instruction
E of Form  S-8,  Cytogen  hereby  incorporates  by  reference  the  Registration
Statement on Form S-8 previously filed by the Registrant with the Securities and
Exchange  Commission  on October  10, 1995 (File No.  033-63321),  as amended by
filings on May 29, 1996 (File No.  333-04679)  and on October 18, 2000 (File No.
333-27673) in connection with the 1995 Stock Option Plan.

      This  registration  statement  contains a reoffer  prospectus  prepared in
accordance  with the  requirements of Part I of Form S-3 with respect to options
to purchase 1,000 shares of Common Stock granted to an affiliate pursuant to the
January  2001  Option  Agreement.  Such  individual  is  listed  on the  Selling
Shareholder Table herein.

      This  registration  statement also contains  "Information  Required in the
Registration  Statement" prepared in accordance with the requirements of Part II
of Form S-8 with respect to options to purchase  200,000  shares of Common Stock
granted  pursuant to Cytogen's 1995 Stock Option Plan, as amended,  prior to the
date hereof, and that may be granted subsequent to the date hereof. Such 200,000
shares of Common Stock relate to a previously approved increase in the number of
shares of Common Stock  authorized  for issuance upon the exercise of options to
be granted under Cytogen's 1995 Stock Option Plan.



                                      iii

<PAGE>


                                   PROSPECTUS

                  S-3 Reoffer Prospectus dated October 24, 2003

                               CYTOGEN CORPORATION

                          1,000 Shares of Common Stock
                Issuable under the January 2001 Option Agreement


      This  Prospectus  relates to the public  resale,  from time to time, of an
aggregate of 1,000 shares (the  "Shares")  of our Common  Stock,  $.01 par value
(the "Common Stock") by that certain shareholder identified below in the section
entitled  "The  Selling  Shareholder."  These  Shares may be  acquired  upon the
exercise of stock options granted outside of any of our option plans.

      We will not  receive  any of the  proceeds  from  the sale by the  Selling
Shareholder of the Shares covered by this Prospectus.

      We have not entered into any underwriting  arrangements in connection with
the sale of  Shares.  The  Shares  may be sold from time to time by the  Selling
Shareholder or by permitted  pledgees,  donees,  transferees or other  permitted
successors in interest and may be made on the Nasdaq  National  Market at prices
and at terms then  prevailing  or at prices  related to the then current  market
price, or in negotiated transactions.

      Our Common Stock is traded on the Nasdaq  National Market under the symbol
"CYTO." On October 22,  2003,  the closing sale price of our Common Stock on the
Nasdaq National Market was $11.16 per share.

      INVESTING  IN THE COMMON STOCK  INVOLVES A HIGH DEGREE OF RISK.  SEE "RISK
FACTORS" BEGINNING ON PAGE 5.

      NEITHER THE  SECURITIES AND EXCHANGE  COMMISSION NOR ANY STATE  SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS  IS TRUTHFUL OR  COMPLETE.  ANY  REPRESENTATION  TO THE CONTRARY IS A
CRIMINAL OFFENSE.

                The date of this Prospectus is October 24, 2003.


<PAGE>


                                TABLE OF CONTENTS
--------------------------------------------------------------------------------
Cytogen Corporation....................................................     3
Reverse Stock Split....................................................     4
Risk Factors...........................................................     5
      We  have a  history  of  operating  losses  and an  accumulated
        deficit and expect to incur losses in the future...............     5
      We  depend  on  sales  of  ProstaScint  and  Quadramet  for the
        majority of our near-term revenues.............................     6
      We  depend  on  acceptance  of  our  products  by  the  medical
        community for the continuation of our revenues.................     6
      The reduced  workforce  at AxCell may not be able to  implement
        AxCell's business plan.........................................     7
      We may  need to  raise  additional  capital,  which  may not be
        available......................................................     7
      Our capital raising efforts may dilute stockholder interests.....     8
      We may need to raise funds other than  through the  issuance of
        equity securities..............................................     8
      Our   products,   generally,   are  in  the  early   stages  of
        development  and  commercialization  and we may never achieve
        the revenue goals set forth in our business plan...............     8
      Our  PSMA   product   development   program   is   novel   and,
        consequently, inherently risky.................................     9
      All of our potential  oncology  products will be subject to the
        risks of failure  inherent in the  development  of diagnostic
        or therapeutic products based on new technologies..............     9
      Competition in our field is intense and likely to increase.......    10
      We rely heavily on our collaborative partners....................    11
      Our business  could be harmed if certain  agreements  expire or
        are terminated early...........................................    12
      We have limited sales, marketing and distribution  capabilities
        for our products...............................................    13
      There are risks  associated  with the manufacture and supply of
        our products...................................................    14
      Failure of  consumers  to obtain  adequate  reimbursement  from
        third-party  payors could limit market  acceptance and affect
        pricing of our products........................................    14
      If  we  are  unable  to  comply  with  applicable  governmental
        regulation we may not be able to continue our operations.......    15
      We could be  negatively  impacted by future  interpretation  or
        implementation  of federal  and state  fraud and abuse  laws,
        including  anti-kickback  laws,  the  Federal  Stark  Law and
        other federal and state anti-referral laws.....................    16
      We depend on attracting and retaining key personnel..............    17
      Our business exposes us to potential  liability claims that may
        exceed  our  financial  resources,  including  our  insurance
        coverage,  and may lead to the  curtailment or termination of
        our operations.................................................    18
      Our business  involves  environmental  risks that may result in
        liability......................................................    18
      Our intellectual property is difficult to protect................    19
      Our   security   measures   may  not  protect  our   unpatented
        proprietary technology.........................................    20
      We are currently subject to patent litigation....................    20
      Our stock price has been and may continue to be  volatile,  and
        your  investment  in our  stock  could  decline  in  value or
        fluctuate significantly........................................    21
--------------------------------------------------------------------------------



                                      - i -

<PAGE>


                                TABLE OF CONTENTS
--------------------------------------------------------------------------------
      We have  adopted  various  anti-takeover  provisions  which may
        affect the market  price of our common  stock and  prevent or
        frustrate  attempts by our  stockholders to replace or remove
        our management team............................................    22
      The  liquidity of our common stock could be adversely  affected
        if we are delisted from The Nasdaq National Market.............    22
      A large  number of our shares  are  eligible  for  future  sale
        which may  adversely  impact the  market  price of our common
        stock..........................................................    23
      Because  we do not intend to pay,  and have not paid,  any cash
        dividends  on our shares of common  stock,  our  stockholders
        will not be able to receive a return on their  shares  unless
        the value of our shares appreciates and they sell them.........    24
Special Note Regarding Forward-Looking Statements......................    25
Use of Proceeds........................................................    25
Selling Shareholder....................................................    26
Plan of Distribution...................................................    27
Legal Matters..........................................................    28
Experts................................................................    28
Where You Can Find More Information....................................    28
Information Incorporated By Reference..................................    29
Indemnification of Officers and Directors..............................    30
--------------------------------------------------------------------------------



                                     - ii -

<PAGE>


                               CYTOGEN CORPORATION

      Cytogen     Corporation    is    a    product-driven,     oncology-focused
biopharmaceutical  company  with an  established  and  growing  product  line in
prostate cancer and other areas of oncology.  Our FDA-approved  products include
ProstaScint(R)  (a  monoclonal  antibody-based  imaging  agent used to image the
extent  and  spread of  prostate  cancer);  Quadramet(R)  (a  therapeutic  agent
marketed  for the relief of bone pain in prostate and other types of cancer) and
NMP22  BladderChek(TM)  (a  point-of-care,  in vitro diagnostic test for bladder
cancer).  Our pipeline is comprised of product  candidates at various  stages of
clinical  development,  including fully human  monoclonal  antibodies and cancer
vaccines based on PSMA prostate  specific membrane antigen  technology,  or PSMA
technologies, which we exclusively licensed from Memorial Sloan-Kettering Cancer
Center.  We also conduct research in cellular  signaling through our subsidiary,
AxCell Biosciences.

      In addition to the products listed above, in August, 2000, we expanded our
product pipeline by entering into marketing,  license and supply agreements with
Advanced Magnetics,  Inc. for Combidex(R),  which is an investigational magnetic
resonance  imaging (MRI) contrast agent that assists in the  differentiation  of
metastatic from  non-metastatic  lymph nodes. We hold exclusive marketing rights
to Combidex in the United  States and its  territories.  Advanced  Magnetics  is
continuing its discussions with the FDA relating to outstanding issues regarding
an approvable  letter received from the FDA in June, 2000, in an effort to bring
Combidex to market.

      We have had a history of operating  losses since our  inception.  We had a
net loss of $3.4 million for the three months ended June 30, 2003, a net loss of
$5.3  million  for the six months  ended  June 30,  2003 and a net loss of $15.7
million for the year ended December 31, 2002.  Although we  continually  look to
expand our product pipeline, we currently rely on two products,  ProstaScint and
Quadramet,  for  substantially all of our revenues.  In addition,  we have, from
time to time, ceased sales of certain products, such as BrachySeed and OncoScint
CR/OV, that we previously believed would generate  significant  revenues for our
business.  Our products are subject to significant  regulatory review by the FDA
and other  federal  and state  agencies,  which  requires  significant  time and
expenditures in seeking product approvals. In addition, we rely on collaborative
partners to a significant  degree to  manufacture  our  products,  to secure raw
materials,  and to provide licensing rights to their proprietary products for us
to sell and market to others.

      We are a Delaware  corporation.  We were incorporated and began operations
in 1980  under  the  name  Hybridex,  Inc.  and  changed  our  name  to  Cytogen
Corporation in April 1980. Our executive offices are located at 650 College Road
East,  Suite 3100,  Princeton,  New Jersey 08540,  our telephone number is (609)
750-8200 and our Internet address is  http://www.cytogen.com  The information on
our Internet website is not incorporated by reference in this prospectus. Unless
the context otherwise requires  references in this prospectus to "Cytogen",  the
"Company,"  "we,"  "us,"  and  "our"  refer  to  Cytogen   Corporation  and  our
subsidiaries.

      ProstaScint(R) and OncoScint(R) are registered United States trademarks of
Cytogen  Corporation.  All  other  trade  names,  trademarks  or  service  marks
appearing in this  Registration  Statement on Form S-3 are the property of their
respective  owners,  and not the property of Cytogen  Corporation  or any of our
subsidiaries. Quadramet(R) is a trademark of The Dow Chemical Company used under
license by Cytogen.



                                     - 3 -

<PAGE>


                               REVERSE STOCK SPLIT

      On October 25, 2002, we received  approval from our stockholders at a duly
called and held special meeting of stockholders to effect a reverse split of our
common stock. Our Board of Directors  thereafter  approved a one-for-ten reverse
split of our outstanding,  issued and authorized  shares of common stock,  which
became effective on October 25, 2002. All numbers set forth in this Registration
Statement  on Form S-3  reflect  the effect of such  one-for-ten  reverse  stock
split.



                                     - 4 -

<PAGE>


                                  RISK FACTORS

      Investing in our common stock  involves a high degree of risk.  You should
carefully consider the risks and uncertainties described below before purchasing
our common stock. If any of the following  risks actually  occur,  our business,
financial  condition or results of operations would likely suffer. In that case,
the trading  price of our common stock could fall,  and you may lose all or part
of the money you paid to buy our common stock.

WE HAVE A HISTORY OF OPERATING  LOSSES AND AN ACCUMULATED  DEFICIT AND EXPECT TO
INCUR LOSSES IN THE FUTURE.

Given the high  level of  research  and  development  and  related  expenditures
associated with our business and our inability to generate  revenues  sufficient
to cover such expenditures,  we have had a history of operating losses since our
inception. We had a net loss of $3.4 million for the three months ended June 30,
2003,  a net loss of $5.3  million for the six months  ended June 30, 2003 and a
net loss of $15.7  million for the year ended  December 31,  2002.  Beginning in
December  2001,  we began to  equally  share the  costs of the PSMA  Development
Company  LLC and we  expect to incur  significant  and  increasing  costs in the
future  to fund  our  share  of the  joint  venture.  We had a net loss of $12.1
million for the year ended December 31, 2001. We had a net loss of $27.3 million
for the year ended  December 31, 2000 which included  non-cash  charges of $13.1
million for the acquisition of product candidate rights and $4.3 million for the
cumulative  effect of an accounting  change following the adoption of Securities
and Exchange Commission Staff Accounting Bulletin No. 101. We had an accumulated
deficit of $361.7 million as of June 30, 2003.

In order  to  develop  and  commercialize  our  technologies,  particularly  our
prostate specific membrane antigen, or PSMA, technology, and expand our oncology
products, we expect to incur significant increases in our expenses over the next
several  years.  As a result,  we will need to generate  significant  additional
revenue to become profitable.

To date,  we have  taken  affirmative  steps to reduce  our  trend of  operating
losses. Such steps include, among other things: (i) the effective monitoring and
management  of  expenses  relating  to  research  and  development,  selling and
marketing,  and other general and administrative  matters; (ii) undergoing steps
to  realign  and  implement  our  focus  as a  product-driven,  oncology-focused
biopharmaceutical  company;  (iii)  the  establishment  and  maintenance  of our
in-house  specialty sales force;  (iv) enhancing our marketed product  portfolio
through marketing alliances and strategic arrangements such as we have done with
the Combidex  product,  which we intend to market if this product is approved by
the FDA; (v) the  reacquisition  of North American and Latin American  marketing
rights to  Quadramet  from  Berlex  Laboratories  in August  2003;  and (vi) the
addition of NMP22 BladderChek to our marketed product portfolio.

Although  we  have  taken  these  affirmative  steps,  we may  never  be able to
successfully implement them, and our ability to generate and sustain significant
additional  revenues  or achieve  profitability  will  depend  upon the  factors
discussed  elsewhere in this "Risk Factors"  section,  as well as numerous other
factors outside of our control, including:

o     development  of  competing  products  that  are more  effective  or less
      costly than ours;

o     our  ability  to  develop  and   commercialize   our  own  products  and
      technologies; and

o     our ability to achieve  increased  sales for our  existing  products and
      sales for any new products.



                                     - 5 -

<PAGE>


As a result, we may never be able to generate or sustain significant  additional
revenue or achieve profitability.

WE  DEPEND  ON  SALES OF  PROSTASCINT  AND  QUADRAMET  FOR THE  MAJORITY  OF OUR
NEAR-TERM REVENUES.

We expect  ProstaScint and Quadramet to account for a significant  percentage of
our product related revenues in the near future. For the year ended December 31,
2002,  revenues from  ProstaScint  and royalties  from  Quadramet  accounted for
approximately 64% and 15%, respectively, of our product related revenues; and in
the six months ended June 30, 2003, revenues from ProstaScint and royalties from
Quadramet accounted for approximately 72% and 20%, respectively,  of our product
related  revenues.  If  ProstaScint  or Quadramet do not achieve  broader market
acceptance,  either because we fail to  effectively  market such products or our
competitors  introduce  competing  products,  we may  not be  able  to  generate
sufficient  revenue to become  profitable.  In 2002, our product related revenue
included revenue from BrachySeed, which accounted for 20% of our product related
revenue.  In  January  2003,  we served  notice of  termination  for each of our
License  and  Distribution   Agreement  and  Product  Manufacturing  and  Supply
Agreement  with  Draximage  with  respect  to  both  the  BrachySeed  I-125  and
BrachySeed  Pd-103  products.  As a result,  effective  January 24, 2003,  we no
longer accept or fill new orders for the BrachySeed products.  In April 2003, we
entered into an agreement  with  Draximage  formally  terminating  each of these
agreements.

Generating  market  acceptance  and sales of our  products  is  difficult,  time
consuming and uncertain.  We launched  ProstaScint in October 1996, Quadramet in
March 1997, OncoScint CR/OV in December 1992, BrachySeed I-125 in February 2001,
BrachySeed Pd-103 in May 2002 and NMP22  BladderChek in November 2002.  Revenues
for  ProstaScint  grew from $55,000 in 1996 to $7.9  million in 2002.  Royalties
from sales of Quadramet  went from $3.3 million in 1997 to $1.8 million in 2002.
Royalties  from sales of Quadramet in the initial years of sales were  supported
by a guaranteed  minimum  revenue  arrangement  with the third party licensor of
Quadramet.  OncoScint CR/OV selling  activity was  discontinued in December 2002
and selling activities for the BrachySeed  products were discontinued in January
2003. NMP22  BladderChek is a relatively new product for us.  Currently,  all of
our  revenues  are  derived  from  sales of  ProstaScint,  Quadramet  and  NMP22
BladderChek products, as well as certain license and contract revenues.

WE DEPEND  ON  ACCEPTANCE  OF OUR  PRODUCTS  BY THE  MEDICAL  COMMUNITY  FOR THE
CONTINUATION OF OUR REVENUES.

Because our marketed  products  contribute  the majority of our product  related
revenues, our business,  financial condition and results of operations depend on
their  acceptance as safe,  effective and  cost-efficient  alternatives to other
available   treatment  and  diagnostic   protocols  by  the  medical  community,
including:

o     health care providers, such as hospitals and physicians; and

o     third-party  payors,  including  Medicare,  Medicaid,  private insurance
      carriers and health maintenance organizations.

Our  customers,   including  technologists  and  physicians,  must  successfully
complete our Partners in  Excellence  Program,  or PIE  Program,  a  proprietary
training program designed to promote the correct  acquisition and interpretation
of  ProstaScint  images.  This  product is  technique  dependent  and requires a
learning commitment by technologists and physicians and their acceptance of this
product as part of their treatment practices. If ProstaScint or Quadramet do not
achieve  broader market  acceptance,  we may not be able to generate  sufficient
revenue to become profitable.



                                     - 6 -

<PAGE>


THE REDUCED  WORKFORCE AT AXCELL MAY NOT BE ABLE TO IMPLEMENT  AXCELL'S BUSINESS
PLAN.

In September 2002, we implemented the  restructuring  of our subsidiary,  AxCell
Biosciences  Corporation,  in an effort to reduce expenses and position  Cytogen
for stronger long-term growth in oncology.  As a result, we reduced our staff at
AxCell by  seventy-five  percent,  suspended  certain  projects  at  AxCell  and
implemented other cost-saving measures.

The technologies under development at AxCell are complex and remain commercially
unproven.  Even if we are able to develop and  commercialize  a product  through
AxCell,  there may be fewer than 100 pharmaceutical  companies and biotechnology
companies that are potential customers for such technology or product.

Although we believe that we have  retained the AxCell  personnel  who are key to
achieving AxCell's goals and implementing its strategies, such reduced workforce
may not be able to implement AxCell's current business plan. The further loss of
any of  AxCell's  personnel  could have a material  adverse  effect on  AxCell's
ability to achieve its goals.

WE MAY NEED TO RAISE ADDITIONAL CAPITAL, WHICH MAY NOT BE AVAILABLE.

Our cash and cash equivalents  were $13.5 million as of June 30, 2003,  compared
to $14.7  million as of December 31, 2002.  We expect that our existing  capital
resources  should be adequate to fund our  operations and  commitments  into the
second half of 2004.

We have  incurred  negative cash flows from  operations  since our inception and
have expended, and expect to continue to expend in the future, substantial funds
based upon the:

o     success of our product commercialization efforts;

o     success  of  any  future   acquisitions  of  complementary   products  and
      technologies we may make;

o     magnitude,  scope and results of our product  development and research and
      development efforts;

o     progress of preclinical studies and clinical trials;

o     progress toward regulatory approval for our products;

o     costs of filing,  prosecuting,  defending and enforcing  patent claims and
      other intellectual property rights;

o     competing technological and market developments; and

o     expansion of strategic alliances for the sale,  marketing and distribution
      of our products.

Our business or operations  may change in a manner that would consume  available
resources more rapidly than anticipated.  We expect that we will have additional
requirements  for debt or equity  capital,  irrespective  of whether and when we
reach  profitability,   for  further  product  development  costs,  product  and
technology  acquisition  costs,  and  working  capital.  To the extent  that the
currently  available  funds and  revenues  are  insufficient  to meet current or
planned operating  requirements,  we will be required to obtain additional funds
through equity or debt financing,  strategic  alliances with corporate  partners
and  others,  or through  other  sources.  These  financial  sources  may not be
available when we need them or they may be available,  but on terms that are not
commercially  acceptable to us. If adequate funds are not  available,  we



                                     - 7 -

<PAGE>


may be required to delay, further scale back or eliminate certain aspects of our
operations or attempt to obtain funds through  arrangements  with  collaborative
partners or others that may  require us to  relinquish  rights to certain of our
technologies,  product  candidates,  products or potential markets.  If adequate
funds are not  available,  our  business,  financial  condition  and  results of
operations will be materially and adversely affected.

OUR CAPITAL RAISING EFFORTS MAY DILUTE STOCKHOLDER INTERESTS.

If we raise additional capital by issuing equity  securities,  the issuance will
result in ownership  dilution to our existing  stockholders.  The extent of such
dilution will vary based upon the amount of capital raised.

WE MAY NEED TO RAISE FUNDS OTHER THAN THROUGH THE ISSUANCE OF EQUITY SECURITIES.

If we raise additional funds through collaborations and licensing  arrangements,
we may be  required  to  relinquish  rights to  certain of our  technologies  or
product  candidates or to grant licenses on unfavorable  terms. If we relinquish
rights or grant licenses on unfavorable  terms, we may not be able to develop or
market products in a manner that is profitable to us.

OUR  PRODUCTS,   GENERALLY,   ARE  IN  THE  EARLY  STAGES  OF  DEVELOPMENT   AND
COMMERCIALIZATION  AND WE MAY NEVER  ACHIEVE THE REVENUE  GOALS SET FORTH IN OUR
BUSINESS PLAN.

We began operations in 1980 and have been engaged primarily in research directed
toward the development,  commercialization  and marketing of products to improve
diagnosis  and  treatment of cancer and other  diseases.  In December  1992,  we
introduced  OncoScint CR/OV, and subsequently  ceased selling and marketing this
product in December  2002. In October 1996, we introduced for commercial use our
ProstaScint  imaging agent.  In March 1997, we introduced for commercial use our
Quadramet  therapeutic  product.  In 2001,  we  launched  the iodine  version of
BrachySeed.  In May 2002, we launched the palladium  version of  BrachySeed.  In
January 2003, we discontinued our marketing and sale of the BrachySeed products.
In November  2002, we began  promoting  NMP22  BladderChek  to urologists in the
United States.

Our PSMA  technologies  are still in the early  stages of  development.  We have
significantly reduced operations at our AxCell subsidiary,  which is responsible
for the development certain of our technologies.  We may be unable to develop or
commercialize these products and technologies.

Our business is therefore subject to the risks inherent in the development of an
early stage biopharmaceutical business enterprise, such as the need:

o     to obtain  sufficient  capital to support the expenses of  developing  our
      technology and commercializing our products;

o     to ensure that our products are safe and effective;

o     to obtain regulatory approval for the use and sale of our products;

o     to manufacture  our products in sufficient  quantities and at a reasonable
      cost;

o     to develop a sufficient market for our products; and

o     to  attract  and  retain  qualified  management,   sales,   technical  and
      scientific staff.



                                     - 8 -

<PAGE>


The problems  frequently  encountered  using new technologies and operating in a
competitive  environment  also may affect our  business.  If we fail to properly
address these risks and attain our business  objectives,  our business  could be
significantly and adversely affected.

OUR PSMA  PRODUCT  DEVELOPMENT  PROGRAM IS NOVEL AND,  CONSEQUENTLY,  INHERENTLY
RISKY.

We are subject to the risks of failure  inherent in the  development  of product
candidates based on new technologies, including our PSMA technology. These risks
include the possibility that:

o     the technologies we use will not be effective;

o     our product candidates will be unsafe;

o     our  product  candidates  will fail to receive  the  necessary  regulatory
      approvals;

o     the product  candidates  will be hard to  manufacture  on a large scale or
      will be uneconomical to market; and

o     we will not successfully  overcome  technological  challenges presented by
      our potential new products.

Our other research and development  programs involve  similarly novel approaches
to human  therapeutics.  Consequently,  there is no precedent for the successful
commercialization of therapeutic products based on our PSMA technologies.  If we
fail to develop such products, our business could be significantly and adversely
affected.

ALL OF OUR POTENTIAL  ONCOLOGY  PRODUCTS WILL BE SUBJECT TO THE RISKS OF FAILURE
INHERENT IN THE  DEVELOPMENT OF DIAGNOSTIC OR THERAPEUTIC  PRODUCTS BASED ON NEW
TECHNOLOGIES.

Product  development  for cancer  treatment  involves a high degree of risk. The
product  candidates  we  develop,  pursue  or offer may not prove to be safe and
effective,  may not receive the necessary regulatory approvals, may be precluded
by  proprietary  rights of third parties or may not  ultimately  achieve  market
acceptance.   These  product  candidates  will  require  substantial  additional
investment,  laboratory  development,  clinical testing and regulatory approvals
prior  to  their  commercialization.  We may  experience  difficulties,  such as
inability to receive timely  regulatory  approvals,  that could delay or prevent
the successful development, introduction and marketing of new products.

Before we obtain  regulatory  approvals  for the  commercial  sale of any of our
products under development,  we must demonstrate through preclinical studies and
clinical  trials that the product is safe and efficacious for use in each target
indication.  The results from preclinical  studies and early clinical trials may
not be predictive of results that will be obtained in large-scale  testing.  Our
clinical trials may not demonstrate  safety and efficacy of a proposed  product,
and therefore,  may not result in marketable  products. A number of companies in
the  biotechnology  industry  have  suffered  significant  setbacks  in advanced
clinical trials, even after promising results in earlier trials. Clinical trials
or marketing of any potential  diagnostic or therapeutic  products may expose us
to liability claims for the use of these diagnostic or therapeutic  products. We
may not be able to maintain product liability  insurance or sufficient  coverage
may not be available at a reasonable cost. In addition, as we develop diagnostic
or therapeutic products internally, we will have to make significant investments
in  diagnostic  or  therapeutic  product  development,   marketing,   sales  and
regulatory compliance resources.  We will also have to establish or contract for
the  manufacture  of  products,  including  supplies  of drugs used in  clinical
trials, under the current Good Manufacturing  Practices, or cGMP, of the FDA. In
addition, the FDA may, among other things,



                                     - 9 -

<PAGE>


subsequently   disapprove  or  may  recall  our  product  candidates  that  were
previously  approved.  We also cannot  assure you that  product  issues will not
arise following successful clinical trials and FDA approval.

The rate of  completion  of clinical  trials also depends on the rate of patient
enrollment.  Patient enrollment  depends on many factors,  including the size of
the patient population, the nature of the protocol, the proximity of patients to
clinical  sites and the  eligibility  criteria for the study.  Delays in planned
patient enrollment may result in increased costs and delays,  which could have a
harmful effect on our ability to develop the products in our pipeline. If we are
unable to develop and  commercialize  products on a timely  basis or at all, our
business could be significantly and adversely affected.

COMPETITION IN OUR FIELD IS INTENSE AND LIKELY TO INCREASE.

We face, and will continue to face, intense  competition from one or more of the
following entities:

o     pharmaceutical companies;

o     biotechnology companies;

o     bioinformatics companies;

o     diagnostic companies;

o     academic and research institutions; and

o     government agencies.

All of our products and product candidate are subject to significant competition
from organizations that are pursuing technologies and products that are the same
as or  similar  to our  technology  and  products.  Many  of  the  organizations
competing  with us have greater  capital  resources,  research  and  development
staffs and facilities and marketing capabilities.

The markets for  therapeutic and diagnostic  products that address  prostate and
bladder  cancers are large.  Our most  significant  competitors  include various
pharmaceutical  and medical device companies,  radiopharmaceutical  distributors
and biotechnology companies.

Metastron   (Strontium-89),   which   competes  with   Quadramet   (Samarium-153
Lexidronam),  is manufactured and distributed by Amersham  Health.  Amersham has
announced plans to transfer  marketing  rights for Metastron to Oncura.  The FDA
recently approved a generic version of Sr-89 for bone pain palliation,  which is
marketed by Bio-Nucleonics Pharma as Strontium Chloride Sr-89 Injection, USP.

A single agent,  Positron Emission  Tomography (PET),  competes with ProstaScint
(Capromab pendetide). PET imaging agent, 18-F  fluorodeoxyglucose-PET  (FDG), is
produced  and  distributed  by various  radiopharmaceutical  suppliers  (such as
PETnet and Cardinal  Health Nuclear  Pharmacy  Services).  PET (FDG) may also be
used to image  lymph  node  metastasis  in  cancer  patients,  which  may  prove
competitive  to Combidex,  following FDA approval,  if received,  and subsequent
market introduction of Combidex.

Polymedco  manufactures  BTAstat,  a point of care urine-based test approved for
monitoring bladder cancer patients.  BTAstat,  marketed by Mentor, competes with
NMP22 BladderChek (which we have licensed from Matritech). NMP22 BladderChek is,
however,  the only point of care  urine-based  test approved for both monitoring
and diagnosis of bladder  cancer.  Matritech has retained rights to market



                                     - 10 -

<PAGE>


NMP22 BladderChek  directly to physicians other than urologists and oncologists,
such as primary care physicians.

Additionally,  we face competition in the development of PSMA-related technology
and products primarily from Millenium Pharmaceuticals, Inc. and Medarex, Inc.

Before we recover  development  expenses for our products and technologies,  the
products  or  technologies  may  become  obsolete  as a result of  technological
developments  by others or us. Our products  could also be made  obsolete by new
technologies,  which are less expensive or more effective. We may not be able to
make the enhancements to our technology  necessary to compete  successfully with
newly  emerging  technologies  and  failure  to do so  could  significantly  and
adversely affect our business.

WE RELY HEAVILY ON OUR COLLABORATIVE PARTNERS.

Our success depends in significant part upon the success and financial stability
of our collaborative partners. We have entered into the following agreements for
the sale,  marketing,  distribution  and  manufacture  of our products,  product
candidates and technologies:

o     license  from  The  Dow  Chemical   Company   relating  to  the  Quadramet
      technology;

o     agreement for  manufacture of Quadramet by Bristol Myers Squibb  (formerly
      The DuPont Pharmaceuticals Company);

o     joint venture with Progenics  Pharmaceuticals  for the development of PSMA
      for in vivo immunotherapy for prostate and other cancers;

o     licensing  agreement with  Molecular  Staging for technology to be used in
      developing  in vitro  diagnostic  tests using PSMA and  prostate  specific
      antigen, or PSA;

o     a Supply  Agreement  with  Laureate  Pharma  L.P.  for the  production  of
      ProstaScint;

o     an agreement with Matritech to market and distribute NMP22  BladderChek to
      urologists and oncologists in the United States;

o     marketing,  license and supply  agreements with Advanced  Magnetics,  Inc.
      related to Combidex and Code 7228;

o     a License  Agreement between our joint venture,  PSMA Development  Company
      LLC, and AlphaVax Human Vaccines, Inc.; and

o     a Collaboration Agreement between our joint venture and Abgenix, Inc.

Because our collaborative partners are responsible for certain manufacturing and
distribution  activities,  among others, these activities are outside our direct
control and we rely on our partners to perform their  obligations.  For example,
Matritech  retained the ability to market its NMP22  BladderChek to primary care
physicians  and others and has begun such marketing  efforts.  In the event that
our collaborative  partners are entitled to enter into third party  arrangements
that may  economically  disadvantage us, or breach their  obligations  under our
agreements,  our products may not be commercially  successful.  As a result, any
success may be delayed and new product  development  could be inhibited with the
result that our business could be significantly and adversely affected.



                                     - 11 -

<PAGE>


OUR  BUSINESS  COULD BE HARMED IF CERTAIN  AGREEMENTS  EXPIRE OR ARE  TERMINATED
EARLY.

If our collaborative  agreements expire or are terminated and we cannot renew or
replace them on  commercially  reasonable  terms,  our  business  and  financial
results may suffer.  For example,  in January 2003, we provided  Draximage  Inc.
with  notice of our intent to  terminate  our Product  Manufacturing  and Supply
Agreement  and License  Agreement  with  Draximage  relating  to the  BrachySeed
products  which  represented  20% of our product  related  revenues for the year
ended  December 31,  2002.  In April 2003,  we entered  into an  agreement  with
Draximage formally terminating each of these agreements. We no longer market and
sell the BrachySeed products.

We  currently  depend on the  following  agreements  for our  present and future
operating results:

      Dow Chemical:

In March 1993, we obtained an exclusive license from The Dow Chemical Company to
North American rights to use Quadramet as a therapeutic  radiopharmaceutical for
metabolic  bone disease or tumor  regression  for cancer caused by metastatic or
primary cancer in bone in humans, and for the treatment of disease characterized
by  osteoblastic  response in humans.  Our license was expanded to include Latin
America in 1995. Our license  agreement with Dow with respect to Quadramet shall
remain in effect, unless earlier terminated pursuant to the terms thereof, for a
term of twenty (20) years from March 31, 1993 or until the last to expire of the
related  patents.  We currently  anticipate such  termination date to be June 9,
2015.

      Bristol-Myers Squibb:

Upon  our   reacquisition   of  marketing   rights  to  Quadramet   from  Berlex
Laboratories,  Inc. in August 2003, we assumed all of Berlex's right, duties and
obligations under that certain  Manufacturing and Supply Agreement dated January
1, 1999 by and among Cytogen,  Berlex and Bristol-Myers  Squibb (formerly DuPont
Pharmaceuticals  Company) for the manufacture of Quadramet. The original term of
this  agreement  was to expire on December  31,  2003.  However,  the  agreement
automatically  renews for successive two-year periods,  unless terminated by BMS
or  Cytogen  on two  years'  written  notice.  The  term of this  agreement  has
therefore been extended through December 31, 2005.

      Matritech:

In October 2002, we entered into a Distribution  Agreement with Matritech,  Inc.
to  be  the  sole  distributor  for  Matritech's  NMP22  BladderChek  device  to
urologists and  oncologists  in the United States.  Our retention of exclusivity
rights depends upon us meeting certain minimum annual  purchases.  Our agreement
with Matritech  shall remain in effect until  December 15, 2007,  unless earlier
terminated in accordance with terms of such agreement.  The agreement shall also
be renewed for  successive  one (1) year  terms,  upon  mutual  written  consent
provided at least ninety (90) days prior to the end of the term of the agreement
(including any renewal thereof).

      Laureate:

In January 2003, we entered into a Contract  Manufacturing  and Supply Agreement
with  Laureate  Pharma  L.P.,   pursuant  to  which  Laureate  is  obligated  to
manufacture  ProstaScint  for us through  December 31,  2003.  We do not plan to
manufacture any ProstaScint in 2004.



                                     - 12 -

<PAGE>


      Memorial Sloan-Kettering Cancer Center:

In 1993, we began a development  program with  Memorial  Sloan-Kettering  Cancer
Center involving PSMA and our proprietary monoclonal antibody. In November 1996,
we exercised an option for, and obtained, an exclusive worldwide license to this
technology.  The term of the license  shall end on the date of expiration of the
last to expire of the related patents unless it earlier  terminates by operation
of law or by acts of the parties in accordance with the terms of the agreement.

      The University of North Carolina at Chapel Hill:

In March 1993, we entered into a License  Agreement with The University of North
Carolina  at  Chapel  Hill,  pursuant  to  which  UNC  granted  Cytogen  and our
affiliates an exclusive  world-wide license with respect to certain  technology,
patents  and  patent  applications  related to  certain  aspects  of  proteomics
technology,  including our phage display.  The agreement  commenced on March 10,
1993 and will expire,  unless earlier  terminated as provided therein,  upon the
expiration  of the last to expire of the licensed  patents that cover a licensed
product.

      Advanced Magnetics, Inc.:

In August 2000, we entered into a license and marketing  agreement with Advanced
Magnetics,  Inc. for Combidex,  an  investigational  magnetic  resonance imaging
(MRI)  contrast  agent that assists in the  differentiation  of metastatic  from
non-metastatic  lymph nodes. We hold exclusive United States marketing rights to
Combidex. Advanced Magnetics is continuing its discussions with the FDA relating
to outstanding issues regarding an approvable letter received from the FDA dated
June 2000, in an effort to bring  Combidex to market.  Our license and marketing
agreement with Advanced Magnetics will continue until August 25, 2010, and shall
thereafter  automatically renew for successive five year periods,  unless notice
of  non-renewal or  termination  is given by us or Advanced  Magnetics,  90 days
prior to the commencement of any renewal period.

If the licenses and/or agreements described above are terminated,  we may not be
able to find  suitable  alternatives  to them on a timely basis or on reasonable
terms, if at all. The loss of the right to use these  technologies  that we have
licensed or the loss of any services provided to us under these agreements would
significantly and adversely affect our business.

WE HAVE LIMITED SALES, MARKETING AND DISTRIBUTION CAPABILITIES FOR OUR PRODUCTS.

We have  established an internal  sales force that is responsible  for marketing
and selling ProstaScint, Quadramet and NMP22 BladderChek. However, such internal
sales force has limited sales,  marketing and distribution  capabilities for our
products,  compared  to those of many of our  competitors.  Effective  August 1,
2003, we reacquired marketing rights to Quadramet from Berlex Laboratories, Inc.
in North and Latin  America,  for an  upfront  payment of $8.0  million  and the
obligation  to pay  royalties  to Berlex on future  sales of  Quadramet.  If our
internal sales force is unable to successfully  market  Quadramet,  our business
and financial condition may be adversely affected. If we are unable to establish
and maintain  significant sales,  marketing and distribution  efforts within the
United States, either internally or through arrangements with third parties, our
business may be significantly  and adversely  affected.  In locations outside of
the United States, we have not established a selling presence.

THERE ARE RISKS ASSOCIATED WITH THE MANUFACTURE AND SUPPLY OF OUR PRODUCTS.

If we are to be  successful,  our  products  will  have  to be  manufactured  by
contract  manufacturers in compliance with regulatory  requirements and at costs
acceptable to us. If we are unable to  successfully



                                     - 13 -

<PAGE>


arrange for the  manufacture  of our  products  and product  candidates,  either
because  potential  manufacturers  are not cGMP compliant,  are not available or
charge excessive amounts, we will not be able to successfully  commercialize our
products and our business will be significantly and adversely affected.

ProstaScint was manufactured at a cGMP compliant manufacturing facility operated
by  Laureate  Pharma  L.P.  (formerly  Bard  BioPharma  L.P.).  We had access to
Laureate's  facility for  continued  manufacturing  of the product until January
2002.  We  entered  into a  Development  and  Manufacturing  Agreement  with DSM
Biologics  Company  B.V.  in July 2000,  which we  intended  would  replace  our
arrangement with Laureate with respect to ProstaScint. Our relationship with DSM
has  subsequently  terminated.  We  entered  into a new  Contract  Manufacturing
Agreement  with Laureate  Pharma L.P. in January 2003. Our failure to maintain a
long term supply agreement on commercially reasonable terms will have a material
adverse effect on our business, financial condition and results of operations.

Quadramet is  manufactured  by  Bristol-Myers  Squibb (BMS)  (formerly  DuPont),
pursuant  to  an  agreement   with  Cytogen.   Some   components  of  Quadramet,
particularly  Samarium153 and EDTMP,  are provided to BMS by outside  suppliers.
Due to radioactive  decay,  Samarium153  must be produced on a weekly basis. BMS
obtains its requirements for Samarium153 from one supplier.  Alternative sources
for  these  components  may  not be  readily  available.  If BMS  cannot  obtain
sufficient quantities of the components on commercially  reasonable terms, or in
a timely  manner,  it would be unable to  manufacture  Quadramet on a timely and
cost-effective  basis,  which  could  have  a  material  adverse  effect  on our
business, financial condition and results of operations.

Pursuant to the terms of our distribution  agreement with Matritech,  we rely on
Matritech as the sole supplier of NMP22 BladderChek.  Matritech uses independent
contractors to manufacture  the product.  If Matritech fails to, or is unable to
provide  the  product,  we could  experience  a material  adverse  effect on our
business, financial condition and results of operations.

The Company, our contract manufacturers and testing laboratories are required to
adhere to United  States Food & Drug  Administration  regulations  setting forth
requirements for cGMP, and similar regulations in other countries, which include
extensive testing,  control and documentation  requirements.  Ongoing compliance
with cGMP,  labeling and other applicable  regulatory  requirements is monitored
through  periodic  inspections  and  market  surveillance  by state and  federal
agencies,  including  the FDA, and by  comparable  agencies in other  countries.
Failure of our  contract  vendors or us to comply  with  applicable  regulations
could result in sanctions  being imposed on us,  including  fines,  injunctions,
civil  penalties,  failure of the  government  to grant  premarket  clearance or
premarket  approval of drugs,  delays,  suspension  or  withdrawal of approvals,
seizures  or  recalls  of   products,   operating   restrictions   and  criminal
prosecutions any of which could significantly and adversely affect our business.

FAILURE OF CONSUMERS TO OBTAIN ADEQUATE  REIMBURSEMENT  FROM THIRD-PARTY  PAYORS
COULD LIMIT MARKET ACCEPTANCE AND AFFECT PRICING OF OUR PRODUCTS.

Our business,  financial condition and results of operations will continue to be
affected by the efforts of governments and other  third-party  payors to contain
or reduce the costs of  healthcare.  There have been,  and we expect  that there
will  continue  to be, a number of  federal  and state  proposals  to  implement
government  control of pricing and  profitability  of therapeutic and diagnostic
imaging  agents such as our products.  In addition,  an emphasis on managed care
increases  possible  pressure  on  pricing  of these  products.  While we cannot
predict whether these  legislative or regulatory  proposals will be adopted,  or
the effects  these  proposals or managed care efforts may have on our  business,
the  announcement  of these  proposals  and the  adoption of these  proposals or
efforts  could affect our stock price or our  business.



                                     - 14 -

<PAGE>


Further,  to the extent these  proposals  or efforts  have an adverse  effect on
other  companies that are our  prospective  corporate  partners,  our ability to
establish necessary strategic alliances may be harmed.

Sales of our  products  depend in part on  reimbursement  to the  consumer  from
third-party payors,  including  Medicare,  Medicaid and private health insurance
plans.  Third-party  payors are increasingly  challenging the prices charged for
medical products and services. If third-party payors determine that our products
are  not  cost-effective,  they  may  discontinue  reimbursement  to  consumers.
Alternatively,  such reimbursement may not be sufficient to allow us to sell our
products on a competitive basis. Approval of our products for reimbursement by a
third-party  payor may  depend on a number of  factors,  including  the  payor's
determination  that our  products  are  clinically  useful  and  cost-effective,
medically  necessary and not experimental or  investigational.  Reimbursement is
determined by each payor  individually and in specific cases. The  reimbursement
process  can  be  time  consuming.  If we  cannot  secure  adequate  third-party
reimbursement  for  our  products,  our  business  could  be  significantly  and
adversely affected.

IF WE ARE UNABLE TO COMPLY WITH APPLICABLE GOVERNMENTAL REGULATION WE MAY NOT BE
ABLE TO CONTINUE OUR OPERATIONS.

Any products tested, manufactured or distributed by us or on our behalf pursuant
to FDA approvals are subject to pervasive and continuing  regulation by numerous
regulatory authorities, including primarily the FDA. We may be slow to adapt, or
we may never  adapt to changes  in  existing  requirements  or  adoption  of new
requirements  or policies.  Our failure to comply with  regulatory  requirements
could subject us to enforcement  action,  including product  seizures,  recalls,
withdrawal,   suspension,  or  revocation  of  approvals,   restrictions  on  or
injunctions  against  marketing our products based on our technology,  and civil
and criminal  penalties.  We may incur significant costs to comply with laws and
regulations in the future or compliance  with laws or regulations  may create an
unsustainable burden on our business.

Numerous federal, state and local governmental authorities, principally the FDA,
and similar  regulatory  agencies in other  countries,  regulate the preclinical
testing,  clinical trials,  manufacture and promotion of any compounds or agents
we or our collaborative partners develop, and the manufacturing and marketing of
any resulting drugs. The product  development and regulatory approval process is
lengthy, expensive, uncertain and subject to delays.

The regulatory risks we face also include the following:

o     any  compound  or  agent we or our  collaborative  partners  develop  must
      receive  regulatory agency approval before it may be marketed as a drug in
      a particular country;

o     the regulatory  process,  which includes  preclinical testing and clinical
      trials of each  compound  or agent in order to  establish  its  safety and
      efficacy, varies from country to country, can take many years and requires
      the expenditure of substantial resources;

o     in all  circumstances,  approval  of  the  use  of  previously  unapproved
      radioisotopes in certain of our products  requires  approval of either the
      Nuclear  Regulatory  Commission or equivalent state  regulatory  agencies,
      which may be a lengthy  process.  A radioisotope is an unstable form of an
      element which undergoes  radioactive  decay,  thereby  emitting  radiation
      which may be used,  for example,  to image or destroy  harmful  growths or
      tissue;

o     data obtained from preclinical and clinical  activities are susceptible to
      varying  interpretations  which could delay,  limit or prevent  regulatory
      agency approval; and



                                     - 15 -

<PAGE>


o     delays or rejections may be  encountered  based upon changes in regulatory
      agency policy during the period of product  development  and/or the period
      of review of any application for regulatory agency approval.  These delays
      could   adversely   affect  the  marketing  of  any  products  we  or  our
      collaborative   partners  develop,   impose  costly  procedures  upon  our
      activities,  diminish any competitive  advantages we or our  collaborative
      partners may attain and adversely affect our ability to receive royalties.

Regulatory  agency  approval  for a product or agent may not be received and may
entail  limitations on the indicated uses that could limit the potential  market
for any such  product.  For  example,  as  disclosed  in our press  releases and
periodic filings,  we have exclusive United States marketing rights to Combidex,
an ultrasmall superparamagnetic iron oxide contrast agent for magnetic resonance
imaging of lymph nodes,  that is pending clearance by the United States Food and
Drug  Administration.  In June 2000,  Advanced  Magnetics received an approvable
letter from the FDA with respect to Combidex.  An approvable letter is a written
communication  to an applicant from the FDA stating that the agency will approve
the application or abbreviated application if specific additional information or
material is submitted or specific  conditions are met. An approvable letter does
not constitute approval of any part of an application or abbreviated application
and does not permit marketing of the drug that is the subject of the application
or abbreviated  application.  We are awaiting  further  information from the FDA
regarding Combidex.

Furthermore, if and when such approval is obtained, the marketing,  manufacture,
labeling,  packaging,  reporting,  storage, advertising and promotion and record
keeping  related to our products  would remain  subject to extensive  regulatory
requirements.  Discovery  of  previously  unknown  problems  with  a  drug,  its
manufacture  or its  manufacturer  may  result  in  restrictions  on such  drug,
manufacture or manufacturer,  including  withdrawal of the drug from the market.
Failure  to  comply  with  regulatory   requirements   could  result  in  fines,
injunctions,   seizures,   recalls,   suspension  or  withdrawal  of  regulatory
approvals, operating restrictions and criminal prosecution.

The United States Food, Drug and Cosmetics Act requires (i) that our products be
manufactured in FDA registered  facilities subject to inspection,  and (ii) that
we  comply  with  cGMP,  which  imposes  certain  procedural  and  documentation
requirements   upon  us  and  our   manufacturing   partners   with  respect  to
manufacturing and quality assurance  activities.  If we or our contract partners
do not  comply  with  cGMP we may be  subject  to  sanctions,  including  fines,
injunctions,  civil penalties, recalls or seizures of products, total or partial
suspension of production,  product  recalls,  failure of the government to grant
premarket  clearance or premarket  approval for drugs,  withdrawal  of marketing
approvals and criminal prosecution.

WE COULD BE NEGATIVELY  IMPACTED BY FUTURE  INTERPRETATION  OR IMPLEMENTATION OF
FEDERAL  AND STATE  FRAUD AND ABUSE  LAWS,  INCLUDING  ANTI-KICKBACK  LAWS,  THE
FEDERAL STARK LAW AND OTHER FEDERAL AND STATE ANTI-REFERRAL LAWS.

We are subject to various federal and state laws pertaining to health care fraud
and  abuse,  including  anti-kickback  laws and  physician  self-referral  laws.
Violations  of these laws are  punishable  by criminal  and/or civil  sanctions,
including,  in some instances,  imprisonment and exclusion from participation in
federal  and state  health  care  programs,  including  Medicare,  Medicaid  and
Veterans  Administration  health  programs.  We have  not been  challenged  by a
governmental  authority  under any of these laws and believe that our operations
are in compliance with such laws. However, because of the far-reaching nature of
these laws,  we may be required to alter one or more of our  practices  to be in
compliance with these laws.  Health care fraud and abuse regulations are complex
and even minor,  inadvertent  irregularities can potentially give rise to claims
that the statute has been violated. Any violations of these laws could result in
a material  adverse effect on our business,  financial  condition and results of
operations.  If  there is a



                                     - 16 -

<PAGE>


change in law, regulation or administrative or judicial interpretations,  we may
have to change our business  practices or our existing business  practices could
be challenged  as unlawful,  which could have a material  adverse  effect on our
business, financial condition and results of operations.

We could become subject to false claims litigation under federal statutes, which
can lead to civil  money  penalties,  criminal  fines and  imprisonment,  and/or
exclusion from  participation in Medicare,  Medicaid and other federal and state
health care programs.  These false claims statutes include the False Claims Act,
which allows any person to bring suit alleging false or fraudulent  claims under
federal  programs or contracts  claims or other violations of the statute and to
share  in any  amounts  paid  by  the  entity  to the  government  in  fines  or
settlement.  Such suits, known as qui tam actions, have increased  significantly
in recent years and have increased the risk that a health care company,  such as
us, will have to defend a false claim action,  pay fines or be excluded from the
Medicare  program,  Medicaid  programs or other  federal  and state  health care
programs as a result of an investigation  arising out of such action.  If we are
unsuccessful  in  defending  against  any such  action,  such  action may have a
material  adverse  effect on our  business,  financial  condition and results of
operations.

WE DEPEND ON ATTRACTING AND RETAINING KEY PERSONNEL.

We are  highly  dependent  on  the  principal  members  of  our  management  and
scientific  staff.  The  loss of their  services  might  significantly  delay or
prevent the  achievement  of development  or strategic  objectives.  Our success
depends  on our  ability  to retain  key  employees  and to  attract  additional
qualified employees.  Competition for personnel is intense, and therefore we may
not be able to retain existing personnel or attract and retain additional highly
qualified employees in the future.

During 2002, we announced  numerous changes to members of our senior management.
H. Joseph Reiser,  Ph.D. who held the position of President and Chief  Executive
Officer of the Company from April 1998 until  December  2002,  resigned from his
position for personal reasons.  Michael D. Becker,  our former Vice President of
Business Development, was unanimously elected by our board of directors to serve
as Dr. Reiser's replacement as President and Chief Executive Officer. Mr. Becker
was also unanimously elected to serve on our Board of Directors.  Dr. Reiser has
remained a member of our Board of Directors.  In addition,  Lawrence R. Hoffman,
our Vice President and Chief Financial Officer since July 2000, left the Company
to pursue  other  opportunities  as of  December  31,  2002.  Ms. Thu Dang,  our
Director of Finance, was subsequently promoted to Vice President of Finance.

Additionally,  in the first  quarter of 2003:  (i) William  Goeckeler,  our Vice
President  of  Research  and   Development   was  promoted  to  Vice  President,
Operations;  (ii) Deborah  Kaminsky,  our Vice President of Sales and Marketing,
shifted her work focus, and serves as our Vice President,  Business Development;
(iii)  Rita  Auld,  our  Director  of  Human  Resources,  was  promoted  to Vice
President,  Human Resources and  Administration  and Corporate  Secretary;  (iv)
Corey Jacklin assumed the  responsibilities of Senior Director of Sales; and (v)
June Gobern was promoted to Senior Director of Marketing.

On September  4, 2003,  Christopher  P.  Schnittker  joined  Cytogen as our Vice
President and Chief Financial Officer.

On December 17, 2002, we entered into a letter  agreement with Michael D. Becker
in  connection  with Mr.  Becker's  promotion to President  and Chief  Executive
Officer of the Company.  Under the terms of such letter  agreement,  Mr.  Becker
receives an annual  base  salary of  $250,000.  Mr.  Becker is also  eligible to
participate  in  our  Cytogen  Corporation  Performance  Bonus  Plan,  as and if
approved  by our Board of  Directors,  with a target  bonus  rate of 30% of base
salary based upon  performance  objectives.  Mr.  Becker is also entitled to all
existing Company benefits, at the sole discretion of the Board of Directors.  In
addition,  Mr.  Becker was  granted  options to purchase  200,000  shares of our
common  stock  under our



                                     - 17 -

<PAGE>


1995 Stock Option Plan.  Pursuant to the terms of the letter  agreement,  in the
event we terminate Mr. Becker's  employment for reasons other than for cause, as
defined therein, Mr. Becker shall be entitled to receive twelve month's base pay
and  continuation  of  benefits  under  COBRA,  and a pro  rata  portion  of any
incentive benefits earned through the date of termination.

Each of our  executive  officers is currently  party to an  Executive  Change of
Control Severance Agreement with Cytogen.  Such agreements  provide,  generally,
for the  payment of twelve  months'  base  salary,  a  pro-rata  portion of such
officer's  bonus  compensation,  the  continuation  of all benefits,  reasonable
Company-paid  outplacement  assistance and certain other accrued rights,  in the
event such officer's employment with us is terminated in connection with certain
changes in control.

We do not carry key person life insurance policies and we do not typically enter
into long-term arrangements with our key personnel. If we are unable to hire and
retain  personnel in key  positions,  our business  could be  significantly  and
adversely affected unless qualified replacements can be found.

OUR  BUSINESS  EXPOSES  US TO  POTENTIAL  LIABILITY  CLAIMS  THAT MAY EXCEED OUR
FINANCIAL  RESOURCES,  INCLUDING  OUR  INSURANCE  COVERAGE,  AND MAY LEAD TO THE
CURTAILMENT OR TERMINATION OF OUR OPERATIONS.

Our  business is subject to product  liability  risks  inherent in the  testing,
manufacturing  and marketing of our products and product liability claims may be
asserted  against us, our  collaborators  or our  licensees.  While we currently
maintain  product  liability  insurance  in the  amount of $10.0  million,  such
coverage  may not be adequate  to protect us against  future  product  liability
claims. In addition,  product liability  insurance may not be available to us in
the future on commercially reasonable terms, if at all. Although we have not had
a history of claims  payments  that have  exceeded  our  insurance  coverage  or
available  financial  resources,  if  liability  claims  against  us exceed  our
financial resources or coverage amounts, we may have to curtail or terminate our
operations.  In addition,  while we currently  maintain  directors  and officers
liability  insurance in the amount of $20.0  million,  such  coverage may not be
available on  commercially  reasonable  terms or be adequate to cover any claims
that we may be  required  to satisfy in the future.  Our  insurance  coverage is
subject to industry standard and certain other limitations.

OUR BUSINESS INVOLVES ENVIRONMENTAL RISKS THAT MAY RESULT IN LIABILITY.

We are subject to a variety of local,  state,  federal  and  foreign  government
regulations  relating to storage,  discharge,  handling,  emission,  generation,
manufacture and disposal of toxic, infectious or other hazardous substances used
to manufacture  our products.  If we fail to comply with these  regulations,  we
could be liable  for  damages,  penalties,  or other  forms of  censure  and our
business  could be  significantly  and adversely  affected.  We currently do not
carry  insurance  for  contamination  or injury  resulting  from the use of such
materials.

Two of our marketed  products,  ProstaScint  and Quadramet  utilize  radioactive
materials.  ProstaScint is not manufactured or shipped as a radioactive material
because the radioactive  component is not added until the product has arrived at
its  final  destination  (a   radiopharmacy).   Laureate  Pharma,  the  contract
manufacturer of ProstaScint,  holds a radioactive materials license because such
license is required for certain release and stability tests of the product.

Quadramet,  however, is manufactured and shipped as radioactive,  and therefore,
the  manufacturing and distribution of this product must comply with regulations
promulgated  by the U.S.  Nuclear  Regulatory  Commission.  Bristol Myers Squibb
manufacturers and distributes  Quadramet,  and is,  therefore,  subject to these
regulations.



                                     - 18 -

<PAGE>


OUR INTELLECTUAL PROPERTY IS DIFFICULT TO PROTECT.

Our business and competitive positions are dependent upon our ability to protect
our  proprietary  technology.  Because  of the  substantial  length  of time and
expense  associated with  development of new products,  we, like the rest of the
biopharmaceutical  industry,  place  considerable  importance  on obtaining  and
maintaining  patent and trade secret protection for new  technologies,  products
and  processes.  We  have  filed  patent  applications  for our  technology  for
diagnostic  and  therapeutic  products and the methods for their  production and
use.

In  addition,  the  protection  afforded by a duly  issued  patent is limited in
duration.  With respect to our ProstaScint  product, we rely primarily on United
States patent numbers 5,763,202  (expiring June 9, 2015) and 5,162,504 (expiring
October 28, 2010).  Such patents were assigned to us by Julius S.  Horosziewicz.
With respect to Quadramet,  we rely  primarily on United  States patent  numbers
5,066,478  (expiring  November 19, 2008),  5,300,279  (expiring  April 5, 2011),
5,762,907  (expiring  June 19,  2015),  5,714,604  (expiring  February 3, 2015),
4,897,254  (expiring January 30, 2007) and 4,898,724  (expiring March 28, 2011),
which were licensed to us by The Dow Chemical Company.  In addition,  we rely on
United States patent number  5,495,042  (expiring  November 4, 2013),  which was
assigned to us by Benjamin A. Belinka, Jr.

The patent  positions of  pharmaceutical,  biopharmaceutical  and  biotechnology
companies,  including us, are generally  uncertain and involve complex legal and
factual questions.  Our patent applications may not protect our technologies and
products because, among other things:

o     there is no guarantee  that any of our pending  patent  applications  will
      result in issued patents;

o     we  may  develop   additional   proprietary   technologies  that  are  not
      patentable;

o     there is no guarantee that any patents issued to us, our  collaborators or
      our licensors will provide a basis for a commercially viable product;

o     there is no guarantee that any patents  issued to us or our  collaborators
      will provide us with any competitive advantage;

o     there is no guarantee that any patents  issued to us or our  collaborators
      will not be challenged, circumvented or invalidated by third parties; and

o     there is no  guarantee  that any  patents  previously  issued to others or
      issued in the future will not have an adverse  effect on our ability to do
      business.

In  addition,  patent  law in the  technology  fields  in  which we  operate  is
uncertain and still evolving.  The degree of protection that may be afforded any
patents we are issued or license  from others may not be  sufficient  to protect
our commercial interests.  Furthermore, others may independently develop similar
or  alternative  technologies,  duplicate our  technologies,  or, if patents are
issued to us, design around the patented technologies  developed by us. We could
incur  substantial costs in litigation if we are required to defend ourselves in
patent suits by third  parties or if we initiate  such suits.  In  addition,  if
challenged by others in litigation, the patents we have been issued, or which we
have been assigned or we have licensed from others may be found  invalid.  It is
also possible that our activities may infringe patents owned by others.  Defense
and  prosecution  of patent  matters can be expensive  and  time-consuming  and,
regardless  of  whether  the  outcome  is  favorable  to us,  can  result in the
diversion of substantial financial,  managerial and other resources.  An adverse
outcome could:



                                     - 19 -

<PAGE>


o     subject us to significant liability to third parties;

o     require us to cease any related  research and  development  activities and
      product sales; or

o     require us to obtain licenses from third parties.

Any licenses required under any such third-party  patents or proprietary  rights
may not be available on commercially  reasonable terms, if at all. Moreover, the
laws of certain  countries  may not protect our  proprietary  rights to the same
extent as the laws of the United States.  We cannot  predict  whether our or our
competitors'  pending patent  applications  will result in the issuance of valid
patents which may significantly and adversely affect our business.

OUR SECURITY MEASURES MAY NOT PROTECT OUR UNPATENTED PROPRIETARY TECHNOLOGY.

We also rely upon  trade  secret  protection  for some of our  confidential  and
proprietary  information that is not subject matter for which patent  protection
is available. To help protect our rights, we require all employees, consultants,
advisors and collaborators to enter into confidentiality agreements that require
disclosure,  and in most cases, assignment to us, of their ideas,  developments,
discoveries  and  inventions,  and that prohibit the disclosure of  confidential
information  to anyone  outside  Cytogen or our  subsidiaries.  Although  we are
unaware of any  unauthorized  use or  disclosure of our  unpatented  proprietary
technology to date, these agreements may not provide adequate protection for our
trade  secrets,  know-how  or other  proprietary  information  or  prevent  such
unauthorized use or disclosure.

WE ARE CURRENTLY SUBJECT TO PATENT LITIGATION.

On March 17,  2000,  we were  served with a  complaint  filed  against us in the
United  States  District  Court  for the  District  of New  Jersey  by M.  David
Goldenberg  ("Goldenberg") and Immunomedics,  Inc. (collectively  "Plaintiffs").
The  litigation   claims  that  our  ProstaScint   product  infringes  a  patent
purportedly  owned by Goldenberg and licensed to  Immunomedics.  We believe that
ProstaScint  does not infringe  this patent,  and that the patent is invalid and
unenforceable.  The  patent  sought to be  enforced  in the  litigation  has now
expired;  as a result,  the claim,  even if  successful,  would not result in an
injunction  barring the continued sale of ProstaScint or affect any other of our
products or technology.  In addition,  we have certain rights to indemnification
against litigation and litigation  expenses from the inventor of technology used
in  ProstaScint,  which  may be  offset  against  royalty  payments  on sales of
ProstaScint.  However, given the uncertainty associated with litigation,  we may
incur material  expenditures.  On December 17, 2001,  Cytogen filed a motion for
summary   judgment  of   non-infringement   of  the   asserted   claims  of  the
patent-in-suit.   The  Plaintiffs  opposed  that  motion  and  filed  their  own
cross-motion for summary  judgment of  infringement.  On July 3, 2002, the Court
denied both parties' summary judgment motions, with leave to renew those motions
after presenting  expert testimony and legal argument based upon that testimony.
The parties  subsequently  presented expert  testimony and submitted  additional
briefing. On April 29, 2003, our motion for summary judgment of non-infringement
of all asserted claims was granted,  plaintiffs'  motion for summary judgment of
infringement  was  denied  and the case was  ordered  closed.  On May 12,  2003,
Plaintiffs filed a Notice of Appeal regarding this decision to the U.S. Court of
Appeals for the Federal Circuit,  and subsequently  filed their opening brief in
the Court of Appeals for the Federal  Circuit on July 28, 2003. On September 22,
2003,  Cytogen filed its responsive  brief. The Court has not yet set a date for
the argument on this appeal.



                                     - 20 -

<PAGE>

OUR STOCK PRICE HAS BEEN AND MAY CONTINUE TO BE VOLATILE, AND YOUR INVESTMENT IN
OUR STOCK COULD DECLINE IN VALUE OR FLUCTUATE SIGNIFICANTLY.

The market prices for securities of biotechnology and  pharmaceutical  companies
have  historically  been highly  volatile,  and the market has from time to time
experienced  significant price and volume fluctuations that are unrelated to the
operating  performance of particular  companies.  The market price of our common
stock has fluctuated over a wide range and may continue to fluctuate for various
reasons, including, but not limited to, announcements concerning our competitors
or us regarding:

o     results of clinical trials;

o     technological innovations or new commercial products;

o     changes  in  governmental  regulation  or the  status  of  our  regulatory
      approvals or applications;

o     changes in earnings;

o     changes in health care policies and practices;

o     developments or disputes concerning proprietary rights;

o     litigation or public  concern as to safety of the our potential  products;
      and

o     changes in general market conditions.

These  fluctuations may be exaggerated if the trading volume of our common stock
is low. These  fluctuations  may or may not be based upon any of our business or
operating results. Our common stock may experience similar or even more dramatic
price and volume fluctuations which may continue indefinitely.

The following table sets forth the high and low sale prices for our common stock
for each of the quarters in the period beginning July 1, 2000 through  September
30, 2003 as  reported on the Nasdaq  National  Market,  and as adjusted  for our
one-for-ten reverse stock split effected October 25, 2002:

    Quarter Ended               High                    Low
    -------------               ----                    ---

 September 30, 2000            $113.75                  $55.00
 December 31, 2000              $71.88                  $20.00
 March 31, 2001                 $65.63                  $23.13
 June 30, 2001                  $61.00                  $21.88
 September 30, 2001             $53.90                  $19.00
 December 31, 2001              $45.50                  $20.50
 March 31, 2002                 $34.70                  $21.10
 June 30, 2002                  $22.40                   $9.10
 September 30, 2002             $11.50                  $3.20
 December 31, 2002              $8.44                   $2.68
 March 31, 2003                 $3.90                   $2.51
 June 30, 2003                  $8.60                   $2.80
 September 30, 2003             $14.78                  $8.40



                                     - 21 -

<PAGE>


WE HAVE ADOPTED VARIOUS  ANTI-TAKEOVER  PROVISIONS WHICH MAY AFFECT THE MARKET
PRICE  OF  OUR  COMMON  STOCK  AND  PREVENT  OR  FRUSTRATE   ATTEMPTS  BY  OUR
STOCKHOLDERS TO REPLACE OR REMOVE OUR MANAGEMENT TEAM.

Our Board of Directors has the authority,  without further action by the holders
of common stock, to issue from time to time, up to 5,400,000 shares of preferred
stock in one or more classes or series, and to fix the rights and preferences of
the  preferred  stock.  Pursuant  to these  provisions,  we have  implemented  a
stockholder  rights plan by which one preferred stock purchase right is attached
to each share of common stock, as a means to deter coercive takeover tactics and
to prevent an acquirer  from  gaining  control of us without  some  mechanism to
secure a fair price for all of our stockholders if an acquisition was completed.
These  rights  will be  exercisable  if a person  or group  acquires  beneficial
ownership  of 20% or more of our  common  stock and can be made  exercisable  by
action of our board of directors  if a person or group  commences a tender offer
which would  result in such person or group  beneficially  owning 20% or more of
our common stock.  Each right will entitle the holder to buy one  one-thousandth
of a share of a new series of our junior participating  preferred stock for $20.
If any person or group becomes the beneficial owner of 20% or more of our common
stock (with certain  limited  exceptions),  then each right not owned by the 20%
stockholder  will  entitle its holder to  purchase,  at the right's then current
exercise price, common shares having a market value of twice the exercise price.
In addition,  if after any person has become a 20% stockholder,  we are involved
in a merger or other business combination  transaction with another person, each
right will entitle its holder (other than the 20%  stockholder) to purchase,  at
the right's then current exercise price,  common shares of the acquiring company
having a value of twice the right's then current exercise price.

We are subject to provisions of Delaware corporate law which, subject to certain
exceptions,  will prohibit us from engaging in any "business combination" with a
person who,  together with  affiliates and  associates,  owns 15% or more of our
common stock for a period of three years following the date that the person came
to own 15% or more of our  common  stock  unless  the  business  combination  is
approved in a prescribed manner.

These   provisions  of  the   stockholder   rights  plan,  our   certificate  of
incorporation, and of Delaware law may have the effect of delaying, deterring or
preventing a change in control of Cytogen,  may  discourage  bids for our common
stock at a premium over market price and may adversely  affect the market price,
and the  voting  and other  rights  of the  holders,  of our  common  stock.  In
addition,  these  provisions  make it more  difficult  to  replace or remove our
current  management team in the event our stockholders  believe this would be in
the best interest of the Company and our stockholders.

THE LIQUIDITY OF OUR COMMON STOCK COULD BE ADVERSELY AFFECTED IF WE ARE DELISTED
FROM THE NASDAQ NATIONAL MARKET.

On August 14, 2002,  we announced  that we had  received  notification  from the
Nasdaq  Stock  Market,  Inc.  that our common stock had closed below the minimum
$1.00 per share  requirement  for the  previous 30  consecutive  trading days as
required under Marketplace Rule 4450(a)(5).  In accordance with Marketplace Rule
4450 (e)(2), we were provided with 90 calendar days, or until November 12, 2002,
to regain compliance by having the bid price for our common stock close at $1.00
or greater for a minimum period of 10 consecutive trading days.

On September  26, 2002,  we  announced  that our Board of Directors  unanimously
approved,  and recommended to our  stockholders,  a proposal that would give the
Board of  Directors  authority  to effect a reverse  stock  split of our  common
stock, at a ratio of up to one-for-ten at any time prior to December 31, 2002. A
special  meeting of our  stockholders  was held on October  25, 2002 to consider
such recommendation. Pursuant to the authority granted to our Board of Directors
at the special  meeting,  on



                                     - 22 -

<PAGE>


October 25, 2002, we implemented a one-for-ten  reverse split of our outstanding
and authorized shares of common stock.

We subsequently achieved compliance with Nasdaq Marketplace Rule 4450(a)(5), and
received a letter from Nasdaq  notifying us of such  compliance  on November 11,
2002.

If we do not continue to maintain  compliance with this Marketplace Rule, or any
other Listing  Standards which may apply to us, we may once again face delisting
from the Nasdaq National Market in the future.

In the event that we are unable  maintain  compliance  with all relevant  Nasdaq
Listing  Standards,  our  securities may be subject to delisting from the Nasdaq
National Market. If such delisting occurs, the market price and market liquidity
of our common stock may be adversely affected.

Alternatively,  if faced with such  delisting,  we may submit an  application to
transfer  the listing of our common  stock to the Nasdaq  SmallCap  Market.  The
Nasdaq SmallCap Market also has a $1.00 minimum bid price requirement.

If our common stock is delisted by Nasdaq, our common stock would be eligible to
trade on the OTC Bulletin Board maintained by Nasdaq,  another  over-the-counter
quotation  system,  or on the pink  sheets  where an  investor  may find it more
difficult to dispose of or obtain accurate  quotations as to the market value of
our common stock. In addition,  we would be subject to a rule promulgated by the
Securities and Exchange  Commission  that, if we fail to meet criteria set forth
in such rule,  imposes various practice  requirements on broker-dealers who sell
securities governed by the rule to persons other than established  customers and
accredited  investors.  Consequently,  such rule may deter  broker-dealers  from
recommending or selling our common stock, which may further affect the liquidity
of our common stock.

Delisting  from Nasdaq will make  trading our common  stock more  difficult  for
investors,  potentially leading to further declines in our share price. It would
also make it more difficult for us to raise additional  capital.  Further, if we
are delisted we would also incur  additional  costs under state blue sky laws in
connection with any sales of our securities.  These  requirements could severely
limit  the  market  liquidity  of  our  common  stock  and  the  ability  of our
shareholders to sell our common stock in the secondary market.

A LARGE NUMBER OF OUR SHARES ARE  ELIGIBLE  FOR FUTURE SALE WHICH MAY  ADVERSELY
IMPACT THE MARKET PRICE OF OUR COMMON STOCK.

A large number of shares of our common stock are already  outstanding,  issuable
upon exercise of options and warrants,  or the achievement of certain milestones
under previously  completed  acquisitions and may be eligible for resale,  which
may adversely  affect the market price of our common  stock.  As of September 8,
2003 we had  10,992,382  shares of common  stock  outstanding,  which  number of
shares:  (i) includes an aggregate of 241 shares of common stock to be issued to
prior holders of securities of CytoRad Incorporated and Cellcor,  Inc., which we
acquired in 1995, upon each such holders respective exchange of such securities;
(ii)  excludes  50,000  shares  of  common  stock  previously  issued  by us and
currently held in escrow pending release,  upon certain conditions,  to Advanced
Magnetics, who currently maintains voting control of such securities;  and (iii)
excludes 27,527 shares  previously  issued by us and currently held for issuance
by the  custodian  of our  Employee  Stock  Purchase  Plan  to the  participants
thereunder,  in the event they elect to  purchase  such  shares.  An  additional
414,018  shares of common  stock are issuable  upon the exercise of  outstanding
stock  options and an additional  1,944,485  shares of common stock are issuable
upon the exercise of outstanding warrants,  including the warrants issued to the
selling  stockholders  in this  prospectus.  Substantially  all of  such  shares
subject to  outstanding  options and warrants  will,  when issued upon  exercise
thereof,  be available  for immediate  resale in the public  market



                                     - 23 -

<PAGE>


pursuant  to  either a  currently  effective  registration  statement  under the
Securities  Act of  1933,  as  amended,  or  pursuant  to Rule  144 or Rule  701
promulgated  thereunder.  In addition,  there are 148,397  additional  shares of
common stock reserved for future issuance under our current stock options plans,
3,630  additional  shares of common stock reserved for issuance under our 401(k)
Plan and  22,751  additional  shares of common  stock  reserved  for the  future
issuance  under our  employee  bonus plan.  All such  reserved  shares have been
registered  with the  Securities and Exchange  Commission  pursuant to currently
effective  registration  statements.  In addition,  there are 85,480  additional
shares of common  stock,  subject to certain  adjustments,  reserved  for future
issuance in  connection  with the  issuance of a  convertible  promissory  note,
having a seven (7) year maturity, to ELAN Corporation, plc in August 1998.

In connection  with our  acquisition of Prostagen,  Inc. in June 1999, we issued
205,000  unregistered  shares of our common  stock to the then  stockholders  of
Prostagen, which shares may be sold from time to time pursuant to Rule 144 under
the Securities Act. Such stockholders  also have certain piggyback  registration
rights with  respect to these  shares of common  stock.  An  additional  127,699
shares  have  been  issued  in  2002  and  were  subsequently  registered  on  a
registration  statement on Form S-3. An additional $2.0 million worth of Cytogen
common stock,  which we are obligated to register  under the  Securities  Act of
1933, as amended,  may be issued if certain  milestones are achieved in the PSMA
development programs.

On October 25, 2001,  we filed with the  Securities  and  Exchange  Commission a
shelf registration statement on Form S-3 covering 1,000,000 shares of our common
stock. 297,066 and 416,670 of such registered shares were issued to the State of
Wisconsin  Investment Board in private offering  transactions in each of January
2002 and June 2002, respectively.

On July 3, 2003,  we filed  with the SEC a  Registration  Statement  on Form S-3
covering 1,368,422 shares of our common stock, 315,790 of which shares of common
stock are  underlying  warrants.  Such shares of common stock and warrants  were
issued in a private offering  transaction.  Such  Registration  Statement became
effective on September 23, 2003.

On October 1, 2003, we filed with the SEC a  Registration  Statement on Form S-3
covering  2,694,664  shares of our common  stock,  1,522,332  of which shares of
common stock are underlying  warrants.  2,344,664 of such shares of common stock
and warrants were issued in a private offering  transaction,  100,000 additional
warrants  were issued to a  consultant  in  connection  with the  financing  and
250,000  additional  warrants were issued in consideration for certain entities'
waiver  of  certain  rights  with  respect  to the  July  2003  financing.  Such
Registration Statement became effective on October 6, 2003.

Availability  of a significant  number of additional  shares of our common stock
for future sale and issuance could depress the price of our common stock.

BECAUSE WE DO NOT INTEND TO PAY,  AND HAVE NOT PAID,  ANY CASH  DIVIDENDS ON OUR
SHARES OF COMMON STOCK, OUR STOCKHOLDERS WILL NOT BE ABLE TO RECEIVE A RETURN ON
THEIR SHARES UNLESS THE VALUE OF OUR SHARES APPRECIATES AND THEY SELL THEM.

We have never paid or declared  any cash  dividends on our common stock or other
securities and intend to retain any future  earnings to finance the  development
and expansion of our business. We do not anticipate paying any cash dividends on
our common stock in the foreseeable future. Therefore, our stockholders will not
be able to  receive  a return on their  shares  unless  the value of our  shares
appreciates and they sell them.



                                     - 24 -

<PAGE>


                SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

      This prospectus includes or incorporates forward-looking statements within
the meaning of Section 27A of the  Securities Act of 1933 and Section 21E of the
Securities  Exchange  Act of  1934,  as  amended.  All  statements,  other  than
statements of historical  facts,  included or  incorporated  in this  prospectus
regarding our strategy, future operations,  financial position, future revenues,
projected   costs,   prospects,   plans  and   objectives  of   management   are
forward-looking  statements.  The words "anticipates,"  "believes," "estimates,"
"expects,"  "intends," "may," "plans,"  "projects,"  "will," "would" and similar
expressions are intended to identify  forward-looking  statements,  although not
all  forward-looking  statements  contain  these  identifying  words.  We cannot
guarantee  that we actually will achieve the plans,  intentions or  expectations
disclosed  in our  forward-looking  statements  and you should  not place  undue
reliance  on our  forward-looking  statements.  Actual  results or events  could
differ materially from the plans,  intentions and expectations  disclosed in the
forward-looking  statements we make. We have included  important  factors in the
cautionary statements included or incorporated in this prospectus,  particularly
under the heading "Risk Factors",  that we believe could cause actual results or
events to differ  materially from the  forward-looking  statements that we make.
Our forward-looking statements do not reflect the potential impact of any future
acquisitions,  mergers, dispositions, joint ventures or investments we may make.
We do not assume any obligation to update any  forward-looking  statements.  You
should not unduly rely on forward-looking  statements  contained or incorporated
by  reference  in  this  prospectus.  Actual  results  or  outcomes  may  differ
materially  from those  predicted in our  forward-looking  statements due to the
risks and uncertainties inherent in our business.

      You should read and interpret any forward-looking statements together with
the following documents:

o     our most recent Annual Report on Form 10-K, as amended;

o     our most recent quarterly report of Form 10-Q;

o     the risk factors  contained  in this  prospectus  under the caption  "Risk
      Factors"; and

o     our other filings with the Securities and Exchange Commission.

      Any  forward-looking  statement  speaks  only as of the date on which that
statement is made. We will not update any  forward-looking  statement to reflect
events or  circumstances  that occur after the date on which such  statement  is
made.

                                 USE OF PROCEEDS

      Cytogen will not receive any proceeds from the sale of the Shares  covered
by this Prospectus. While Cytogen will receive sums upon any exercise of options
by  the  Selling   Shareholder,   Cytogen  currently  has  no  plans  for  their
application,  other than for general corporate  purposes.  Cytogen cannot assure
you that any of such options will be exercised.



                                     - 25 -

<PAGE>


                             THE SELLING SHAREHOLDER

      The  individual  listed  below  (the  "Selling  Shareholder")  has or will
acquire  the  Shares  being  registered  pursuant  to the  exercise  of  options
previously  granted to him by Cytogen.  The Shares may not be sold or  otherwise
transferred by the Selling  Shareholder  unless and until the applicable options
are exercised in accordance with their terms.

      The following table sets forth:  (i) the name of the Selling  Shareholder;
(ii) his position(s), office or other material relationship with Cytogen and its
predecessors  or  affiliates,  over the last  three  years;  (iii) the number of
shares of Common Stock owned (or subject to options or  convertible  securities)
by such Selling  Shareholder as of the date of this Prospectus and prior to this
offering; (iv) the number of shares of Common Stock which may be offered and are
being registered for the account of such Selling  Shareholder by this Prospectus
(all of which have been or may be acquired by the Selling  Shareholder  pursuant
to the exercise of options subject to the appropriate  vesting of such options);
and (v) the amount of Common  Stock to be owned by such Selling  Shareholder  if
such Selling  Shareholder  was to sell all of his shares of Common Stock covered
by this Prospectus.

      Cytogen cannot assure you that the Selling Shareholder will offer for sale
or sell any or all of the Shares offered by him pursuant to this Prospectus.

                              Number of Shares               Number of Shares /
                              / Percentage of                   Percentage of
                                Common Stock     Number of   Common Stock Owned
                             Prior to Offering   Shares of   After the Offering
                  Position       (both held        Common        (both held
                    with        directly and    Stock to be      directly or
      Name         Cytogen    indirectly) (1)     Offered      indirectly) (2)
--------------    --------   -----------------  -----------  -------------------

Kevin G. Lokay    Director     4,333 / * (3)       1,000          3,333 / *

-----

*     Less than one-percent.

(1)   Applicable percentage of ownership is based on 11,069,668 shares of Common
      Stock   outstanding  as  of  October  20,  2003,  plus  any  Common  Stock
      equivalents or convertible  securities held and shares  beneficially owned
      by such holder as set forth herein.

(2)   Assumes  that all  Shares  to be  offered,  as set forth  above,  are sold
      pursuant to this  offering  and that no other  shares of Common  Stock are
      acquired  or  disposed  of  by  the  Selling   Shareholder  prior  to  the
      termination of this  offering.  Because the Selling  Shareholder  may sell
      all,  some or none of his Shares or may acquire or dispose of other shares
      of Common Stock, no reliable  estimate can be made of the aggregate number
      of Shares  that will be sold  pursuant  to this  offering or the number or
      percentage  of shares of Common Stock that such Selling  Shareholder  will
      own upon completion of this offering.

(3)   Includes  3,333 vested and unvested  options to purchase  shares of Common
      Stock prior to this Offering.



                                     - 26 -

<PAGE>


                              PLAN OF DISTRIBUTION

      The Selling  Shareholder  has not advised Cytogen of any specific plan for
the sale or distribution of the Shares.  If and when they occur,  such sales may
be made in any of the following manners:

      o     On the Nasdaq  National  Market (or  through the  facilities  of any
            national securities exchange or U.S.  inter-dealer  quotation system
            of a registered national securities association, on which the shares
            are then listed, admitted to unlisted trading privileges or included
            for quotation);

      o     In public or privately negotiated transactions;

      o     In transactions involving principals or brokers;

      o     In a combination of such methods of sale; or

      o     Any other lawful methods.

      Although  sales of the Shares  are,  in  general,  expected  to be made at
market  prices  prevailing  at the time of sale,  the Shares may also be sold at
prices related to such prevailing market prices or at negotiated  prices,  which
may differ considerably.

      When  offering  the  Shares  covered  by  this  Prospectus,  such  Selling
Shareholder  and  any  broker-dealers  who  sell  the  Shares  for  the  Selling
Shareholder may be "underwriters"  within the meaning of the Securities Act, and
any profits  realized by such Selling  Shareholders and the compensation of such
broker-dealers may be underwriting discounts and commissions.

      Sales through  brokers may be made by any method of trading  authorized by
any stock exchange or market on which the Shares may be listed,  including block
trading in negotiated transactions. Without limiting the foregoing, such brokers
may act as  dealers  by  purchasing  any or all of the  Shares  covered  by this
Prospectus, either as agents for others or as principals for their own accounts,
and reselling such Shares pursuant to this Prospectus.  The Selling  Shareholder
may effect such  transactions  directly,  or  indirectly  through  underwriters,
broker-dealers  or agents acting on their behalf. In connection with such sales,
such  broker-dealers  or  agents  may  receive   compensation  in  the  form  of
commissions,  concessions, allowances or discounts, any or all of which might be
in excess of customary amounts.

      Such  Selling  Shareholder  is acting  independently  of Cytogen in making
decisions  with  respect to the timing,  manner and size of each sale of Shares.
Cytogen has not been advised of any definitive  selling  arrangement at the date
of this Prospectus  between such Selling  Shareholder and any  broker-dealer  or
agent.

      To the  extent  required,  the  names  of any  agents,  broker-dealers  or
underwriters and applicable commissions,  concessions,  allowances or discounts,
and any other required  information  with respect to any particular offer of the
Shares by the Selling Shareholder, will be set forth in a Prospectus Supplement.

      The  expenses  of  preparing  and filing this  Prospectus  and the related
Registration  Statement with the Securities and Exchange Commission will be paid
entirely by Cytogen.  Shares of Common Stock covered by this Prospectus also may
qualify to be sold pursuant to Rule 144 under the  Securities  Act,  rather than
pursuant to this Prospectus. The Selling Shareholder has been advised that he is
subject to the applicable  provisions of the Securities Exchange Act of 1934, as
amended, including without limitation, Rule 10b-5 thereunder.



                                     - 27 -

<PAGE>


      Neither  Cytogen nor the Selling  Shareholder  can estimate at the present
time the amount of  commissions  or discounts,  if any, that will be paid by the
Selling Shareholder on account of his sales of the Shares from time to time.

                                  LEGAL MATTERS

      The validity of the shares of Common Stock  offered  hereby will be passed
upon for Cytogen by Hale and Dorr LLP,  650 College  Road East,  Princeton,  New
Jersey 08540.

                                     EXPERTS

      The  consolidated   financial   statements  of  Cytogen   Corporation  and
subsidiaries  as of December  31,  2002 and for the year then  ended,  have been
incorporated by reference herein and in the  registration  statement in reliance
upon   the    reports    of   KPMG    LLP,    independent    accountants,    and
PricewaterhouseCoopers  LLP,  independent  auditors,  incorporated  by reference
herein,  and upon the  authority  of said  firms as experts  in  accounting  and
auditing. The audit report covering the December 31, 2002 consolidated financial
statements  refers to KPMG LLP's audit of the  adjustments  that were applied to
restate  the 2001 and 2000  consolidated  financial  statements,  as more  fully
described in Note 1 to the consolidated financial statements.  However, KPMG LLP
was not engaged to and did not audit,  review,  or apply any  procedures  to the
2001 and 2000 consolidated  financial statements other than with respect to such
adjustments.

      The consolidated  balance sheet of Cytogen  Corporation as of December 31,
2001 and the  consolidated  statements of operations,  stockholders'  equity and
cash flows for each of the years in the two-year period ended December 31, 2001,
have been incorporated by reference in this prospectus,  and in the registration
statement of which this  prospectus  is a part,  from the Annual  Report on Form
10-K of  Cytogen  Corporation.  The  financial  statements  for the years  ended
December 31, 2001 and  December  31, 2000 have been  audited by Arthur  Andersen
LLP,  independent public accountants,  as indicated in their report with respect
thereto,  and are incorporated by reference herein. The Company has not received
an updated or  reissued  copy of such  report  dated  February  5, 2002,  and is
relying solely upon the manually-signed report of Arthur Andersen LLP previously
provided to the Company in connection  with the Company's  Annual Report on Form
10-K for the year ended December 31, 2001. Arthur Andersen LLP has not consented
to the inclusion of their report in this prospectus,  and we have dispensed with
the requirement to file their consent in reliance on Rule 437a promulgated under
the  Securities  Act of  1933,  as  amended.  Because  Arthur  Andersen  has not
consented to the inclusion of their report in this  prospectus,  you will not be
able to recover  against Arthur  Andersen under Section 11 of the Securities Act
of 1933, as amended,  for any untrue  statements of a material fact contained in
the financial  statements audited by Arthur Andersen or any omissions to state a
material fact required to be stated therein.

                       WHERE YOU CAN FIND MORE INFORMATION

      We file reports,  proxy  statements and other  documents with the SEC. You
may read and copy any  document we file at the SEC's  public  reference  room at
Judiciary Plaza Building,  450 Fifth Street, N.W., Room 1024,  Washington,  D.C.
20549.  You  should  call  1-800-SEC-0330  for more  information  on the  public
reference  room. Our SEC filings are also available to you on the SEC's Internet
site at http://www.sec.gov.

      This prospectus is part of a registration statement that we filed with the
SEC. The registration  statement  contains more information than this prospectus
regarding us and our common stock, including certain exhibits and schedules. You
can  obtain a copy of the  registration  statement  from the SEC at the  address
listed above or from the SEC's Internet site.



                                     - 28 -

<PAGE>


                      INFORMATION INCORPORATED BY REFERENCE

      The SEC requires us to "incorporate" into this prospectus information that
we file  with  the SEC in  other  documents.  This  means  that we can  disclose
important  information to you by referring to other  documents that contain that
information.  The information incorporated by reference is considered to be part
of this  prospectus.  Information  contained in this  prospectus and information
that we file with the SEC in the future and  incorporate  by  reference  in this
prospectus automatically updates and supersedes previously filed information. We
incorporate  by reference the documents  listed below and any future  filings we
make with the SEC under  Sections  13(a),  13(c),  14 or 15(d) of the Securities
Exchange  Act of  1934,  prior  to the sale of all the  shares  covered  by this
prospectus.

      1.    Our Annual Report on Form 10-K for the year ended December 31, 2002,
            as filed with the  Securities  and Exchange  Commission on March 31,
            2003 (File No. 000-14879);

      2.    Amendment  No. 1 to our  Annual  Report on Form  10-K/A for the year
            ended  December 31, 2002, as filed with the  Securities and Exchange
            Commission on March 31, 2003 (File No. 000-14879);

      3.    Amendment  No. 2 to our  Annual  Report on Form  10-K/A for the year
            ended  December 31, 2002, as filed with the  Securities and Exchange
            Commission on September 19, 2003 (File No. 000-14879);

      4.    Our Current  Report on Form 8-K,  dated  January 17, 2003,  as filed
            with the  Securities  and  Exchange  Commission  on January 17, 2003
            (File No. 000-14879);

      5.    Our Current  Report on Form 8-K,  dated  January 24, 2003,  as filed
            with the  Securities  and  Exchange  Commission  on January 27, 2003
            (File No. 000-14879);

      6.    Our Current  Report on Form 8-K,  dated April 8, 2003, as filed with
            the  Securities  and Exchange  Commission on April 9, 2003 (File No.
            000-14879);

      7.    Our Current  Report on Form 8-K,  dated May 14, 2003,  as filed with
            the  Securities  and Exchange  Commission  on May 14, 2003 (File No.
            000-14879);

      8.    Our  Quarterly  Report on Form 10-Q for the period  ended  March 31,
            2003, as filed with the  Securities  and Exchange  Commission on May
            14, 2003 (File No. 000-14879);

      9.    Our Current  Report on Form 8-K,  dated June 6, 2003,  as filed with
            the  Securities  and Exchange  Commission  on June 9, 2003 (File No.
            000-14879);

      10.   Our Current  Report on Form 8-K,  dated June 18, 2003, as filed with
            the  Securities  and Exchange  Commission  on July 3, 2003 (File No.
            000-14879);

      11.   Our Current  Report on Form 8-K,  dated July 10, 2003, as filed with
            the  Securities  and Exchange  Commission on July 11, 2003 (File No.
            000-14879);

      12.   Our Current  Report on Form 8-K dated July 14,  2003,  as filed with
            the  Securities  and Exchange  Commission on July 14, 2003 (File No.
            000-14879);

      13.   Our Current  Report on Form 8-K,  dated July 15, 2003, as filed with
            the  Securities  and Exchange  Commission on July 15, 2003 (File No.
            000-14879);



                                     - 29 -

<PAGE>


      14.   Our Current  Report on Form 8-K, dated August 1, 2003, as filed with
            the Securities  and Exchange  Commission on August 1, 2003 (File No.
            000-14879);

      15.   Our Current Report on Form 8-K, dated August 14, 2003, as filed with
            the Securities and Exchange  Commission on August 14, 2003 (File No.
            000-14829);

      16.   Our  Quarterly  Report on Form 10-Q for the  period  ended  June 30,
            2003, as filed with the Securities and Exchange Commission on August
            14, 2003 (File No. 000-14879);

      17.   The  description of our common stock  contained in our  Registration
            Statement on Form 8-A, as  supplemented  by the disclosure set forth
            in Exhibit  3.1 to our Form 10-Q  Quarterly  Report for the  quarter
            ended June 30, 2000 and Exhibit 3 to our Form 10-Q Quarterly  Report
            for the quarter ended June 30, 1996 (File No. 000-14879);

      18.   The description of our Series C Junior Participating Preferred Stock
            contained in Exhibit 1 to our Current  Report on Form 8-K filed with
            the  Securities  and Exchange  Commission on June 24, 1998 (File No.
            333-020015); and

      19.   All of our filings  pursuant to the  Exchange  Act after the date of
            filing the initial registration statement and prior to effectiveness
            of the registration statement.

      You may request a copy of these  documents,  which will be provided to you
at  no  cost,  by  writing  or  telephoning  us  using  the  following   contact
information:

                  Cytogen Corporation
                  650 College Road East, 3rd Floor
                  Princeton, New Jersey 08540
                  Attention:  Director, Legal
                  Telephone:  609-750-8222

      You should  rely only on the  information  incorporated  by  reference  or
provided in this prospectus or any prospectus supplement. We have not authorized
anyone  to  provide  you with  information  different  from  that  contained  or
incorporated  by  reference  in this  prospectus.  The  selling  stockholder  is
offering to sell, and seeking offers to buy,  shares of our common stock only in
jurisdictions where offers and sales are permitted. The information contained in
this prospectus is accurate only as of the date of this  prospectus,  regardless
of the time of delivery of this prospectus or of any sale of common stock.


                    INDEMNIFICATION OF DIRECTORS AND OFFICERS

      Subsection  (a) of Section 145 of the  Delaware  General  Corporation  Law
empowers a  corporation  to indemnify  any person who was or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding,
whether civil,  criminal,  administrative or investigative (other than an action
by or in the right of the  corporation)  by reason of the fact that he or she is
or was a director,  officer, employee or agent of the corporation,  or is or was
serving at the request of the  corporation as a director,  officer,  employee or
agent  of  another  corporation,  partnership,  joint  venture,  trust  or other
enterprise,  against expenses (including attorneys' fees), judgments,  fines and
amounts paid in  settlement  actually and  reasonably  incurred by him or her in
connection with such action, suit or proceeding if he or she acted in good faith
and in a manner he or she  reasonably  believed  to be in or not  opposed to the
best interests of the  corporation,  and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his or her conduct was unlawful.



                                     - 30 -

<PAGE>


      Subsection  (b) of Section 145 empowers a  corporation  to  indemnify  any
person  who  was or is a  party  or is  threatened  to be  made a  party  to any
threatened,  pending  or  completed  action  or suit by or in the  right  of the
corporation  to procure a judgment in its favor by reason of the fact that he or
she is or was a director,  officer, employee or agent of the corporation,  or is
or was  serving  at the  request  of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other  enterprise,  against  expenses  (including  attorneys' fees) actually and
reasonably  incurred by him or her in connection  with the defense or settlement
of such  action or suit if he or she  acted in good  faith and in a manner he or
she  reasonably  believed to be in or not opposed to the best  interests  of the
corporation and except that no  indemnification  shall be made in respect of any
claim,  issue or matter as to which such person  shall have been  adjudged to be
liable  to the  corporation  unless  and only to the  extent  that the  Court of
Chancery or the court in which such action or suit was brought  shall  determine
upon application that,  despite the adjudication of liability but in view of all
of the circumstances of the case, such person is fairly and reasonably  entitled
to indemnity for such  expenses  which the Court of Chancery or such other court
shall deem proper.

      Section 145 further provides that to the extent a director or officer of a
corporation has been successful in the defense of any action, suit or proceeding
referred to in subsection  (a) and (b) or in the defense of any claim,  issue or
matter  therein,  he or she shall be  indemnified  against  expenses  (including
attorneys'  fees) actually and  reasonably  incurred by him or her in connection
therewith;  that the indemnification provided by Section 145 shall not be deemed
exclusive  of any other rights to which the  indemnified  party may be entitled;
and that the scope of indemnification extends to directors, officers, employees,
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the  constituent  corporation
for another.  Section 145 also empowers a  corporation  to purchase and maintain
insurance  on behalf of a director  or officer of the  corporation  against  any
liability  asserted  against  him or her or  incurred  by him or her in any such
capacity  or  arising  out of his or her  status  as  such  whether  or not  the
corporation  would  have  the  power  to  indemnify  him  or  her  against  such
liabilities under Section 145.

      Section  102(b)(7)  of the  Delaware  General  Corporation  Law  enables a
corporation in its certificate of incorporation to limit the personal  liability
of members of its board of directors  for  violation  of a director's  fiduciary
duty of care. This section does not, however,  limit the liability of a director
for breaching his or her duty of loyalty, failing to act in good faith, engaging
in intentional misconduct or knowingly violating a law, authorizing a payment of
a dividend or approving a stock  repurchase  in violation of Delaware  Corporate
Law or from any transaction in which the director  derived an improper  personal
benefit.  This  section  also will have no  effect on claims  arising  under the
federal securities laws.

      The Company's  Certificate of  Incorporation  and By-Laws provide that the
Company shall indemnify  officers and directors and, to the extent  permitted by
the Board of Directors,  employees and agents of the Company, to the full extent
permitted  by and in the  manner  permissible  under  the  laws of the  State of
Delaware.  In addition,  the By-Laws  permit the Board of Directors to authorize
the Company to purchase and maintain  insurance  against any director,  officer,
employee or agent of the Company arising out of his capacity as such.

      Cytogen has obtained liability  insurance for the benefit of its directors
and officers  which  provides  coverage for losses of directors and officers for
liabilities  arising out of claims  against such persons  acting as directors or
officers  of  Cytogen  (or any  subsidiary  thereof)  due to any breach of duty,
neglect, error, misstatement, misleading statement, omission or act done by such
directors and officers, except as prohibited by law.

      Insofar as  indemnification  for liabilities  arising under the Securities
Act may be  permitted to  directors,  officers  and  controlling  persons of the
Registrant pursuant to the foregoing  provisions,  or



                                     - 31 -

<PAGE>


otherwise,  the  Registrant has been advised that in the opinion of the SEC such
indemnification  is against public policy as expressed in the Securities Act and
is,  therefore,  unenforceable.  In the event  that a claim for  indemnification
against such  liabilities  (other than the payment by the Registrant of expenses
incurred or paid by a director,  officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as  expressed  in the  Securities  Act and will be  governed by the final
adjudication of such issue.



                                     - 32 -

<PAGE>


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

      The SEC permits us to  "incorporate  by reference" the information we file
with the SEC, which means that we can disclose  important  information to you by
referring to those  documents.  We incorporate by reference the documents listed
below  and any  future  filings  made by us with the SEC under  Sections  13(a),
13(c), 14, and 15(d) of the Securities  Exchange Act of 1934, as amended,  until
the  filing  of a  post-effective  amendment  which  indicates  that all  Shares
registered  here have been sold or which  deregisters  all Shares then remaining
unsold.  The following  documents,  which are on file with the  Commission,  are
incorporated in this registration statement by reference:

      (a) Cytogen's  annual  report filed  pursuant to Section 13(a) or 15(d) of
the Securities Exchange Act of 1934, which includes audited financial statements
for our latest fiscal year for which such statements have been filed.

      (b) All other  reports  filed  pursuant  to Section  13(a) or 15(d) of the
Securities  Exchange Act of 1934 since the end of the fiscal year covered by the
document referred to in (a) above.

      (c) The description of Cytogen's common stock,  $0.01 par value,  which is
contained in our  registration  statement on Form 8-A filed under the Securities
Exchange Act of 1934, as supplemented by the disclosure set forth in Exhibit 3.1
to Cytogen's  Quarterly  Report on Form 10-Q for the quarter ended June 30, 2000
and Exhibit 3 to Cytogen's  Quarterly  Report on Form 10-Q for the quarter ended
June 30, 1996 and  including  any  amendment  or report filed for the purpose of
updating such description.

      All documents  subsequently  filed by the registrant  pursuant to Sections
13(a),  13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the
filing of a post-effective amendment which indicates that all securities offered
hereby have been sold or which deregisters all securities then remaining unsold,
shall be deemed to be incorporated by reference in this  registration  statement
and to be part  hereof  from  the  date of the  filing  of such  documents.  Any
statement  contained in a document  incorporated or deemed to be incorporated by
reference  herein shall be deemed to be modified or superseded  for the purposes
of this registration  statement to the extent that a statement  contained herein
or in any other  subsequently  filed  document  which also is or is deemed to be
incorporated by reference  herein  modifies or supersedes  such  statement.  Any
statement so modified or superseded  shall not be deemed,  except as so modified
or superseded, to constitute a part of this registration statement.

ITEM 4.  DESCRIPTION OF SECURITIES.

      Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

      Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

      Subsection  (a) of Section 145 of the  Delaware  General  Corporation  Law
empowers a  corporation  to indemnify  any person who was or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding,
whether civil,  criminal,  administrative or investigative (other than



                                      II-1

<PAGE>


an action by or in the right of the  corporation)  by reason of the fact that he
or she is or was a director,  officer, employee or agent of the corporation,  or
is or was serving at the  request of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other enterprise, against expenses (including attorneys' fees), judgments, fines
and amounts paid in settlement actually and reasonably incurred by him or her in
connection with such action, suit or proceeding if he or she acted in good faith
and in a manner he or she  reasonably  believed  to be in or not  opposed to the
best interests of the  corporation,  and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his or her conduct was unlawful.

      Subsection  (b) of Section 145 empowers a  corporation  to  indemnify  any
person  who  was or is a  party  or is  threatened  to be  made a  party  to any
threatened,  pending  or  completed  action  or suit by or in the  right  of the
corporation  to procure a judgment in its favor by reason of the fact that he or
she is or was a director,  officer, employee or agent of the corporation,  or is
or was  serving  at the  request  of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other  enterprise,  against  expenses  (including  attorneys' fees) actually and
reasonably  incurred by him or her in connection  with the defense or settlement
of such  action or suit if he or she  acted in good  faith and in a manner he or
she  reasonably  believed to be in or not opposed to the best  interests  of the
corporation and except that no  indemnification  shall be made in respect of any
claim,  issue or matter as to which such person  shall have been  adjudged to be
liable  to the  corporation  unless  and only to the  extent  that the  Court of
Chancery or the court in which such action or suit was brought  shall  determine
upon application that,  despite the adjudication of liability but in view of all
of the circumstances of the case, such person is fairly and reasonably  entitled
to indemnity for such  expenses  which the Court of Chancery or such other court
shall deem proper.

      Section 145 further provides that to the extent a director or officer of a
corporation has been successful in the defense of any action, suit or proceeding
referred to in subsection  (a) and (b) or in the defense of any claim,  issue or
matter  therein,  he or she shall be  indemnified  against  expenses  (including
attorneys'  fees) actually and  reasonably  incurred by him or her in connection
therewith;  that the indemnification provided by Section 145 shall not be deemed
exclusive  of any other rights to which the  indemnified  party may be entitled;
and that the scope of indemnification extends to directors, officers, employees,
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the  constituent  corporation
for another.  Section 145 also empowers a  corporation  to purchase and maintain
insurance  on behalf of a director  or officer of the  corporation  against  any
liability  asserted  against  him or her or  incurred  by him or her in any such
capacity  or  arising  out of his or her  status  as  such  whether  or not  the
corporation  would  have  the  power  to  indemnify  him  or  her  against  such
liabilities under Section 145.

      Section  102(b)(7)  of the  Delaware  General  Corporation  Law  enables a
corporation in its certificate of incorporation to limit the personal  liability
of members of its board of directors  for  violation  of a director's  fiduciary
duty of care. This section does not, however,  limit the liability of a director
for breaching his or her duty of loyalty, failing to act in good faith, engaging
in intentional misconduct or knowingly violating a law, authorizing a payment of
a dividend or approving a stock  repurchase  in violation of Delaware  Corporate
Law or from any transaction in which the director  derived an improper  personal
benefit.  This  section  also will have no  effect on claims  arising  under the
federal securities laws.

      The Company's  Certificate of  Incorporation  and By-Laws provide that the
Company shall indemnify  officers and directors and, to the extent  permitted by
the Board of Directors,  employees and agents of the Company, to the full extent
permitted  by and in the  manner  permissible  under  the  laws of the  State of
Delaware.  In addition,  the By-Laws  permit the Board of Directors to authorize
the Company



                                      II-2

<PAGE>


to purchase and maintain  insurance against any director,  officer,  employee or
agent of the Company arising out of his capacity as such.

      Cytogen has obtained liability  insurance for the benefit of its directors
and officers  which  provides  coverage for losses of directors and officers for
liabilities  arising out of claims  against such persons  acting as directors or
officers  of  Cytogen  (or any  subsidiary  thereof)  due to any breach of duty,
neglect, error, misstatement, misleading statement, omission or act done by such
directors and officers, except as prohibited by law.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

      The  issuance of the Shares  being  reoffered  or resold  pursuant to this
Registration Statement were or will be deemed exempt from registration under the
Securities  Act in reliance upon either  Section 4(2) of the  Securities  Act as
transactions  not involving any public offering or Rule 701 under the Securities
Act as transactions made pursuant to a written  compensatory plan or pursuant to
a written contract relating to compensation.

ITEM 8.  EXHIBITS.

 Exhibit Number                            Description
 --------------   --------------------------------------------------------------

      5.1         Opinion of Hale and Dorr LLP.

      10.1        1995 Stock Option Plan,  as amended,  filed with the SEC as an
                  exhibit to the Company's Form 10-K for the year ended December
                  31, 2002, as amended, and incorporated herein by reference.

      23.1        Consent of KPMG LLP.

      23.2        Consent of PricewaterhouseCoopers LLP.

      23.3        Consent of Hale and Dorr LLP  (contained  in the opinion filed
                  as Exhibit 5.1).

      24          Power of Attorney  (contained  on the  signature  page of this
                  Registration Statement).

ITEM 9.  UNDERTAKINGS.

      a. Cytogen hereby undertakes:

            (1) To file,  during any  period in which  offers or sales are being
      made, a post-effective amendment to this registration statement:

            (i)   To include any prospectus  required by Section 10(a)(3) of the
                  Securities Act;

            (ii)  To reflect in the prospectus any facts or events arising after
                  the effective date of this registration statement (or the most
                  recent post-effective  amendment thereof) which,  individually
                  or in the  aggregate,  represent a  fundamental  change in the
                  information set forth in the registration statement; and



                                      II-3

<PAGE>


            (iii) To include any material  information  with respect to the plan
                  of distribution not previously  disclosed in this registration
                  statement or any material  change to such  information in this
                  registration statement;

      provided,  however,  that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
      if the information  required to be included in a post-effective  amendment
      by those  paragraphs  is  contained  in  periodic  reports  filed  with or
      furnished to the SEC by Cytogen pursuant to Section 13 or Section 15(d) of
      the Exchange Act that are  incorporated by reference in this  registration
      statement.

            (2) That,  for the purpose of  determining  any liability  under the
      Securities Act, each such post-effective amendment shall be deemed to be a
      new registration statement relating to the securities offered therein, and
      the  offering  of such  securities  at that time shall be deemed to be the
      initial bona fide offering thereof.

            (3)  To  remove  from  registration  by  means  of a  post-effective
      amendment any of the securities  being  registered  which remain unsold at
      the termination of the offering.

      b. The  undersigned  Registrant  hereby  undertakes  that, for purposes of
determining  any  liability  under  the  Securities  Act,  each  filing  of  the
Registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Exchange Act (and, where  applicable,  each filing of an employee benefit plan's
annual  report   pursuant  to  Section  15(d)  of  the  Exchange  Act)  that  is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration  statement relating to the securities offered therein,  and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

      c. Insofar as indemnification for liabilities arising under the Securities
Act may be  permitted to  directors,  officers  and  controlling  persons of the
Registrant pursuant to the foregoing  provisions,  or otherwise,  the Registrant
has been advised that in the opinion of the SEC such  indemnification is against
public  policy  as  expressed  in  the   Securities   Act  and  is,   therefore,
unenforceable.  In the  event  that a claim  for  indemnification  against  such
liabilities  (other than the payment by the  Registrant of expenses  incurred or
paid by a  director,  officer or  controlling  person of the  Registrant  in the
successful  defense of any  action,  suit or  proceeding)  is  asserted  by such
director,  officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as  expressed  in the  Securities  Act and will be  governed by the final
adjudication of such issue.



                                      II-4

<PAGE>


                                   SIGNATURES

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Registration  Statement  on  Form  S-8  to  be  signed  on  its  behalf  by  the
undersigned,  thereunto duly authorized, in the City of Princeton,  State of New
Jersey, on October 24, 2003.

                                    CYTOGEN CORPORATION


                                    By:  /s/ Michael D. Becker
                                       -----------------------------------------
                                       Michael D. Becker
                                       President and Chief Executive Officer

<PAGE>


                        SIGNATURES AND POWER OF ATTORNEY

      We, the undersigned officers and directors of Cytogen Corporation,  hereby
severally constitute and appoint Michael D. Becker and Christopher P. Schnittker
and each of them singly, our true and lawful attorneys with full power to any of
them,  and to each of  them  singly,  to  sign  for us and in our  names  in the
capacities  indicated  below,  the  Registration  Statement  on Form  S-8  filed
herewith and any and all  pre-effective  and  post-effective  amendments to said
Registration  Statement  and  generally  to do all such  things  in our name and
behalf in our capacities as officers and directors to enable Cytogen Corporation
to comply with the provisions of the Securities Act of 1933, as amended, and all
requirements  of the Securities and Exchange  Commission,  hereby  ratifying and
confirming our signatures as they may be signed by our said attorneys, or any of
them, to said Registration Statement and any and all amendments thereto.

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
this  Registration  Statement  has been signed by the  following  persons in the
capacities and on the dates indicated.

           Signature                          Title                     Date
-------------------------------  -----------------------------  ----------------

/s/ Michael D. Becker            President, Chief Executive     October 24, 2003
-------------------------------  Officer and Director
Michael D. Becker                (Principal
                                 Executive Officer)

/s/ Christopher P. Schnittker    Vice President and Chief       October 24, 2003
-------------------------------  Financial   Officer
Christopher P. Schnittker        (Principal Financial and
                                 Accounting Officer)

/s/ John E. Bagalay, Jr.         Director                       October 24, 2003
-------------------------------
John E.  Bagalay, Jr.

/s/ Allen Bloom                  Director                       October 24, 2003
-------------------------------
Allen Bloom

                                 Director
-------------------------------
Stephen K.  Carter

/s/ James A. Grigsby             Director                       October 24, 2003
-------------------------------
James A. Grigsby

                                 Director
-------------------------------
Robert F.  Hendrickson


/s/ Kevin G. Lokay               Director                       October 24, 2003
-------------------------------
Kevin G. Lokay

/s/ H. Joseph Reiser             Director                       October 24, 2003
-------------------------------
H. Joseph Reiser


<PAGE>


                                  EXHIBIT INDEX


  Exhibit Number                            Description
 --------------   --------------------------------------------------------------

      5.1         Opinion of Hale and Dorr LLP.

      10.1        1995 Stock Option Plan,  as amended,  filed with the SEC as an
                  exhibit to the Company's Form 10-K for the year ended December
                  31, 2002, as amended, and incorporated herein by reference.

      23.1        Consent of KPMG LLP.

      23.2        Consent of PricewaterhouseCoopers LLP.

      23.3        Consent of Hale and Dorr LLP  (contained  in the opinion filed
                  as Exhibit 5.1).

      24          Power of Attorney  (contained  on the  signature  page of this
                  Registration Statement).
[{"type": "S-8", "sequence": "1", "filename": "forms8_1003.txt", "description": "CYTOGEN CORPORATION", "secsgml_size_bytes": 142087}]
{"company-data": {"conformed-name": "CYTOGEN CORP", "cik": "0000725058", "assigned-sic": "2835", "irs-number": "222322400", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-109986", "film-number": "03957113"}, "business-address": {"street1": "600 COLLEGE RD EAST CN 5308", "city": "PRINCETON", "state": "NJ", "zip": "08540", "phone": "6099878200"}, "mail-address": {"street1": "600 COLLEGE RD EAST CN 5308", "street2": "600 COLLEGE RD EAST CN 5308", "city": "PRINCETON", "state": "NJ", "zip": "08540"}}
As filed with the Securities and Exchange Commission on October 24, 2003
                                                    Registration No. 333-

--------------------------------------------------------------------------------

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                               ---------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                               CYTOGEN CORPORATION
--------------------------------------------------------------------------------
             (Exact Name of Registrant as Specified in its Charter)

                               650 College Road East, Suite
         Delaware           3100, Princeton, New Jersey 08540     22-2322400
-----------------------    ----------------------------------  -----------------
   (State or Other              (Address of Principal          (I.R.S. Employer
   Jurisdiction of              Executive Offices)             Identification
   Incorporation or                 (Zip Code)                       No.)
   Organization)

                       1995 Stock Option Plan, as amended
                          January 2001 Option Agreement
--------------------------------------------------------------------------------
                            (Full Title of the Plans)

                            Donald L. Novajosky, Esq.
                                 Director, Legal
                               Cytogen Corporation
                        650 College Road East, Suite 3100
                           Princeton, New Jersey 08540
--------------------------------------------------------------------------------
                              (Name and Address of
                               Agent for Service)

                                 (609) 750-8222
--------------------------------------------------------------------------------
                     (Telephone Number, Including Area Code,
                              of Agent For Service)

                                    Copy To:

                           Richard S. Mattessich, Esq.
                                Hale and Dorr LLP
                              650 College Road East
                               Princeton, NJ 08540
                                 (609) 750-7600
CALCULATION OF REGISTRATION FEE

=========================================================================================
                                                  Proposed
                                                  Maximum       Proposed
                                        Amount    Offering       Maximum      Amount Of
         Title Of Securities             To Be    Price Per     Aggregate    Registration
          To Be Registered            Registered    Share    Offering Price      Fee
                                          (1)
-----------------------------------------------------------------------------------------
Common Stock, par value $.01 per
share:
Shares to be issued pursuant to        46,319     $10.37(2)  $  480,328(2)   $ 38.86
     prior option grants under the
     1995 Stock Option
     Plan..........................
  Shares to be issued pursuant to
     future option grants under the
     1995 Stock Option
     Plan..........................     153,681     $11.27(3)  $1,731,985(3)   $140.12
  Shares to be issued pursuant to
     prior option grants under the
     January 2001 Option Agreement.       1,000     $61.255(4) $   61,255(4)   $  4.96
-----------------------------------------------------------------------------------------
     TOTAL.........................     201,000                $2,273,568      $183.93
=========================================================================================
(1)   For the sole purpose of calculating  the  registration  fee, the number of
      shares to be registered under this Registration Statement has been divided
      among three (3) subtotals.

(2)   Pursuant to Rule 457(h),  these prices are calculated  based on a weighted
      average  exercise price of $10.37 per share covering 46,319 shares subject
      to stock options granted under the 1995 Stock Option Plan.

(3)   Pursuant to Rule 457(h) and Rule 457(c), these prices are estimated solely
      for the purpose of calculating the registration fee and are based upon the
      average of the high and low prices of the  Company's  Common  Stock on the
      Nasdaq National Market on October 22, 2003.

(4)   Pursuant to Rule 457(h), these prices are calculated based on the exercise
      price of $61.255 per share  covering 1,000 shares subject to stock options
      granted under the January 2001 Option Agreement.

      In addition,  pursuant to Rule 416 under the  Securities  Act of 1933,  as
amended,  this  Registration  Statement also covers an  indeterminate  number of
shares as may be issued as a result of the anti-dilution and similar  provisions
of the 1995 Stock Option Plan and the January 2001 Option Agreement.

                                 ---------------

                                       ii
Explanatory Note

      The documents containing the information  specified in the instructions to
Part I of Form S-8 will be sent or given to participants of Cytogen's 1995 Stock
Option Plan, as amended,  as required by Rule 428(b)(1) of the Securities Act of
1933. As permitted by the  instructions  to Part I of Form S-8, these  documents
are not filed with this registration statement.  Pursuant to General Instruction
E of Form  S-8,  Cytogen  hereby  incorporates  by  reference  the  Registration
Statement on Form S-8 previously filed by the Registrant with the Securities and
Exchange  Commission  on October  10, 1995 (File No.  033-63321),  as amended by
filings on May 29, 1996 (File No.  333-04679)  and on October 18, 2000 (File No.
333-27673) in connection with the 1995 Stock Option Plan.

      This  registration  statement  contains a reoffer  prospectus  prepared in
accordance  with the  requirements of Part I of Form S-3 with respect to options
to purchase 1,000 shares of Common Stock granted to an affiliate pursuant to the
January  2001  Option  Agreement.  Such  individual  is  listed  on the  Selling
Shareholder Table herein.

      This  registration  statement also contains  "Information  Required in the
Registration  Statement" prepared in accordance with the requirements of Part II
of Form S-8 with respect to options to purchase  200,000  shares of Common Stock
granted  pursuant to Cytogen's 1995 Stock Option Plan, as amended,  prior to the
date hereof, and that may be granted subsequent to the date hereof. Such 200,000
shares of Common Stock relate to a previously approved increase in the number of
shares of Common Stock  authorized  for issuance upon the exercise of options to
be granted under Cytogen's 1995 Stock Option Plan.

                                      iii
PROSPECTUS

                  S-3 Reoffer Prospectus dated October 24, 2003

                               CYTOGEN CORPORATION

                          1,000 Shares of Common Stock
                Issuable under the January 2001 Option Agreement

      This  Prospectus  relates to the public  resale,  from time to time, of an
aggregate of 1,000 shares (the  "Shares")  of our Common  Stock,  $.01 par value
(the "Common Stock") by that certain shareholder identified below in the section
entitled  "The  Selling  Shareholder."  These  Shares may be  acquired  upon the
exercise of stock options granted outside of any of our option plans.

      We will not  receive  any of the  proceeds  from  the sale by the  Selling
Shareholder of the Shares covered by this Prospectus.

      We have not entered into any underwriting  arrangements in connection with
the sale of  Shares.  The  Shares  may be sold from time to time by the  Selling
Shareholder or by permitted  pledgees,  donees,  transferees or other  permitted
successors in interest and may be made on the Nasdaq  National  Market at prices
and at terms then  prevailing  or at prices  related to the then current  market
price, or in negotiated transactions.

      Our Common Stock is traded on the Nasdaq  National Market under the symbol
"CYTO." On October 22,  2003,  the closing sale price of our Common Stock on the
Nasdaq National Market was $11.16 per share.

      INVESTING  IN THE COMMON STOCK  INVOLVES A HIGH DEGREE OF RISK.  SEE "RISK
FACTORS" BEGINNING ON PAGE 5.

      NEITHER THE  SECURITIES AND EXCHANGE  COMMISSION NOR ANY STATE  SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS  IS TRUTHFUL OR  COMPLETE.  ANY  REPRESENTATION  TO THE CONTRARY IS A
CRIMINAL OFFENSE.

                The date of this Prospectus is October 24, 2003.
TABLE OF CONTENTS
--------------------------------------------------------------------------------
Cytogen Corporation....................................................     3
Reverse Stock Split....................................................     4
Risk Factors...........................................................     5
      We  have a  history  of  operating  losses  and an  accumulated
        deficit and expect to incur losses in the future...............     5
      We  depend  on  sales  of  ProstaScint  and  Quadramet  for the
        majority of our near-term revenues.............................     6
      We  depend  on  acceptance  of  our  products  by  the  medical
        community for the continuation of our revenues.................     6
      The reduced  workforce  at AxCell may not be able to  implement
        AxCell's business plan.........................................     7
      We may  need to  raise  additional  capital,  which  may not be
        available......................................................     7
      Our capital raising efforts may dilute stockholder interests.....     8
      We may need to raise funds other than  through the  issuance of
        equity securities..............................................     8
      Our   products,   generally,   are  in  the  early   stages  of
        development  and  commercialization  and we may never achieve
        the revenue goals set forth in our business plan...............     8
      Our  PSMA   product   development   program   is   novel   and,
        consequently, inherently risky.................................     9
      All of our potential  oncology  products will be subject to the
        risks of failure  inherent in the  development  of diagnostic
        or therapeutic products based on new technologies..............     9
      Competition in our field is intense and likely to increase.......    10
      We rely heavily on our collaborative partners....................    11
      Our business  could be harmed if certain  agreements  expire or
        are terminated early...........................................    12
      We have limited sales, marketing and distribution  capabilities
        for our products...............................................    13
      There are risks  associated  with the manufacture and supply of
        our products...................................................    14
      Failure of  consumers  to obtain  adequate  reimbursement  from
        third-party  payors could limit market  acceptance and affect
        pricing of our products........................................    14
      If  we  are  unable  to  comply  with  applicable  governmental
        regulation we may not be able to continue our operations.......    15
      We could be  negatively  impacted by future  interpretation  or
        implementation  of federal  and state  fraud and abuse  laws,
        including  anti-kickback  laws,  the  Federal  Stark  Law and
        other federal and state anti-referral laws.....................    16
      We depend on attracting and retaining key personnel..............    17
      Our business exposes us to potential  liability claims that may
        exceed  our  financial  resources,  including  our  insurance
        coverage,  and may lead to the  curtailment or termination of
        our operations.................................................    18
      Our business  involves  environmental  risks that may result in
        liability......................................................    18
      Our intellectual property is difficult to protect................    19
      Our   security   measures   may  not  protect  our   unpatented
        proprietary technology.........................................    20
      We are currently subject to patent litigation....................    20
      Our stock price has been and may continue to be  volatile,  and
        your  investment  in our  stock  could  decline  in  value or
        fluctuate significantly........................................    21
--------------------------------------------------------------------------------

                                      - i -
TABLE OF CONTENTS
--------------------------------------------------------------------------------
      We have  adopted  various  anti-takeover  provisions  which may
        affect the market  price of our common  stock and  prevent or
        frustrate  attempts by our  stockholders to replace or remove
        our management team............................................    22
      The  liquidity of our common stock could be adversely  affected
        if we are delisted from The Nasdaq National Market.............    22
      A large  number of our shares  are  eligible  for  future  sale
        which may  adversely  impact the  market  price of our common
        stock..........................................................    23
      Because  we do not intend to pay,  and have not paid,  any cash
        dividends  on our shares of common  stock,  our  stockholders
        will not be able to receive a return on their  shares  unless
        the value of our shares appreciates and they sell them.........    24
Special Note Regarding Forward-Looking Statements......................    25
Use of Proceeds........................................................    25
Selling Shareholder....................................................    26
Plan of Distribution...................................................    27
Legal Matters..........................................................    28
Experts................................................................    28
Where You Can Find More Information....................................    28
Information Incorporated By Reference..................................    29
Indemnification of Officers and Directors..............................    30
--------------------------------------------------------------------------------

                                     - ii -
CYTOGEN CORPORATION

      Cytogen     Corporation    is    a    product-driven,     oncology-focused
biopharmaceutical  company  with an  established  and  growing  product  line in
prostate cancer and other areas of oncology.  Our FDA-approved  products include
ProstaScint(R)  (a  monoclonal  antibody-based  imaging  agent used to image the
extent  and  spread of  prostate  cancer);  Quadramet(R)  (a  therapeutic  agent
marketed  for the relief of bone pain in prostate and other types of cancer) and
NMP22  BladderChek(TM)  (a  point-of-care,  in vitro diagnostic test for bladder
cancer).  Our pipeline is comprised of product  candidates at various  stages of
clinical  development,  including fully human  monoclonal  antibodies and cancer
vaccines based on PSMA prostate  specific membrane antigen  technology,  or PSMA
technologies, which we exclusively licensed from Memorial Sloan-Kettering Cancer
Center.  We also conduct research in cellular  signaling through our subsidiary,
AxCell Biosciences.

      In addition to the products listed above, in August, 2000, we expanded our
product pipeline by entering into marketing,  license and supply agreements with
Advanced Magnetics,  Inc. for Combidex(R),  which is an investigational magnetic
resonance  imaging (MRI) contrast agent that assists in the  differentiation  of
metastatic from  non-metastatic  lymph nodes. We hold exclusive marketing rights
to Combidex in the United  States and its  territories.  Advanced  Magnetics  is
continuing its discussions with the FDA relating to outstanding issues regarding
an approvable  letter received from the FDA in June, 2000, in an effort to bring
Combidex to market.

      We have had a history of operating  losses since our  inception.  We had a
net loss of $3.4 million for the three months ended June 30, 2003, a net loss of
$5.3  million  for the six months  ended  June 30,  2003 and a net loss of $15.7
million for the year ended December 31, 2002.  Although we  continually  look to
expand our product pipeline, we currently rely on two products,  ProstaScint and
Quadramet,  for  substantially all of our revenues.  In addition,  we have, from
time to time, ceased sales of certain products, such as BrachySeed and OncoScint
CR/OV, that we previously believed would generate  significant  revenues for our
business.  Our products are subject to significant  regulatory review by the FDA
and other  federal  and state  agencies,  which  requires  significant  time and
expenditures in seeking product approvals. In addition, we rely on collaborative
partners to a significant  degree to  manufacture  our  products,  to secure raw
materials,  and to provide licensing rights to their proprietary products for us
to sell and market to others.

      We are a Delaware  corporation.  We were incorporated and began operations
in 1980  under  the  name  Hybridex,  Inc.  and  changed  our  name  to  Cytogen
Corporation in April 1980. Our executive offices are located at 650 College Road
East,  Suite 3100,  Princeton,  New Jersey 08540,  our telephone number is (609)
750-8200 and our Internet address is  http://www.cytogen.com  The information on
our Internet website is not incorporated by reference in this prospectus. Unless
the context otherwise requires  references in this prospectus to "Cytogen",  the
"Company,"  "we,"  "us,"  and  "our"  refer  to  Cytogen   Corporation  and  our
subsidiaries.

      ProstaScint(R) and OncoScint(R) are registered United States trademarks of
Cytogen  Corporation.  All  other  trade  names,  trademarks  or  service  marks
appearing in this  Registration  Statement on Form S-3 are the property of their
respective  owners,  and not the property of Cytogen  Corporation  or any of our
subsidiaries. Quadramet(R) is a trademark of The Dow Chemical Company used under
license by Cytogen.

                                     - 3 -
REVERSE STOCK SPLIT

      On October 25, 2002, we received  approval from our stockholders at a duly
called and held special meeting of stockholders to effect a reverse split of our
common stock. Our Board of Directors  thereafter  approved a one-for-ten reverse
split of our outstanding,  issued and authorized  shares of common stock,  which
became effective on October 25, 2002. All numbers set forth in this Registration
Statement  on Form S-3  reflect  the effect of such  one-for-ten  reverse  stock
split.

                                     - 4 -
RISK FACTORS

      Investing in our common stock  involves a high degree of risk.  You should
carefully consider the risks and uncertainties described below before purchasing
our common stock. If any of the following  risks actually  occur,  our business,
financial  condition or results of operations would likely suffer. In that case,
the trading  price of our common stock could fall,  and you may lose all or part
of the money you paid to buy our common stock.

WE HAVE A HISTORY OF OPERATING  LOSSES AND AN ACCUMULATED  DEFICIT AND EXPECT TO
INCUR LOSSES IN THE FUTURE.

Given the high  level of  research  and  development  and  related  expenditures
associated with our business and our inability to generate  revenues  sufficient
to cover such expenditures,  we have had a history of operating losses since our
inception. We had a net loss of $3.4 million for the three months ended June 30,
2003,  a net loss of $5.3  million for the six months  ended June 30, 2003 and a
net loss of $15.7  million for the year ended  December 31,  2002.  Beginning in
December  2001,  we began to  equally  share the  costs of the PSMA  Development
Company  LLC and we  expect to incur  significant  and  increasing  costs in the
future  to fund  our  share  of the  joint  venture.  We had a net loss of $12.1
million for the year ended December 31, 2001. We had a net loss of $27.3 million
for the year ended  December 31, 2000 which included  non-cash  charges of $13.1
million for the acquisition of product candidate rights and $4.3 million for the
cumulative  effect of an accounting  change following the adoption of Securities
and Exchange Commission Staff Accounting Bulletin No. 101. We had an accumulated
deficit of $361.7 million as of June 30, 2003.

In order  to  develop  and  commercialize  our  technologies,  particularly  our
prostate specific membrane antigen, or PSMA, technology, and expand our oncology
products, we expect to incur significant increases in our expenses over the next
several  years.  As a result,  we will need to generate  significant  additional
revenue to become profitable.

To date,  we have  taken  affirmative  steps to reduce  our  trend of  operating
losses. Such steps include, among other things: (i) the effective monitoring and
management  of  expenses  relating  to  research  and  development,  selling and
marketing,  and other general and administrative  matters; (ii) undergoing steps
to  realign  and  implement  our  focus  as a  product-driven,  oncology-focused
biopharmaceutical  company;  (iii)  the  establishment  and  maintenance  of our
in-house  specialty sales force;  (iv) enhancing our marketed product  portfolio
through marketing alliances and strategic arrangements such as we have done with
the Combidex  product,  which we intend to market if this product is approved by
the FDA; (v) the  reacquisition  of North American and Latin American  marketing
rights to  Quadramet  from  Berlex  Laboratories  in August  2003;  and (vi) the
addition of NMP22 BladderChek to our marketed product portfolio.

Although  we  have  taken  these  affirmative  steps,  we may  never  be able to
successfully implement them, and our ability to generate and sustain significant
additional  revenues  or achieve  profitability  will  depend  upon the  factors
discussed  elsewhere in this "Risk Factors"  section,  as well as numerous other
factors outside of our control, including:

o     development  of  competing  products  that  are more  effective  or less
      costly than ours;

o     our  ability  to  develop  and   commercialize   our  own  products  and
      technologies; and

o     our ability to achieve  increased  sales for our  existing  products and
      sales for any new products.

                                     - 5 -
As a result, we may never be able to generate or sustain significant  additional
revenue or achieve profitability.

WE  DEPEND  ON  SALES OF  PROSTASCINT  AND  QUADRAMET  FOR THE  MAJORITY  OF OUR
NEAR-TERM REVENUES.

We expect  ProstaScint and Quadramet to account for a significant  percentage of
our product related revenues in the near future. For the year ended December 31,
2002,  revenues from  ProstaScint  and royalties  from  Quadramet  accounted for
approximately 64% and 15%, respectively, of our product related revenues; and in
the six months ended June 30, 2003, revenues from ProstaScint and royalties from
Quadramet accounted for approximately 72% and 20%, respectively,  of our product
related  revenues.  If  ProstaScint  or Quadramet do not achieve  broader market
acceptance,  either because we fail to  effectively  market such products or our
competitors  introduce  competing  products,  we may  not be  able  to  generate
sufficient  revenue to become  profitable.  In 2002, our product related revenue
included revenue from BrachySeed, which accounted for 20% of our product related
revenue.  In  January  2003,  we served  notice of  termination  for each of our
License  and  Distribution   Agreement  and  Product  Manufacturing  and  Supply
Agreement  with  Draximage  with  respect  to  both  the  BrachySeed  I-125  and
BrachySeed  Pd-103  products.  As a result,  effective  January 24, 2003,  we no
longer accept or fill new orders for the BrachySeed products.  In April 2003, we
entered into an agreement  with  Draximage  formally  terminating  each of these
agreements.

Generating  market  acceptance  and sales of our  products  is  difficult,  time
consuming and uncertain.  We launched  ProstaScint in October 1996, Quadramet in
March 1997, OncoScint CR/OV in December 1992, BrachySeed I-125 in February 2001,
BrachySeed Pd-103 in May 2002 and NMP22  BladderChek in November 2002.  Revenues
for  ProstaScint  grew from $55,000 in 1996 to $7.9  million in 2002.  Royalties
from sales of Quadramet  went from $3.3 million in 1997 to $1.8 million in 2002.
Royalties  from sales of Quadramet in the initial years of sales were  supported
by a guaranteed  minimum  revenue  arrangement  with the third party licensor of
Quadramet.  OncoScint CR/OV selling  activity was  discontinued in December 2002
and selling activities for the BrachySeed  products were discontinued in January
2003. NMP22  BladderChek is a relatively new product for us.  Currently,  all of
our  revenues  are  derived  from  sales of  ProstaScint,  Quadramet  and  NMP22
BladderChek products, as well as certain license and contract revenues.

WE DEPEND  ON  ACCEPTANCE  OF OUR  PRODUCTS  BY THE  MEDICAL  COMMUNITY  FOR THE
CONTINUATION OF OUR REVENUES.

Because our marketed  products  contribute  the majority of our product  related
revenues, our business,  financial condition and results of operations depend on
their  acceptance as safe,  effective and  cost-efficient  alternatives to other
available   treatment  and  diagnostic   protocols  by  the  medical  community,
including:

o     health care providers, such as hospitals and physicians; and

o     third-party  payors,  including  Medicare,  Medicaid,  private insurance
      carriers and health maintenance organizations.

Our  customers,   including  technologists  and  physicians,  must  successfully
complete our Partners in  Excellence  Program,  or PIE  Program,  a  proprietary
training program designed to promote the correct  acquisition and interpretation
of  ProstaScint  images.  This  product is  technique  dependent  and requires a
learning commitment by technologists and physicians and their acceptance of this
product as part of their treatment practices. If ProstaScint or Quadramet do not
achieve  broader market  acceptance,  we may not be able to generate  sufficient
revenue to become profitable.

                                     - 6 -
THE REDUCED  WORKFORCE AT AXCELL MAY NOT BE ABLE TO IMPLEMENT  AXCELL'S BUSINESS
PLAN.

In September 2002, we implemented the  restructuring  of our subsidiary,  AxCell
Biosciences  Corporation,  in an effort to reduce expenses and position  Cytogen
for stronger long-term growth in oncology.  As a result, we reduced our staff at
AxCell by  seventy-five  percent,  suspended  certain  projects  at  AxCell  and
implemented other cost-saving measures.

The technologies under development at AxCell are complex and remain commercially
unproven.  Even if we are able to develop and  commercialize  a product  through
AxCell,  there may be fewer than 100 pharmaceutical  companies and biotechnology
companies that are potential customers for such technology or product.

Although we believe that we have  retained the AxCell  personnel  who are key to
achieving AxCell's goals and implementing its strategies, such reduced workforce
may not be able to implement AxCell's current business plan. The further loss of
any of  AxCell's  personnel  could have a material  adverse  effect on  AxCell's
ability to achieve its goals.

WE MAY NEED TO RAISE ADDITIONAL CAPITAL, WHICH MAY NOT BE AVAILABLE.

Our cash and cash equivalents  were $13.5 million as of June 30, 2003,  compared
to $14.7  million as of December 31, 2002.  We expect that our existing  capital
resources  should be adequate to fund our  operations and  commitments  into the
second half of 2004.

We have  incurred  negative cash flows from  operations  since our inception and
have expended, and expect to continue to expend in the future, substantial funds
based upon the:

o     success of our product commercialization efforts;

o     success  of  any  future   acquisitions  of  complementary   products  and
      technologies we may make;

o     magnitude,  scope and results of our product  development and research and
      development efforts;

o     progress of preclinical studies and clinical trials;

o     progress toward regulatory approval for our products;

o     costs of filing,  prosecuting,  defending and enforcing  patent claims and
      other intellectual property rights;

o     competing technological and market developments; and

o     expansion of strategic alliances for the sale,  marketing and distribution
      of our products.

Our business or operations  may change in a manner that would consume  available
resources more rapidly than anticipated.  We expect that we will have additional
requirements  for debt or equity  capital,  irrespective  of whether and when we
reach  profitability,   for  further  product  development  costs,  product  and
technology  acquisition  costs,  and  working  capital.  To the extent  that the
currently  available  funds and  revenues  are  insufficient  to meet current or
planned operating  requirements,  we will be required to obtain additional funds
through equity or debt financing,  strategic  alliances with corporate  partners
and  others,  or through  other  sources.  These  financial  sources  may not be
available when we need them or they may be available,  but on terms that are not
commercially  acceptable to us. If adequate funds are not  available,  we

                                     - 7 -
may be required to delay, further scale back or eliminate certain aspects of our
operations or attempt to obtain funds through  arrangements  with  collaborative
partners or others that may  require us to  relinquish  rights to certain of our
technologies,  product  candidates,  products or potential markets.  If adequate
funds are not  available,  our  business,  financial  condition  and  results of
operations will be materially and adversely affected.

OUR CAPITAL RAISING EFFORTS MAY DILUTE STOCKHOLDER INTERESTS.

If we raise additional capital by issuing equity  securities,  the issuance will
result in ownership  dilution to our existing  stockholders.  The extent of such
dilution will vary based upon the amount of capital raised.

WE MAY NEED TO RAISE FUNDS OTHER THAN THROUGH THE ISSUANCE OF EQUITY SECURITIES.

If we raise additional funds through collaborations and licensing  arrangements,
we may be  required  to  relinquish  rights to  certain of our  technologies  or
product  candidates or to grant licenses on unfavorable  terms. If we relinquish
rights or grant licenses on unfavorable  terms, we may not be able to develop or
market products in a manner that is profitable to us.

OUR  PRODUCTS,   GENERALLY,   ARE  IN  THE  EARLY  STAGES  OF  DEVELOPMENT   AND
COMMERCIALIZATION  AND WE MAY NEVER  ACHIEVE THE REVENUE  GOALS SET FORTH IN OUR
BUSINESS PLAN.

We began operations in 1980 and have been engaged primarily in research directed
toward the development,  commercialization  and marketing of products to improve
diagnosis  and  treatment of cancer and other  diseases.  In December  1992,  we
introduced  OncoScint CR/OV, and subsequently  ceased selling and marketing this
product in December  2002. In October 1996, we introduced for commercial use our
ProstaScint  imaging agent.  In March 1997, we introduced for commercial use our
Quadramet  therapeutic  product.  In 2001,  we  launched  the iodine  version of
BrachySeed.  In May 2002, we launched the palladium  version of  BrachySeed.  In
January 2003, we discontinued our marketing and sale of the BrachySeed products.
In November  2002, we began  promoting  NMP22  BladderChek  to urologists in the
United States.

Our PSMA  technologies  are still in the early  stages of  development.  We have
significantly reduced operations at our AxCell subsidiary,  which is responsible
for the development certain of our technologies.  We may be unable to develop or
commercialize these products and technologies.

Our business is therefore subject to the risks inherent in the development of an
early stage biopharmaceutical business enterprise, such as the need:

o     to obtain  sufficient  capital to support the expenses of  developing  our
      technology and commercializing our products;

o     to ensure that our products are safe and effective;

o     to obtain regulatory approval for the use and sale of our products;

o     to manufacture  our products in sufficient  quantities and at a reasonable
      cost;

o     to develop a sufficient market for our products; and

o     to  attract  and  retain  qualified  management,   sales,   technical  and
      scientific staff.

                                     - 8 -
The problems  frequently  encountered  using new technologies and operating in a
competitive  environment  also may affect our  business.  If we fail to properly
address these risks and attain our business  objectives,  our business  could be
significantly and adversely affected.

OUR PSMA  PRODUCT  DEVELOPMENT  PROGRAM IS NOVEL AND,  CONSEQUENTLY,  INHERENTLY
RISKY.

We are subject to the risks of failure  inherent in the  development  of product
candidates based on new technologies, including our PSMA technology. These risks
include the possibility that:

o     the technologies we use will not be effective;

o     our product candidates will be unsafe;

o     our  product  candidates  will fail to receive  the  necessary  regulatory
      approvals;

o     the product  candidates  will be hard to  manufacture  on a large scale or
      will be uneconomical to market; and

o     we will not successfully  overcome  technological  challenges presented by
      our potential new products.

Our other research and development  programs involve  similarly novel approaches
to human  therapeutics.  Consequently,  there is no precedent for the successful
commercialization of therapeutic products based on our PSMA technologies.  If we
fail to develop such products, our business could be significantly and adversely
affected.

ALL OF OUR POTENTIAL  ONCOLOGY  PRODUCTS WILL BE SUBJECT TO THE RISKS OF FAILURE
INHERENT IN THE  DEVELOPMENT OF DIAGNOSTIC OR THERAPEUTIC  PRODUCTS BASED ON NEW
TECHNOLOGIES.

Product  development  for cancer  treatment  involves a high degree of risk. The
product  candidates  we  develop,  pursue  or offer may not prove to be safe and
effective,  may not receive the necessary regulatory approvals, may be precluded
by  proprietary  rights of third parties or may not  ultimately  achieve  market
acceptance.   These  product  candidates  will  require  substantial  additional
investment,  laboratory  development,  clinical testing and regulatory approvals
prior  to  their  commercialization.  We may  experience  difficulties,  such as
inability to receive timely  regulatory  approvals,  that could delay or prevent
the successful development, introduction and marketing of new products.

Before we obtain  regulatory  approvals  for the  commercial  sale of any of our
products under development,  we must demonstrate through preclinical studies and
clinical  trials that the product is safe and efficacious for use in each target
indication.  The results from preclinical  studies and early clinical trials may
not be predictive of results that will be obtained in large-scale  testing.  Our
clinical trials may not demonstrate  safety and efficacy of a proposed  product,
and therefore,  may not result in marketable  products. A number of companies in
the  biotechnology  industry  have  suffered  significant  setbacks  in advanced
clinical trials, even after promising results in earlier trials. Clinical trials
or marketing of any potential  diagnostic or therapeutic  products may expose us
to liability claims for the use of these diagnostic or therapeutic  products. We
may not be able to maintain product liability  insurance or sufficient  coverage
may not be available at a reasonable cost. In addition, as we develop diagnostic
or therapeutic products internally, we will have to make significant investments
in  diagnostic  or  therapeutic  product  development,   marketing,   sales  and
regulatory compliance resources.  We will also have to establish or contract for
the  manufacture  of  products,  including  supplies  of drugs used in  clinical
trials, under the current Good Manufacturing  Practices, or cGMP, of the FDA. In
addition, the FDA may, among other things,

                                     - 9 -
subsequently   disapprove  or  may  recall  our  product  candidates  that  were
previously  approved.  We also cannot  assure you that  product  issues will not
arise following successful clinical trials and FDA approval.

The rate of  completion  of clinical  trials also depends on the rate of patient
enrollment.  Patient enrollment  depends on many factors,  including the size of
the patient population, the nature of the protocol, the proximity of patients to
clinical  sites and the  eligibility  criteria for the study.  Delays in planned
patient enrollment may result in increased costs and delays,  which could have a
harmful effect on our ability to develop the products in our pipeline. If we are
unable to develop and  commercialize  products on a timely  basis or at all, our
business could be significantly and adversely affected.

COMPETITION IN OUR FIELD IS INTENSE AND LIKELY TO INCREASE.

We face, and will continue to face, intense  competition from one or more of the
following entities:

o     pharmaceutical companies;

o     biotechnology companies;

o     bioinformatics companies;

o     diagnostic companies;

o     academic and research institutions; and

o     government agencies.

All of our products and product candidate are subject to significant competition
from organizations that are pursuing technologies and products that are the same
as or  similar  to our  technology  and  products.  Many  of  the  organizations
competing  with us have greater  capital  resources,  research  and  development
staffs and facilities and marketing capabilities.

The markets for  therapeutic and diagnostic  products that address  prostate and
bladder  cancers are large.  Our most  significant  competitors  include various
pharmaceutical  and medical device companies,  radiopharmaceutical  distributors
and biotechnology companies.

Metastron   (Strontium-89),   which   competes  with   Quadramet   (Samarium-153
Lexidronam),  is manufactured and distributed by Amersham  Health.  Amersham has
announced plans to transfer  marketing  rights for Metastron to Oncura.  The FDA
recently approved a generic version of Sr-89 for bone pain palliation,  which is
marketed by Bio-Nucleonics Pharma as Strontium Chloride Sr-89 Injection, USP.

A single agent,  Positron Emission  Tomography (PET),  competes with ProstaScint
(Capromab pendetide). PET imaging agent, 18-F  fluorodeoxyglucose-PET  (FDG), is
produced  and  distributed  by various  radiopharmaceutical  suppliers  (such as
PETnet and Cardinal  Health Nuclear  Pharmacy  Services).  PET (FDG) may also be
used to image  lymph  node  metastasis  in  cancer  patients,  which  may  prove
competitive  to Combidex,  following FDA approval,  if received,  and subsequent
market introduction of Combidex.

Polymedco  manufactures  BTAstat,  a point of care urine-based test approved for
monitoring bladder cancer patients.  BTAstat,  marketed by Mentor, competes with
NMP22 BladderChek (which we have licensed from Matritech). NMP22 BladderChek is,
however,  the only point of care  urine-based  test approved for both monitoring
and diagnosis of bladder  cancer.  Matritech has retained rights to market

                                     - 10 -
NMP22 BladderChek  directly to physicians other than urologists and oncologists,
such as primary care physicians.

Additionally,  we face competition in the development of PSMA-related technology
and products primarily from Millenium Pharmaceuticals, Inc. and Medarex, Inc.

Before we recover  development  expenses for our products and technologies,  the
products  or  technologies  may  become  obsolete  as a result of  technological
developments  by others or us. Our products  could also be made  obsolete by new
technologies,  which are less expensive or more effective. We may not be able to
make the enhancements to our technology  necessary to compete  successfully with
newly  emerging  technologies  and  failure  to do so  could  significantly  and
adversely affect our business.

WE RELY HEAVILY ON OUR COLLABORATIVE PARTNERS.

Our success depends in significant part upon the success and financial stability
of our collaborative partners. We have entered into the following agreements for
the sale,  marketing,  distribution  and  manufacture  of our products,  product
candidates and technologies:

o     license  from  The  Dow  Chemical   Company   relating  to  the  Quadramet
      technology;

o     agreement for  manufacture of Quadramet by Bristol Myers Squibb  (formerly
      The DuPont Pharmaceuticals Company);

o     joint venture with Progenics  Pharmaceuticals  for the development of PSMA
      for in vivo immunotherapy for prostate and other cancers;

o     licensing  agreement with  Molecular  Staging for technology to be used in
      developing  in vitro  diagnostic  tests using PSMA and  prostate  specific
      antigen, or PSA;

o     a Supply  Agreement  with  Laureate  Pharma  L.P.  for the  production  of
      ProstaScint;

o     an agreement with Matritech to market and distribute NMP22  BladderChek to
      urologists and oncologists in the United States;

o     marketing,  license and supply  agreements with Advanced  Magnetics,  Inc.
      related to Combidex and Code 7228;

o     a License  Agreement between our joint venture,  PSMA Development  Company
      LLC, and AlphaVax Human Vaccines, Inc.; and

o     a Collaboration Agreement between our joint venture and Abgenix, Inc.

Because our collaborative partners are responsible for certain manufacturing and
distribution  activities,  among others, these activities are outside our direct
control and we rely on our partners to perform their  obligations.  For example,
Matritech  retained the ability to market its NMP22  BladderChek to primary care
physicians  and others and has begun such marketing  efforts.  In the event that
our collaborative  partners are entitled to enter into third party  arrangements
that may  economically  disadvantage us, or breach their  obligations  under our
agreements,  our products may not be commercially  successful.  As a result, any
success may be delayed and new product  development  could be inhibited with the
result that our business could be significantly and adversely affected.

                                     - 11 -
OUR  BUSINESS  COULD BE HARMED IF CERTAIN  AGREEMENTS  EXPIRE OR ARE  TERMINATED
EARLY.

If our collaborative  agreements expire or are terminated and we cannot renew or
replace them on  commercially  reasonable  terms,  our  business  and  financial
results may suffer.  For example,  in January 2003, we provided  Draximage  Inc.
with  notice of our intent to  terminate  our Product  Manufacturing  and Supply
Agreement  and License  Agreement  with  Draximage  relating  to the  BrachySeed
products  which  represented  20% of our product  related  revenues for the year
ended  December 31,  2002.  In April 2003,  we entered  into an  agreement  with
Draximage formally terminating each of these agreements. We no longer market and
sell the BrachySeed products.

We  currently  depend on the  following  agreements  for our  present and future
operating results:

      Dow Chemical:

In March 1993, we obtained an exclusive license from The Dow Chemical Company to
North American rights to use Quadramet as a therapeutic  radiopharmaceutical for
metabolic  bone disease or tumor  regression  for cancer caused by metastatic or
primary cancer in bone in humans, and for the treatment of disease characterized
by  osteoblastic  response in humans.  Our license was expanded to include Latin
America in 1995. Our license  agreement with Dow with respect to Quadramet shall
remain in effect, unless earlier terminated pursuant to the terms thereof, for a
term of twenty (20) years from March 31, 1993 or until the last to expire of the
related  patents.  We currently  anticipate such  termination date to be June 9,
2015.

      Bristol-Myers Squibb:

Upon  our   reacquisition   of  marketing   rights  to  Quadramet   from  Berlex
Laboratories,  Inc. in August 2003, we assumed all of Berlex's right, duties and
obligations under that certain  Manufacturing and Supply Agreement dated January
1, 1999 by and among Cytogen,  Berlex and Bristol-Myers  Squibb (formerly DuPont
Pharmaceuticals  Company) for the manufacture of Quadramet. The original term of
this  agreement  was to expire on December  31,  2003.  However,  the  agreement
automatically  renews for successive two-year periods,  unless terminated by BMS
or  Cytogen  on two  years'  written  notice.  The  term of this  agreement  has
therefore been extended through December 31, 2005.

      Matritech:

In October 2002, we entered into a Distribution  Agreement with Matritech,  Inc.
to  be  the  sole  distributor  for  Matritech's  NMP22  BladderChek  device  to
urologists and  oncologists  in the United States.  Our retention of exclusivity
rights depends upon us meeting certain minimum annual  purchases.  Our agreement
with Matritech  shall remain in effect until  December 15, 2007,  unless earlier
terminated in accordance with terms of such agreement.  The agreement shall also
be renewed for  successive  one (1) year  terms,  upon  mutual  written  consent
provided at least ninety (90) days prior to the end of the term of the agreement
(including any renewal thereof).

      Laureate:

In January 2003, we entered into a Contract  Manufacturing  and Supply Agreement
with  Laureate  Pharma  L.P.,   pursuant  to  which  Laureate  is  obligated  to
manufacture  ProstaScint  for us through  December 31,  2003.  We do not plan to
manufacture any ProstaScint in 2004.

                                     - 12 -
Memorial Sloan-Kettering Cancer Center:

In 1993, we began a development  program with  Memorial  Sloan-Kettering  Cancer
Center involving PSMA and our proprietary monoclonal antibody. In November 1996,
we exercised an option for, and obtained, an exclusive worldwide license to this
technology.  The term of the license  shall end on the date of expiration of the
last to expire of the related patents unless it earlier  terminates by operation
of law or by acts of the parties in accordance with the terms of the agreement.

      The University of North Carolina at Chapel Hill:

In March 1993, we entered into a License  Agreement with The University of North
Carolina  at  Chapel  Hill,  pursuant  to  which  UNC  granted  Cytogen  and our
affiliates an exclusive  world-wide license with respect to certain  technology,
patents  and  patent  applications  related to  certain  aspects  of  proteomics
technology,  including our phage display.  The agreement  commenced on March 10,
1993 and will expire,  unless earlier  terminated as provided therein,  upon the
expiration  of the last to expire of the licensed  patents that cover a licensed
product.

      Advanced Magnetics, Inc.:

In August 2000, we entered into a license and marketing  agreement with Advanced
Magnetics,  Inc. for Combidex,  an  investigational  magnetic  resonance imaging
(MRI)  contrast  agent that assists in the  differentiation  of metastatic  from
non-metastatic  lymph nodes. We hold exclusive United States marketing rights to
Combidex. Advanced Magnetics is continuing its discussions with the FDA relating
to outstanding issues regarding an approvable letter received from the FDA dated
June 2000, in an effort to bring  Combidex to market.  Our license and marketing
agreement with Advanced Magnetics will continue until August 25, 2010, and shall
thereafter  automatically renew for successive five year periods,  unless notice
of  non-renewal or  termination  is given by us or Advanced  Magnetics,  90 days
prior to the commencement of any renewal period.

If the licenses and/or agreements described above are terminated,  we may not be
able to find  suitable  alternatives  to them on a timely basis or on reasonable
terms, if at all. The loss of the right to use these  technologies  that we have
licensed or the loss of any services provided to us under these agreements would
significantly and adversely affect our business.

WE HAVE LIMITED SALES, MARKETING AND DISTRIBUTION CAPABILITIES FOR OUR PRODUCTS.

We have  established an internal  sales force that is responsible  for marketing
and selling ProstaScint, Quadramet and NMP22 BladderChek. However, such internal
sales force has limited sales,  marketing and distribution  capabilities for our
products,  compared  to those of many of our  competitors.  Effective  August 1,
2003, we reacquired marketing rights to Quadramet from Berlex Laboratories, Inc.
in North and Latin  America,  for an  upfront  payment of $8.0  million  and the
obligation  to pay  royalties  to Berlex on future  sales of  Quadramet.  If our
internal sales force is unable to successfully  market  Quadramet,  our business
and financial condition may be adversely affected. If we are unable to establish
and maintain  significant sales,  marketing and distribution  efforts within the
United States, either internally or through arrangements with third parties, our
business may be significantly  and adversely  affected.  In locations outside of
the United States, we have not established a selling presence.

THERE ARE RISKS ASSOCIATED WITH THE MANUFACTURE AND SUPPLY OF OUR PRODUCTS.

If we are to be  successful,  our  products  will  have  to be  manufactured  by
contract  manufacturers in compliance with regulatory  requirements and at costs
acceptable to us. If we are unable to  successfully

                                     - 13 -
arrange for the  manufacture  of our  products  and product  candidates,  either
because  potential  manufacturers  are not cGMP compliant,  are not available or
charge excessive amounts, we will not be able to successfully  commercialize our
products and our business will be significantly and adversely affected.

ProstaScint was manufactured at a cGMP compliant manufacturing facility operated
by  Laureate  Pharma  L.P.  (formerly  Bard  BioPharma  L.P.).  We had access to
Laureate's  facility for  continued  manufacturing  of the product until January
2002.  We  entered  into a  Development  and  Manufacturing  Agreement  with DSM
Biologics  Company  B.V.  in July 2000,  which we  intended  would  replace  our
arrangement with Laureate with respect to ProstaScint. Our relationship with DSM
has  subsequently  terminated.  We  entered  into a new  Contract  Manufacturing
Agreement  with Laureate  Pharma L.P. in January 2003. Our failure to maintain a
long term supply agreement on commercially reasonable terms will have a material
adverse effect on our business, financial condition and results of operations.

Quadramet is  manufactured  by  Bristol-Myers  Squibb (BMS)  (formerly  DuPont),
pursuant  to  an  agreement   with  Cytogen.   Some   components  of  Quadramet,
particularly  Samarium153 and EDTMP,  are provided to BMS by outside  suppliers.
Due to radioactive  decay,  Samarium153  must be produced on a weekly basis. BMS
obtains its requirements for Samarium153 from one supplier.  Alternative sources
for  these  components  may  not be  readily  available.  If BMS  cannot  obtain
sufficient quantities of the components on commercially  reasonable terms, or in
a timely  manner,  it would be unable to  manufacture  Quadramet on a timely and
cost-effective  basis,  which  could  have  a  material  adverse  effect  on our
business, financial condition and results of operations.

Pursuant to the terms of our distribution  agreement with Matritech,  we rely on
Matritech as the sole supplier of NMP22 BladderChek.  Matritech uses independent
contractors to manufacture  the product.  If Matritech fails to, or is unable to
provide  the  product,  we could  experience  a material  adverse  effect on our
business, financial condition and results of operations.

The Company, our contract manufacturers and testing laboratories are required to
adhere to United  States Food & Drug  Administration  regulations  setting forth
requirements for cGMP, and similar regulations in other countries, which include
extensive testing,  control and documentation  requirements.  Ongoing compliance
with cGMP,  labeling and other applicable  regulatory  requirements is monitored
through  periodic  inspections  and  market  surveillance  by state and  federal
agencies,  including  the FDA, and by  comparable  agencies in other  countries.
Failure of our  contract  vendors or us to comply  with  applicable  regulations
could result in sanctions  being imposed on us,  including  fines,  injunctions,
civil  penalties,  failure of the  government  to grant  premarket  clearance or
premarket  approval of drugs,  delays,  suspension  or  withdrawal of approvals,
seizures  or  recalls  of   products,   operating   restrictions   and  criminal
prosecutions any of which could significantly and adversely affect our business.

FAILURE OF CONSUMERS TO OBTAIN ADEQUATE  REIMBURSEMENT  FROM THIRD-PARTY  PAYORS
COULD LIMIT MARKET ACCEPTANCE AND AFFECT PRICING OF OUR PRODUCTS.

Our business,  financial condition and results of operations will continue to be
affected by the efforts of governments and other  third-party  payors to contain
or reduce the costs of  healthcare.  There have been,  and we expect  that there
will  continue  to be, a number of  federal  and state  proposals  to  implement
government  control of pricing and  profitability  of therapeutic and diagnostic
imaging  agents such as our products.  In addition,  an emphasis on managed care
increases  possible  pressure  on  pricing  of these  products.  While we cannot
predict whether these  legislative or regulatory  proposals will be adopted,  or
the effects  these  proposals or managed care efforts may have on our  business,
the  announcement  of these  proposals  and the  adoption of these  proposals or
efforts  could affect our stock price or our  business.

                                     - 14 -
Further,  to the extent these  proposals  or efforts  have an adverse  effect on
other  companies that are our  prospective  corporate  partners,  our ability to
establish necessary strategic alliances may be harmed.

Sales of our  products  depend in part on  reimbursement  to the  consumer  from
third-party payors,  including  Medicare,  Medicaid and private health insurance
plans.  Third-party  payors are increasingly  challenging the prices charged for
medical products and services. If third-party payors determine that our products
are  not  cost-effective,  they  may  discontinue  reimbursement  to  consumers.
Alternatively,  such reimbursement may not be sufficient to allow us to sell our
products on a competitive basis. Approval of our products for reimbursement by a
third-party  payor may  depend on a number of  factors,  including  the  payor's
determination  that our  products  are  clinically  useful  and  cost-effective,
medically  necessary and not experimental or  investigational.  Reimbursement is
determined by each payor  individually and in specific cases. The  reimbursement
process  can  be  time  consuming.  If we  cannot  secure  adequate  third-party
reimbursement  for  our  products,  our  business  could  be  significantly  and
adversely affected.

IF WE ARE UNABLE TO COMPLY WITH APPLICABLE GOVERNMENTAL REGULATION WE MAY NOT BE
ABLE TO CONTINUE OUR OPERATIONS.

Any products tested, manufactured or distributed by us or on our behalf pursuant
to FDA approvals are subject to pervasive and continuing  regulation by numerous
regulatory authorities, including primarily the FDA. We may be slow to adapt, or
we may never  adapt to changes  in  existing  requirements  or  adoption  of new
requirements  or policies.  Our failure to comply with  regulatory  requirements
could subject us to enforcement  action,  including product  seizures,  recalls,
withdrawal,   suspension,  or  revocation  of  approvals,   restrictions  on  or
injunctions  against  marketing our products based on our technology,  and civil
and criminal  penalties.  We may incur significant costs to comply with laws and
regulations in the future or compliance  with laws or regulations  may create an
unsustainable burden on our business.

Numerous federal, state and local governmental authorities, principally the FDA,
and similar  regulatory  agencies in other  countries,  regulate the preclinical
testing,  clinical trials,  manufacture and promotion of any compounds or agents
we or our collaborative partners develop, and the manufacturing and marketing of
any resulting drugs. The product  development and regulatory approval process is
lengthy, expensive, uncertain and subject to delays.

The regulatory risks we face also include the following:

o     any  compound  or  agent we or our  collaborative  partners  develop  must
      receive  regulatory agency approval before it may be marketed as a drug in
      a particular country;

o     the regulatory  process,  which includes  preclinical testing and clinical
      trials of each  compound  or agent in order to  establish  its  safety and
      efficacy, varies from country to country, can take many years and requires
      the expenditure of substantial resources;

o     in all  circumstances,  approval  of  the  use  of  previously  unapproved
      radioisotopes in certain of our products  requires  approval of either the
      Nuclear  Regulatory  Commission or equivalent state  regulatory  agencies,
      which may be a lengthy  process.  A radioisotope is an unstable form of an
      element which undergoes  radioactive  decay,  thereby  emitting  radiation
      which may be used,  for example,  to image or destroy  harmful  growths or
      tissue;

o     data obtained from preclinical and clinical  activities are susceptible to
      varying  interpretations  which could delay,  limit or prevent  regulatory
      agency approval; and

                                     - 15 -
o     delays or rejections may be  encountered  based upon changes in regulatory
      agency policy during the period of product  development  and/or the period
      of review of any application for regulatory agency approval.  These delays
      could   adversely   affect  the  marketing  of  any  products  we  or  our
      collaborative   partners  develop,   impose  costly  procedures  upon  our
      activities,  diminish any competitive  advantages we or our  collaborative
      partners may attain and adversely affect our ability to receive royalties.

Regulatory  agency  approval  for a product or agent may not be received and may
entail  limitations on the indicated uses that could limit the potential  market
for any such  product.  For  example,  as  disclosed  in our press  releases and
periodic filings,  we have exclusive United States marketing rights to Combidex,
an ultrasmall superparamagnetic iron oxide contrast agent for magnetic resonance
imaging of lymph nodes,  that is pending clearance by the United States Food and
Drug  Administration.  In June 2000,  Advanced  Magnetics received an approvable
letter from the FDA with respect to Combidex.  An approvable letter is a written
communication  to an applicant from the FDA stating that the agency will approve
the application or abbreviated application if specific additional information or
material is submitted or specific  conditions are met. An approvable letter does
not constitute approval of any part of an application or abbreviated application
and does not permit marketing of the drug that is the subject of the application
or abbreviated  application.  We are awaiting  further  information from the FDA
regarding Combidex.

Furthermore, if and when such approval is obtained, the marketing,  manufacture,
labeling,  packaging,  reporting,  storage, advertising and promotion and record
keeping  related to our products  would remain  subject to extensive  regulatory
requirements.  Discovery  of  previously  unknown  problems  with  a  drug,  its
manufacture  or its  manufacturer  may  result  in  restrictions  on such  drug,
manufacture or manufacturer,  including  withdrawal of the drug from the market.
Failure  to  comply  with  regulatory   requirements   could  result  in  fines,
injunctions,   seizures,   recalls,   suspension  or  withdrawal  of  regulatory
approvals, operating restrictions and criminal prosecution.

The United States Food, Drug and Cosmetics Act requires (i) that our products be
manufactured in FDA registered  facilities subject to inspection,  and (ii) that
we  comply  with  cGMP,  which  imposes  certain  procedural  and  documentation
requirements   upon  us  and  our   manufacturing   partners   with  respect  to
manufacturing and quality assurance  activities.  If we or our contract partners
do not  comply  with  cGMP we may be  subject  to  sanctions,  including  fines,
injunctions,  civil penalties, recalls or seizures of products, total or partial
suspension of production,  product  recalls,  failure of the government to grant
premarket  clearance or premarket  approval for drugs,  withdrawal  of marketing
approvals and criminal prosecution.

WE COULD BE NEGATIVELY  IMPACTED BY FUTURE  INTERPRETATION  OR IMPLEMENTATION OF
FEDERAL  AND STATE  FRAUD AND ABUSE  LAWS,  INCLUDING  ANTI-KICKBACK  LAWS,  THE
FEDERAL STARK LAW AND OTHER FEDERAL AND STATE ANTI-REFERRAL LAWS.

We are subject to various federal and state laws pertaining to health care fraud
and  abuse,  including  anti-kickback  laws and  physician  self-referral  laws.
Violations  of these laws are  punishable  by criminal  and/or civil  sanctions,
including,  in some instances,  imprisonment and exclusion from participation in
federal  and state  health  care  programs,  including  Medicare,  Medicaid  and
Veterans  Administration  health  programs.  We have  not been  challenged  by a
governmental  authority  under any of these laws and believe that our operations
are in compliance with such laws. However, because of the far-reaching nature of
these laws,  we may be required to alter one or more of our  practices  to be in
compliance with these laws.  Health care fraud and abuse regulations are complex
and even minor,  inadvertent  irregularities can potentially give rise to claims
that the statute has been violated. Any violations of these laws could result in
a material  adverse effect on our business,  financial  condition and results of
operations.  If  there is a

                                     - 16 -
change in law, regulation or administrative or judicial interpretations,  we may
have to change our business  practices or our existing business  practices could
be challenged  as unlawful,  which could have a material  adverse  effect on our
business, financial condition and results of operations.

We could become subject to false claims litigation under federal statutes, which
can lead to civil  money  penalties,  criminal  fines and  imprisonment,  and/or
exclusion from  participation in Medicare,  Medicaid and other federal and state
health care programs.  These false claims statutes include the False Claims Act,
which allows any person to bring suit alleging false or fraudulent  claims under
federal  programs or contracts  claims or other violations of the statute and to
share  in any  amounts  paid  by  the  entity  to the  government  in  fines  or
settlement.  Such suits, known as qui tam actions, have increased  significantly
in recent years and have increased the risk that a health care company,  such as
us, will have to defend a false claim action,  pay fines or be excluded from the
Medicare  program,  Medicaid  programs or other  federal  and state  health care
programs as a result of an investigation  arising out of such action.  If we are
unsuccessful  in  defending  against  any such  action,  such  action may have a
material  adverse  effect on our  business,  financial  condition and results of
operations.

WE DEPEND ON ATTRACTING AND RETAINING KEY PERSONNEL.

We are  highly  dependent  on  the  principal  members  of  our  management  and
scientific  staff.  The  loss of their  services  might  significantly  delay or
prevent the  achievement  of development  or strategic  objectives.  Our success
depends  on our  ability  to retain  key  employees  and to  attract  additional
qualified employees.  Competition for personnel is intense, and therefore we may
not be able to retain existing personnel or attract and retain additional highly
qualified employees in the future.

During 2002, we announced  numerous changes to members of our senior management.
H. Joseph Reiser,  Ph.D. who held the position of President and Chief  Executive
Officer of the Company from April 1998 until  December  2002,  resigned from his
position for personal reasons.  Michael D. Becker,  our former Vice President of
Business Development, was unanimously elected by our board of directors to serve
as Dr. Reiser's replacement as President and Chief Executive Officer. Mr. Becker
was also unanimously elected to serve on our Board of Directors.  Dr. Reiser has
remained a member of our Board of Directors.  In addition,  Lawrence R. Hoffman,
our Vice President and Chief Financial Officer since July 2000, left the Company
to pursue  other  opportunities  as of  December  31,  2002.  Ms. Thu Dang,  our
Director of Finance, was subsequently promoted to Vice President of Finance.

Additionally,  in the first  quarter of 2003:  (i) William  Goeckeler,  our Vice
President  of  Research  and   Development   was  promoted  to  Vice  President,
Operations;  (ii) Deborah  Kaminsky,  our Vice President of Sales and Marketing,
shifted her work focus, and serves as our Vice President,  Business Development;
(iii)  Rita  Auld,  our  Director  of  Human  Resources,  was  promoted  to Vice
President,  Human Resources and  Administration  and Corporate  Secretary;  (iv)
Corey Jacklin assumed the  responsibilities of Senior Director of Sales; and (v)
June Gobern was promoted to Senior Director of Marketing.

On September  4, 2003,  Christopher  P.  Schnittker  joined  Cytogen as our Vice
President and Chief Financial Officer.

On December 17, 2002, we entered into a letter  agreement with Michael D. Becker
in  connection  with Mr.  Becker's  promotion to President  and Chief  Executive
Officer of the Company.  Under the terms of such letter  agreement,  Mr.  Becker
receives an annual  base  salary of  $250,000.  Mr.  Becker is also  eligible to
participate  in  our  Cytogen  Corporation  Performance  Bonus  Plan,  as and if
approved  by our Board of  Directors,  with a target  bonus  rate of 30% of base
salary based upon  performance  objectives.  Mr.  Becker is also entitled to all
existing Company benefits, at the sole discretion of the Board of Directors.  In
addition,  Mr.  Becker was  granted  options to purchase  200,000  shares of our
common  stock  under our

                                     - 17 -
1995 Stock Option Plan.  Pursuant to the terms of the letter  agreement,  in the
event we terminate Mr. Becker's  employment for reasons other than for cause, as
defined therein, Mr. Becker shall be entitled to receive twelve month's base pay
and  continuation  of  benefits  under  COBRA,  and a pro  rata  portion  of any
incentive benefits earned through the date of termination.

Each of our  executive  officers is currently  party to an  Executive  Change of
Control Severance Agreement with Cytogen.  Such agreements  provide,  generally,
for the  payment of twelve  months'  base  salary,  a  pro-rata  portion of such
officer's  bonus  compensation,  the  continuation  of all benefits,  reasonable
Company-paid  outplacement  assistance and certain other accrued rights,  in the
event such officer's employment with us is terminated in connection with certain
changes in control.

We do not carry key person life insurance policies and we do not typically enter
into long-term arrangements with our key personnel. If we are unable to hire and
retain  personnel in key  positions,  our business  could be  significantly  and
adversely affected unless qualified replacements can be found.

OUR  BUSINESS  EXPOSES  US TO  POTENTIAL  LIABILITY  CLAIMS  THAT MAY EXCEED OUR
FINANCIAL  RESOURCES,  INCLUDING  OUR  INSURANCE  COVERAGE,  AND MAY LEAD TO THE
CURTAILMENT OR TERMINATION OF OUR OPERATIONS.

Our  business is subject to product  liability  risks  inherent in the  testing,
manufacturing  and marketing of our products and product liability claims may be
asserted  against us, our  collaborators  or our  licensees.  While we currently
maintain  product  liability  insurance  in the  amount of $10.0  million,  such
coverage  may not be adequate  to protect us against  future  product  liability
claims. In addition,  product liability  insurance may not be available to us in
the future on commercially reasonable terms, if at all. Although we have not had
a history of claims  payments  that have  exceeded  our  insurance  coverage  or
available  financial  resources,  if  liability  claims  against  us exceed  our
financial resources or coverage amounts, we may have to curtail or terminate our
operations.  In addition,  while we currently  maintain  directors  and officers
liability  insurance in the amount of $20.0  million,  such  coverage may not be
available on  commercially  reasonable  terms or be adequate to cover any claims
that we may be  required  to satisfy in the future.  Our  insurance  coverage is
subject to industry standard and certain other limitations.

OUR BUSINESS INVOLVES ENVIRONMENTAL RISKS THAT MAY RESULT IN LIABILITY.

We are subject to a variety of local,  state,  federal  and  foreign  government
regulations  relating to storage,  discharge,  handling,  emission,  generation,
manufacture and disposal of toxic, infectious or other hazardous substances used
to manufacture  our products.  If we fail to comply with these  regulations,  we
could be liable  for  damages,  penalties,  or other  forms of  censure  and our
business  could be  significantly  and adversely  affected.  We currently do not
carry  insurance  for  contamination  or injury  resulting  from the use of such
materials.

Two of our marketed  products,  ProstaScint  and Quadramet  utilize  radioactive
materials.  ProstaScint is not manufactured or shipped as a radioactive material
because the radioactive  component is not added until the product has arrived at
its  final  destination  (a   radiopharmacy).   Laureate  Pharma,  the  contract
manufacturer of ProstaScint,  holds a radioactive materials license because such
license is required for certain release and stability tests of the product.

Quadramet,  however, is manufactured and shipped as radioactive,  and therefore,
the  manufacturing and distribution of this product must comply with regulations
promulgated  by the U.S.  Nuclear  Regulatory  Commission.  Bristol Myers Squibb
manufacturers and distributes  Quadramet,  and is,  therefore,  subject to these
regulations.

                                     - 18 -
OUR INTELLECTUAL PROPERTY IS DIFFICULT TO PROTECT.

Our business and competitive positions are dependent upon our ability to protect
our  proprietary  technology.  Because  of the  substantial  length  of time and
expense  associated with  development of new products,  we, like the rest of the
biopharmaceutical  industry,  place  considerable  importance  on obtaining  and
maintaining  patent and trade secret protection for new  technologies,  products
and  processes.  We  have  filed  patent  applications  for our  technology  for
diagnostic  and  therapeutic  products and the methods for their  production and
use.

In  addition,  the  protection  afforded by a duly  issued  patent is limited in
duration.  With respect to our ProstaScint  product, we rely primarily on United
States patent numbers 5,763,202  (expiring June 9, 2015) and 5,162,504 (expiring
October 28, 2010).  Such patents were assigned to us by Julius S.  Horosziewicz.
With respect to Quadramet,  we rely  primarily on United  States patent  numbers
5,066,478  (expiring  November 19, 2008),  5,300,279  (expiring  April 5, 2011),
5,762,907  (expiring  June 19,  2015),  5,714,604  (expiring  February 3, 2015),
4,897,254  (expiring January 30, 2007) and 4,898,724  (expiring March 28, 2011),
which were licensed to us by The Dow Chemical Company.  In addition,  we rely on
United States patent number  5,495,042  (expiring  November 4, 2013),  which was
assigned to us by Benjamin A. Belinka, Jr.

The patent  positions of  pharmaceutical,  biopharmaceutical  and  biotechnology
companies,  including us, are generally  uncertain and involve complex legal and
factual questions.  Our patent applications may not protect our technologies and
products because, among other things:

o     there is no guarantee  that any of our pending  patent  applications  will
      result in issued patents;

o     we  may  develop   additional   proprietary   technologies  that  are  not
      patentable;

o     there is no guarantee that any patents issued to us, our  collaborators or
      our licensors will provide a basis for a commercially viable product;

o     there is no guarantee that any patents  issued to us or our  collaborators
      will provide us with any competitive advantage;

o     there is no guarantee that any patents  issued to us or our  collaborators
      will not be challenged, circumvented or invalidated by third parties; and

o     there is no  guarantee  that any  patents  previously  issued to others or
      issued in the future will not have an adverse  effect on our ability to do
      business.

In  addition,  patent  law in the  technology  fields  in  which we  operate  is
uncertain and still evolving.  The degree of protection that may be afforded any
patents we are issued or license  from others may not be  sufficient  to protect
our commercial interests.  Furthermore, others may independently develop similar
or  alternative  technologies,  duplicate our  technologies,  or, if patents are
issued to us, design around the patented technologies  developed by us. We could
incur  substantial costs in litigation if we are required to defend ourselves in
patent suits by third  parties or if we initiate  such suits.  In  addition,  if
challenged by others in litigation, the patents we have been issued, or which we
have been assigned or we have licensed from others may be found  invalid.  It is
also possible that our activities may infringe patents owned by others.  Defense
and  prosecution  of patent  matters can be expensive  and  time-consuming  and,
regardless  of  whether  the  outcome  is  favorable  to us,  can  result in the
diversion of substantial financial,  managerial and other resources.  An adverse
outcome could:

                                     - 19 -
o     subject us to significant liability to third parties;

o     require us to cease any related  research and  development  activities and
      product sales; or

o     require us to obtain licenses from third parties.

Any licenses required under any such third-party  patents or proprietary  rights
may not be available on commercially  reasonable terms, if at all. Moreover, the
laws of certain  countries  may not protect our  proprietary  rights to the same
extent as the laws of the United States.  We cannot  predict  whether our or our
competitors'  pending patent  applications  will result in the issuance of valid
patents which may significantly and adversely affect our business.

OUR SECURITY MEASURES MAY NOT PROTECT OUR UNPATENTED PROPRIETARY TECHNOLOGY.

We also rely upon  trade  secret  protection  for some of our  confidential  and
proprietary  information that is not subject matter for which patent  protection
is available. To help protect our rights, we require all employees, consultants,
advisors and collaborators to enter into confidentiality agreements that require
disclosure,  and in most cases, assignment to us, of their ideas,  developments,
discoveries  and  inventions,  and that prohibit the disclosure of  confidential
information  to anyone  outside  Cytogen or our  subsidiaries.  Although  we are
unaware of any  unauthorized  use or  disclosure of our  unpatented  proprietary
technology to date, these agreements may not provide adequate protection for our
trade  secrets,  know-how  or other  proprietary  information  or  prevent  such
unauthorized use or disclosure.

WE ARE CURRENTLY SUBJECT TO PATENT LITIGATION.

On March 17,  2000,  we were  served with a  complaint  filed  against us in the
United  States  District  Court  for the  District  of New  Jersey  by M.  David
Goldenberg  ("Goldenberg") and Immunomedics,  Inc. (collectively  "Plaintiffs").
The  litigation   claims  that  our  ProstaScint   product  infringes  a  patent
purportedly  owned by Goldenberg and licensed to  Immunomedics.  We believe that
ProstaScint  does not infringe  this patent,  and that the patent is invalid and
unenforceable.  The  patent  sought to be  enforced  in the  litigation  has now
expired;  as a result,  the claim,  even if  successful,  would not result in an
injunction  barring the continued sale of ProstaScint or affect any other of our
products or technology.  In addition,  we have certain rights to indemnification
against litigation and litigation  expenses from the inventor of technology used
in  ProstaScint,  which  may be  offset  against  royalty  payments  on sales of
ProstaScint.  However, given the uncertainty associated with litigation,  we may
incur material  expenditures.  On December 17, 2001,  Cytogen filed a motion for
summary   judgment  of   non-infringement   of  the   asserted   claims  of  the
patent-in-suit.   The  Plaintiffs  opposed  that  motion  and  filed  their  own
cross-motion for summary  judgment of  infringement.  On July 3, 2002, the Court
denied both parties' summary judgment motions, with leave to renew those motions
after presenting  expert testimony and legal argument based upon that testimony.
The parties  subsequently  presented expert  testimony and submitted  additional
briefing. On April 29, 2003, our motion for summary judgment of non-infringement
of all asserted claims was granted,  plaintiffs'  motion for summary judgment of
infringement  was  denied  and the case was  ordered  closed.  On May 12,  2003,
Plaintiffs filed a Notice of Appeal regarding this decision to the U.S. Court of
Appeals for the Federal Circuit,  and subsequently  filed their opening brief in
the Court of Appeals for the Federal  Circuit on July 28, 2003. On September 22,
2003,  Cytogen filed its responsive  brief. The Court has not yet set a date for
the argument on this appeal.

                                     - 20 -
OUR STOCK PRICE HAS BEEN AND MAY CONTINUE TO BE VOLATILE, AND YOUR INVESTMENT IN
OUR STOCK COULD DECLINE IN VALUE OR FLUCTUATE SIGNIFICANTLY.

The market prices for securities of biotechnology and  pharmaceutical  companies
have  historically  been highly  volatile,  and the market has from time to time
experienced  significant price and volume fluctuations that are unrelated to the
operating  performance of particular  companies.  The market price of our common
stock has fluctuated over a wide range and may continue to fluctuate for various
reasons, including, but not limited to, announcements concerning our competitors
or us regarding:

o     results of clinical trials;

o     technological innovations or new commercial products;

o     changes  in  governmental  regulation  or the  status  of  our  regulatory
      approvals or applications;

o     changes in earnings;

o     changes in health care policies and practices;

o     developments or disputes concerning proprietary rights;

o     litigation or public  concern as to safety of the our potential  products;
      and

o     changes in general market conditions.

These  fluctuations may be exaggerated if the trading volume of our common stock
is low. These  fluctuations  may or may not be based upon any of our business or
operating results. Our common stock may experience similar or even more dramatic
price and volume fluctuations which may continue indefinitely.

The following table sets forth the high and low sale prices for our common stock
for each of the quarters in the period beginning July 1, 2000 through  September
30, 2003 as  reported on the Nasdaq  National  Market,  and as adjusted  for our
one-for-ten reverse stock split effected October 25, 2002:

    Quarter Ended               High                    Low
    -------------               ----                    ---

 September 30, 2000            $113.75                  $55.00
 December 31, 2000              $71.88                  $20.00
 March 31, 2001                 $65.63                  $23.13
 June 30, 2001                  $61.00                  $21.88
 September 30, 2001             $53.90                  $19.00
 December 31, 2001              $45.50                  $20.50
 March 31, 2002                 $34.70                  $21.10
 June 30, 2002                  $22.40                   $9.10
 September 30, 2002             $11.50                  $3.20
 December 31, 2002              $8.44                   $2.68
 March 31, 2003                 $3.90                   $2.51
 June 30, 2003                  $8.60                   $2.80
 September 30, 2003             $14.78                  $8.40

                                     - 21 -
WE HAVE ADOPTED VARIOUS  ANTI-TAKEOVER  PROVISIONS WHICH MAY AFFECT THE MARKET
PRICE  OF  OUR  COMMON  STOCK  AND  PREVENT  OR  FRUSTRATE   ATTEMPTS  BY  OUR
STOCKHOLDERS TO REPLACE OR REMOVE OUR MANAGEMENT TEAM.

Our Board of Directors has the authority,  without further action by the holders
of common stock, to issue from time to time, up to 5,400,000 shares of preferred
stock in one or more classes or series, and to fix the rights and preferences of
the  preferred  stock.  Pursuant  to these  provisions,  we have  implemented  a
stockholder  rights plan by which one preferred stock purchase right is attached
to each share of common stock, as a means to deter coercive takeover tactics and
to prevent an acquirer  from  gaining  control of us without  some  mechanism to
secure a fair price for all of our stockholders if an acquisition was completed.
These  rights  will be  exercisable  if a person  or group  acquires  beneficial
ownership  of 20% or more of our  common  stock and can be made  exercisable  by
action of our board of directors  if a person or group  commences a tender offer
which would  result in such person or group  beneficially  owning 20% or more of
our common stock.  Each right will entitle the holder to buy one  one-thousandth
of a share of a new series of our junior participating  preferred stock for $20.
If any person or group becomes the beneficial owner of 20% or more of our common
stock (with certain  limited  exceptions),  then each right not owned by the 20%
stockholder  will  entitle its holder to  purchase,  at the right's then current
exercise price, common shares having a market value of twice the exercise price.
In addition,  if after any person has become a 20% stockholder,  we are involved
in a merger or other business combination  transaction with another person, each
right will entitle its holder (other than the 20%  stockholder) to purchase,  at
the right's then current exercise price,  common shares of the acquiring company
having a value of twice the right's then current exercise price.

We are subject to provisions of Delaware corporate law which, subject to certain
exceptions,  will prohibit us from engaging in any "business combination" with a
person who,  together with  affiliates and  associates,  owns 15% or more of our
common stock for a period of three years following the date that the person came
to own 15% or more of our  common  stock  unless  the  business  combination  is
approved in a prescribed manner.

These   provisions  of  the   stockholder   rights  plan,  our   certificate  of
incorporation, and of Delaware law may have the effect of delaying, deterring or
preventing a change in control of Cytogen,  may  discourage  bids for our common
stock at a premium over market price and may adversely  affect the market price,
and the  voting  and other  rights  of the  holders,  of our  common  stock.  In
addition,  these  provisions  make it more  difficult  to  replace or remove our
current  management team in the event our stockholders  believe this would be in
the best interest of the Company and our stockholders.

THE LIQUIDITY OF OUR COMMON STOCK COULD BE ADVERSELY AFFECTED IF WE ARE DELISTED
FROM THE NASDAQ NATIONAL MARKET.

On August 14, 2002,  we announced  that we had  received  notification  from the
Nasdaq  Stock  Market,  Inc.  that our common stock had closed below the minimum
$1.00 per share  requirement  for the  previous 30  consecutive  trading days as
required under Marketplace Rule 4450(a)(5).  In accordance with Marketplace Rule
4450 (e)(2), we were provided with 90 calendar days, or until November 12, 2002,
to regain compliance by having the bid price for our common stock close at $1.00
or greater for a minimum period of 10 consecutive trading days.

On September  26, 2002,  we  announced  that our Board of Directors  unanimously
approved,  and recommended to our  stockholders,  a proposal that would give the
Board of  Directors  authority  to effect a reverse  stock  split of our  common
stock, at a ratio of up to one-for-ten at any time prior to December 31, 2002. A
special  meeting of our  stockholders  was held on October  25, 2002 to consider
such recommendation. Pursuant to the authority granted to our Board of Directors
at the special  meeting,  on

                                     - 22 -
October 25, 2002, we implemented a one-for-ten  reverse split of our outstanding
and authorized shares of common stock.

We subsequently achieved compliance with Nasdaq Marketplace Rule 4450(a)(5), and
received a letter from Nasdaq  notifying us of such  compliance  on November 11,
2002.

If we do not continue to maintain  compliance with this Marketplace Rule, or any
other Listing  Standards which may apply to us, we may once again face delisting
from the Nasdaq National Market in the future.

In the event that we are unable  maintain  compliance  with all relevant  Nasdaq
Listing  Standards,  our  securities may be subject to delisting from the Nasdaq
National Market. If such delisting occurs, the market price and market liquidity
of our common stock may be adversely affected.

Alternatively,  if faced with such  delisting,  we may submit an  application to
transfer  the listing of our common  stock to the Nasdaq  SmallCap  Market.  The
Nasdaq SmallCap Market also has a $1.00 minimum bid price requirement.

If our common stock is delisted by Nasdaq, our common stock would be eligible to
trade on the OTC Bulletin Board maintained by Nasdaq,  another  over-the-counter
quotation  system,  or on the pink  sheets  where an  investor  may find it more
difficult to dispose of or obtain accurate  quotations as to the market value of
our common stock. In addition,  we would be subject to a rule promulgated by the
Securities and Exchange  Commission  that, if we fail to meet criteria set forth
in such rule,  imposes various practice  requirements on broker-dealers who sell
securities governed by the rule to persons other than established  customers and
accredited  investors.  Consequently,  such rule may deter  broker-dealers  from
recommending or selling our common stock, which may further affect the liquidity
of our common stock.

Delisting  from Nasdaq will make  trading our common  stock more  difficult  for
investors,  potentially leading to further declines in our share price. It would
also make it more difficult for us to raise additional  capital.  Further, if we
are delisted we would also incur  additional  costs under state blue sky laws in
connection with any sales of our securities.  These  requirements could severely
limit  the  market  liquidity  of  our  common  stock  and  the  ability  of our
shareholders to sell our common stock in the secondary market.

A LARGE NUMBER OF OUR SHARES ARE  ELIGIBLE  FOR FUTURE SALE WHICH MAY  ADVERSELY
IMPACT THE MARKET PRICE OF OUR COMMON STOCK.

A large number of shares of our common stock are already  outstanding,  issuable
upon exercise of options and warrants,  or the achievement of certain milestones
under previously  completed  acquisitions and may be eligible for resale,  which
may adversely  affect the market price of our common  stock.  As of September 8,
2003 we had  10,992,382  shares of common  stock  outstanding,  which  number of
shares:  (i) includes an aggregate of 241 shares of common stock to be issued to
prior holders of securities of CytoRad Incorporated and Cellcor,  Inc., which we
acquired in 1995, upon each such holders respective exchange of such securities;
(ii)  excludes  50,000  shares  of  common  stock  previously  issued  by us and
currently held in escrow pending release,  upon certain conditions,  to Advanced
Magnetics, who currently maintains voting control of such securities;  and (iii)
excludes 27,527 shares  previously  issued by us and currently held for issuance
by the  custodian  of our  Employee  Stock  Purchase  Plan  to the  participants
thereunder,  in the event they elect to  purchase  such  shares.  An  additional
414,018  shares of common  stock are issuable  upon the exercise of  outstanding
stock  options and an additional  1,944,485  shares of common stock are issuable
upon the exercise of outstanding warrants,  including the warrants issued to the
selling  stockholders  in this  prospectus.  Substantially  all of  such  shares
subject to  outstanding  options and warrants  will,  when issued upon  exercise
thereof,  be available  for immediate  resale in the public  market

                                     - 23 -
pursuant  to  either a  currently  effective  registration  statement  under the
Securities  Act of  1933,  as  amended,  or  pursuant  to Rule  144 or Rule  701
promulgated  thereunder.  In addition,  there are 148,397  additional  shares of
common stock reserved for future issuance under our current stock options plans,
3,630  additional  shares of common stock reserved for issuance under our 401(k)
Plan and  22,751  additional  shares of common  stock  reserved  for the  future
issuance  under our  employee  bonus plan.  All such  reserved  shares have been
registered  with the  Securities and Exchange  Commission  pursuant to currently
effective  registration  statements.  In addition,  there are 85,480  additional
shares of common  stock,  subject to certain  adjustments,  reserved  for future
issuance in  connection  with the  issuance of a  convertible  promissory  note,
having a seven (7) year maturity, to ELAN Corporation, plc in August 1998.

In connection  with our  acquisition of Prostagen,  Inc. in June 1999, we issued
205,000  unregistered  shares of our common  stock to the then  stockholders  of
Prostagen, which shares may be sold from time to time pursuant to Rule 144 under
the Securities Act. Such stockholders  also have certain piggyback  registration
rights with  respect to these  shares of common  stock.  An  additional  127,699
shares  have  been  issued  in  2002  and  were  subsequently  registered  on  a
registration  statement on Form S-3. An additional $2.0 million worth of Cytogen
common stock,  which we are obligated to register  under the  Securities  Act of
1933, as amended,  may be issued if certain  milestones are achieved in the PSMA
development programs.

On October 25, 2001,  we filed with the  Securities  and  Exchange  Commission a
shelf registration statement on Form S-3 covering 1,000,000 shares of our common
stock. 297,066 and 416,670 of such registered shares were issued to the State of
Wisconsin  Investment Board in private offering  transactions in each of January
2002 and June 2002, respectively.

On July 3, 2003,  we filed  with the SEC a  Registration  Statement  on Form S-3
covering 1,368,422 shares of our common stock, 315,790 of which shares of common
stock are  underlying  warrants.  Such shares of common stock and warrants  were
issued in a private offering  transaction.  Such  Registration  Statement became
effective on September 23, 2003.

On October 1, 2003, we filed with the SEC a  Registration  Statement on Form S-3
covering  2,694,664  shares of our common  stock,  1,522,332  of which shares of
common stock are underlying  warrants.  2,344,664 of such shares of common stock
and warrants were issued in a private offering  transaction,  100,000 additional
warrants  were issued to a  consultant  in  connection  with the  financing  and
250,000  additional  warrants were issued in consideration for certain entities'
waiver  of  certain  rights  with  respect  to the  July  2003  financing.  Such
Registration Statement became effective on October 6, 2003.

Availability  of a significant  number of additional  shares of our common stock
for future sale and issuance could depress the price of our common stock.

BECAUSE WE DO NOT INTEND TO PAY,  AND HAVE NOT PAID,  ANY CASH  DIVIDENDS ON OUR
SHARES OF COMMON STOCK, OUR STOCKHOLDERS WILL NOT BE ABLE TO RECEIVE A RETURN ON
THEIR SHARES UNLESS THE VALUE OF OUR SHARES APPRECIATES AND THEY SELL THEM.

We have never paid or declared  any cash  dividends on our common stock or other
securities and intend to retain any future  earnings to finance the  development
and expansion of our business. We do not anticipate paying any cash dividends on
our common stock in the foreseeable future. Therefore, our stockholders will not
be able to  receive  a return on their  shares  unless  the value of our  shares
appreciates and they sell them.

                                     - 24 -
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

      This prospectus includes or incorporates forward-looking statements within
the meaning of Section 27A of the  Securities Act of 1933 and Section 21E of the
Securities  Exchange  Act of  1934,  as  amended.  All  statements,  other  than
statements of historical  facts,  included or  incorporated  in this  prospectus
regarding our strategy, future operations,  financial position, future revenues,
projected   costs,   prospects,   plans  and   objectives  of   management   are
forward-looking  statements.  The words "anticipates,"  "believes," "estimates,"
"expects,"  "intends," "may," "plans,"  "projects,"  "will," "would" and similar
expressions are intended to identify  forward-looking  statements,  although not
all  forward-looking  statements  contain  these  identifying  words.  We cannot
guarantee  that we actually will achieve the plans,  intentions or  expectations
disclosed  in our  forward-looking  statements  and you should  not place  undue
reliance  on our  forward-looking  statements.  Actual  results or events  could
differ materially from the plans,  intentions and expectations  disclosed in the
forward-looking  statements we make. We have included  important  factors in the
cautionary statements included or incorporated in this prospectus,  particularly
under the heading "Risk Factors",  that we believe could cause actual results or
events to differ  materially from the  forward-looking  statements that we make.
Our forward-looking statements do not reflect the potential impact of any future
acquisitions,  mergers, dispositions, joint ventures or investments we may make.
We do not assume any obligation to update any  forward-looking  statements.  You
should not unduly rely on forward-looking  statements  contained or incorporated
by  reference  in  this  prospectus.  Actual  results  or  outcomes  may  differ
materially  from those  predicted in our  forward-looking  statements due to the
risks and uncertainties inherent in our business.

      You should read and interpret any forward-looking statements together with
the following documents:

o     our most recent Annual Report on Form 10-K, as amended;

o     our most recent quarterly report of Form 10-Q;

o     the risk factors  contained  in this  prospectus  under the caption  "Risk
      Factors"; and

o     our other filings with the Securities and Exchange Commission.

      Any  forward-looking  statement  speaks  only as of the date on which that
statement is made. We will not update any  forward-looking  statement to reflect
events or  circumstances  that occur after the date on which such  statement  is
made.

                                 USE OF PROCEEDS

      Cytogen will not receive any proceeds from the sale of the Shares  covered
by this Prospectus. While Cytogen will receive sums upon any exercise of options
by  the  Selling   Shareholder,   Cytogen  currently  has  no  plans  for  their
application,  other than for general corporate  purposes.  Cytogen cannot assure
you that any of such options will be exercised.

                                     - 25 -
THE SELLING SHAREHOLDER

      The  individual  listed  below  (the  "Selling  Shareholder")  has or will
acquire  the  Shares  being  registered  pursuant  to the  exercise  of  options
previously  granted to him by Cytogen.  The Shares may not be sold or  otherwise
transferred by the Selling  Shareholder  unless and until the applicable options
are exercised in accordance with their terms.

      The following table sets forth:  (i) the name of the Selling  Shareholder;
(ii) his position(s), office or other material relationship with Cytogen and its
predecessors  or  affiliates,  over the last  three  years;  (iii) the number of
shares of Common Stock owned (or subject to options or  convertible  securities)
by such Selling  Shareholder as of the date of this Prospectus and prior to this
offering; (iv) the number of shares of Common Stock which may be offered and are
being registered for the account of such Selling  Shareholder by this Prospectus
(all of which have been or may be acquired by the Selling  Shareholder  pursuant
to the exercise of options subject to the appropriate  vesting of such options);
and (v) the amount of Common  Stock to be owned by such Selling  Shareholder  if
such Selling  Shareholder  was to sell all of his shares of Common Stock covered
by this Prospectus.

      Cytogen cannot assure you that the Selling Shareholder will offer for sale
or sell any or all of the Shares offered by him pursuant to this Prospectus.

                              Number of Shares               Number of Shares /
                              / Percentage of                   Percentage of
                                Common Stock     Number of   Common Stock Owned
                             Prior to Offering   Shares of   After the Offering
                  Position       (both held        Common        (both held
                    with        directly and    Stock to be      directly or
      Name         Cytogen    indirectly) (1)     Offered      indirectly) (2)
--------------    --------   -----------------  -----------  -------------------

Kevin G. Lokay    Director     4,333 / * (3)       1,000          3,333 / *

-----

*     Less than one-percent.

(1)   Applicable percentage of ownership is based on 11,069,668 shares of Common
      Stock   outstanding  as  of  October  20,  2003,  plus  any  Common  Stock
      equivalents or convertible  securities held and shares  beneficially owned
      by such holder as set forth herein.

(2)   Assumes  that all  Shares  to be  offered,  as set forth  above,  are sold
      pursuant to this  offering  and that no other  shares of Common  Stock are
      acquired  or  disposed  of  by  the  Selling   Shareholder  prior  to  the
      termination of this  offering.  Because the Selling  Shareholder  may sell
      all,  some or none of his Shares or may acquire or dispose of other shares
      of Common Stock, no reliable  estimate can be made of the aggregate number
      of Shares  that will be sold  pursuant  to this  offering or the number or
      percentage  of shares of Common Stock that such Selling  Shareholder  will
      own upon completion of this offering.

(3)   Includes  3,333 vested and unvested  options to purchase  shares of Common
      Stock prior to this Offering.

                                     - 26 -
PLAN OF DISTRIBUTION

      The Selling  Shareholder  has not advised Cytogen of any specific plan for
the sale or distribution of the Shares.  If and when they occur,  such sales may
be made in any of the following manners:

      o     On the Nasdaq  National  Market (or  through the  facilities  of any
            national securities exchange or U.S.  inter-dealer  quotation system
            of a registered national securities association, on which the shares
            are then listed, admitted to unlisted trading privileges or included
            for quotation);

      o     In public or privately negotiated transactions;

      o     In transactions involving principals or brokers;

      o     In a combination of such methods of sale; or

      o     Any other lawful methods.

      Although  sales of the Shares  are,  in  general,  expected  to be made at
market  prices  prevailing  at the time of sale,  the Shares may also be sold at
prices related to such prevailing market prices or at negotiated  prices,  which
may differ considerably.

      When  offering  the  Shares  covered  by  this  Prospectus,  such  Selling
Shareholder  and  any  broker-dealers  who  sell  the  Shares  for  the  Selling
Shareholder may be "underwriters"  within the meaning of the Securities Act, and
any profits  realized by such Selling  Shareholders and the compensation of such
broker-dealers may be underwriting discounts and commissions.

      Sales through  brokers may be made by any method of trading  authorized by
any stock exchange or market on which the Shares may be listed,  including block
trading in negotiated transactions. Without limiting the foregoing, such brokers
may act as  dealers  by  purchasing  any or all of the  Shares  covered  by this
Prospectus, either as agents for others or as principals for their own accounts,
and reselling such Shares pursuant to this Prospectus.  The Selling  Shareholder
may effect such  transactions  directly,  or  indirectly  through  underwriters,
broker-dealers  or agents acting on their behalf. In connection with such sales,
such  broker-dealers  or  agents  may  receive   compensation  in  the  form  of
commissions,  concessions, allowances or discounts, any or all of which might be
in excess of customary amounts.

      Such  Selling  Shareholder  is acting  independently  of Cytogen in making
decisions  with  respect to the timing,  manner and size of each sale of Shares.
Cytogen has not been advised of any definitive  selling  arrangement at the date
of this Prospectus  between such Selling  Shareholder and any  broker-dealer  or
agent.

      To the  extent  required,  the  names  of any  agents,  broker-dealers  or
underwriters and applicable commissions,  concessions,  allowances or discounts,
and any other required  information  with respect to any particular offer of the
Shares by the Selling Shareholder, will be set forth in a Prospectus Supplement.

      The  expenses  of  preparing  and filing this  Prospectus  and the related
Registration  Statement with the Securities and Exchange Commission will be paid
entirely by Cytogen.  Shares of Common Stock covered by this Prospectus also may
qualify to be sold pursuant to Rule 144 under the  Securities  Act,  rather than
pursuant to this Prospectus. The Selling Shareholder has been advised that he is
subject to the applicable  provisions of the Securities Exchange Act of 1934, as
amended, including without limitation, Rule 10b-5 thereunder.

                                     - 27 -
Neither  Cytogen nor the Selling  Shareholder  can estimate at the present
time the amount of  commissions  or discounts,  if any, that will be paid by the
Selling Shareholder on account of his sales of the Shares from time to time.

                                  LEGAL MATTERS

      The validity of the shares of Common Stock  offered  hereby will be passed
upon for Cytogen by Hale and Dorr LLP,  650 College  Road East,  Princeton,  New
Jersey 08540.

                                     EXPERTS

      The  consolidated   financial   statements  of  Cytogen   Corporation  and
subsidiaries  as of December  31,  2002 and for the year then  ended,  have been
incorporated by reference herein and in the  registration  statement in reliance
upon   the    reports    of   KPMG    LLP,    independent    accountants,    and
PricewaterhouseCoopers  LLP,  independent  auditors,  incorporated  by reference
herein,  and upon the  authority  of said  firms as experts  in  accounting  and
auditing. The audit report covering the December 31, 2002 consolidated financial
statements  refers to KPMG LLP's audit of the  adjustments  that were applied to
restate  the 2001 and 2000  consolidated  financial  statements,  as more  fully
described in Note 1 to the consolidated financial statements.  However, KPMG LLP
was not engaged to and did not audit,  review,  or apply any  procedures  to the
2001 and 2000 consolidated  financial statements other than with respect to such
adjustments.

      The consolidated  balance sheet of Cytogen  Corporation as of December 31,
2001 and the  consolidated  statements of operations,  stockholders'  equity and
cash flows for each of the years in the two-year period ended December 31, 2001,
have been incorporated by reference in this prospectus,  and in the registration
statement of which this  prospectus  is a part,  from the Annual  Report on Form
10-K of  Cytogen  Corporation.  The  financial  statements  for the years  ended
December 31, 2001 and  December  31, 2000 have been  audited by Arthur  Andersen
LLP,  independent public accountants,  as indicated in their report with respect
thereto,  and are incorporated by reference herein. The Company has not received
an updated or  reissued  copy of such  report  dated  February  5, 2002,  and is
relying solely upon the manually-signed report of Arthur Andersen LLP previously
provided to the Company in connection  with the Company's  Annual Report on Form
10-K for the year ended December 31, 2001. Arthur Andersen LLP has not consented
to the inclusion of their report in this prospectus,  and we have dispensed with
the requirement to file their consent in reliance on Rule 437a promulgated under
the  Securities  Act of  1933,  as  amended.  Because  Arthur  Andersen  has not
consented to the inclusion of their report in this  prospectus,  you will not be
able to recover  against Arthur  Andersen under Section 11 of the Securities Act
of 1933, as amended,  for any untrue  statements of a material fact contained in
the financial  statements audited by Arthur Andersen or any omissions to state a
material fact required to be stated therein.

                       WHERE YOU CAN FIND MORE INFORMATION

      We file reports,  proxy  statements and other  documents with the SEC. You
may read and copy any  document we file at the SEC's  public  reference  room at
Judiciary Plaza Building,  450 Fifth Street, N.W., Room 1024,  Washington,  D.C.
20549.  You  should  call  1-800-SEC-0330  for more  information  on the  public
reference  room. Our SEC filings are also available to you on the SEC's Internet
site at http://www.sec.gov.

      This prospectus is part of a registration statement that we filed with the
SEC. The registration  statement  contains more information than this prospectus
regarding us and our common stock, including certain exhibits and schedules. You
can  obtain a copy of the  registration  statement  from the SEC at the  address
listed above or from the SEC's Internet site.

                                     - 28 -
INFORMATION INCORPORATED BY REFERENCE

      The SEC requires us to "incorporate" into this prospectus information that
we file  with  the SEC in  other  documents.  This  means  that we can  disclose
important  information to you by referring to other  documents that contain that
information.  The information incorporated by reference is considered to be part
of this  prospectus.  Information  contained in this  prospectus and information
that we file with the SEC in the future and  incorporate  by  reference  in this
prospectus automatically updates and supersedes previously filed information. We
incorporate  by reference the documents  listed below and any future  filings we
make with the SEC under  Sections  13(a),  13(c),  14 or 15(d) of the Securities
Exchange  Act of  1934,  prior  to the sale of all the  shares  covered  by this
prospectus.

      1.    Our Annual Report on Form 10-K for the year ended December 31, 2002,
            as filed with the  Securities  and Exchange  Commission on March 31,
            2003 (File No. 000-14879);

      2.    Amendment  No. 1 to our  Annual  Report on Form  10-K/A for the year
            ended  December 31, 2002, as filed with the  Securities and Exchange
            Commission on March 31, 2003 (File No. 000-14879);

      3.    Amendment  No. 2 to our  Annual  Report on Form  10-K/A for the year
            ended  December 31, 2002, as filed with the  Securities and Exchange
            Commission on September 19, 2003 (File No. 000-14879);

      4.    Our Current  Report on Form 8-K,  dated  January 17, 2003,  as filed
            with the  Securities  and  Exchange  Commission  on January 17, 2003
            (File No. 000-14879);

      5.    Our Current  Report on Form 8-K,  dated  January 24, 2003,  as filed
            with the  Securities  and  Exchange  Commission  on January 27, 2003
            (File No. 000-14879);

      6.    Our Current  Report on Form 8-K,  dated April 8, 2003, as filed with
            the  Securities  and Exchange  Commission on April 9, 2003 (File No.
            000-14879);

      7.    Our Current  Report on Form 8-K,  dated May 14, 2003,  as filed with
            the  Securities  and Exchange  Commission  on May 14, 2003 (File No.
            000-14879);

      8.    Our  Quarterly  Report on Form 10-Q for the period  ended  March 31,
            2003, as filed with the  Securities  and Exchange  Commission on May
            14, 2003 (File No. 000-14879);

      9.    Our Current  Report on Form 8-K,  dated June 6, 2003,  as filed with
            the  Securities  and Exchange  Commission  on June 9, 2003 (File No.
            000-14879);

      10.   Our Current  Report on Form 8-K,  dated June 18, 2003, as filed with
            the  Securities  and Exchange  Commission  on July 3, 2003 (File No.
            000-14879);

      11.   Our Current  Report on Form 8-K,  dated July 10, 2003, as filed with
            the  Securities  and Exchange  Commission on July 11, 2003 (File No.
            000-14879);

      12.   Our Current  Report on Form 8-K dated July 14,  2003,  as filed with
            the  Securities  and Exchange  Commission on July 14, 2003 (File No.
            000-14879);

      13.   Our Current  Report on Form 8-K,  dated July 15, 2003, as filed with
            the  Securities  and Exchange  Commission on July 15, 2003 (File No.
            000-14879);

                                     - 29 -
14.   Our Current  Report on Form 8-K, dated August 1, 2003, as filed with
            the Securities  and Exchange  Commission on August 1, 2003 (File No.
            000-14879);

      15.   Our Current Report on Form 8-K, dated August 14, 2003, as filed with
            the Securities and Exchange  Commission on August 14, 2003 (File No.
            000-14829);

      16.   Our  Quarterly  Report on Form 10-Q for the  period  ended  June 30,
            2003, as filed with the Securities and Exchange Commission on August
            14, 2003 (File No. 000-14879);

      17.   The  description of our common stock  contained in our  Registration
            Statement on Form 8-A, as  supplemented  by the disclosure set forth
            in Exhibit  3.1 to our Form 10-Q  Quarterly  Report for the  quarter
            ended June 30, 2000 and Exhibit 3 to our Form 10-Q Quarterly  Report
            for the quarter ended June 30, 1996 (File No. 000-14879);

      18.   The description of our Series C Junior Participating Preferred Stock
            contained in Exhibit 1 to our Current  Report on Form 8-K filed with
            the  Securities  and Exchange  Commission on June 24, 1998 (File No.
            333-020015); and

      19.   All of our filings  pursuant to the  Exchange  Act after the date of
            filing the initial registration statement and prior to effectiveness
            of the registration statement.

      You may request a copy of these  documents,  which will be provided to you
at  no  cost,  by  writing  or  telephoning  us  using  the  following   contact
information:

                  Cytogen Corporation
                  650 College Road East, 3rd Floor
                  Princeton, New Jersey 08540
                  Attention:  Director, Legal
                  Telephone:  609-750-8222

      You should  rely only on the  information  incorporated  by  reference  or
provided in this prospectus or any prospectus supplement. We have not authorized
anyone  to  provide  you with  information  different  from  that  contained  or
incorporated  by  reference  in this  prospectus.  The  selling  stockholder  is
offering to sell, and seeking offers to buy,  shares of our common stock only in
jurisdictions where offers and sales are permitted. The information contained in
this prospectus is accurate only as of the date of this  prospectus,  regardless
of the time of delivery of this prospectus or of any sale of common stock.

                    INDEMNIFICATION OF DIRECTORS AND OFFICERS

      Subsection  (a) of Section 145 of the  Delaware  General  Corporation  Law
empowers a  corporation  to indemnify  any person who was or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding,
whether civil,  criminal,  administrative or investigative (other than an action
by or in the right of the  corporation)  by reason of the fact that he or she is
or was a director,  officer, employee or agent of the corporation,  or is or was
serving at the request of the  corporation as a director,  officer,  employee or
agent  of  another  corporation,  partnership,  joint  venture,  trust  or other
enterprise,  against expenses (including attorneys' fees), judgments,  fines and
amounts paid in  settlement  actually and  reasonably  incurred by him or her in
connection with such action, suit or proceeding if he or she acted in good faith
and in a manner he or she  reasonably  believed  to be in or not  opposed to the
best interests of the  corporation,  and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his or her conduct was unlawful.

                                     - 30 -
Subsection  (b) of Section 145 empowers a  corporation  to  indemnify  any
person  who  was or is a  party  or is  threatened  to be  made a  party  to any
threatened,  pending  or  completed  action  or suit by or in the  right  of the
corporation  to procure a judgment in its favor by reason of the fact that he or
she is or was a director,  officer, employee or agent of the corporation,  or is
or was  serving  at the  request  of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other  enterprise,  against  expenses  (including  attorneys' fees) actually and
reasonably  incurred by him or her in connection  with the defense or settlement
of such  action or suit if he or she  acted in good  faith and in a manner he or
she  reasonably  believed to be in or not opposed to the best  interests  of the
corporation and except that no  indemnification  shall be made in respect of any
claim,  issue or matter as to which such person  shall have been  adjudged to be
liable  to the  corporation  unless  and only to the  extent  that the  Court of
Chancery or the court in which such action or suit was brought  shall  determine
upon application that,  despite the adjudication of liability but in view of all
of the circumstances of the case, such person is fairly and reasonably  entitled
to indemnity for such  expenses  which the Court of Chancery or such other court
shall deem proper.

      Section 145 further provides that to the extent a director or officer of a
corporation has been successful in the defense of any action, suit or proceeding
referred to in subsection  (a) and (b) or in the defense of any claim,  issue or
matter  therein,  he or she shall be  indemnified  against  expenses  (including
attorneys'  fees) actually and  reasonably  incurred by him or her in connection
therewith;  that the indemnification provided by Section 145 shall not be deemed
exclusive  of any other rights to which the  indemnified  party may be entitled;
and that the scope of indemnification extends to directors, officers, employees,
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the  constituent  corporation
for another.  Section 145 also empowers a  corporation  to purchase and maintain
insurance  on behalf of a director  or officer of the  corporation  against  any
liability  asserted  against  him or her or  incurred  by him or her in any such
capacity  or  arising  out of his or her  status  as  such  whether  or not  the
corporation  would  have  the  power  to  indemnify  him  or  her  against  such
liabilities under Section 145.

      Section  102(b)(7)  of the  Delaware  General  Corporation  Law  enables a
corporation in its certificate of incorporation to limit the personal  liability
of members of its board of directors  for  violation  of a director's  fiduciary
duty of care. This section does not, however,  limit the liability of a director
for breaching his or her duty of loyalty, failing to act in good faith, engaging
in intentional misconduct or knowingly violating a law, authorizing a payment of
a dividend or approving a stock  repurchase  in violation of Delaware  Corporate
Law or from any transaction in which the director  derived an improper  personal
benefit.  This  section  also will have no  effect on claims  arising  under the
federal securities laws.

      The Company's  Certificate of  Incorporation  and By-Laws provide that the
Company shall indemnify  officers and directors and, to the extent  permitted by
the Board of Directors,  employees and agents of the Company, to the full extent
permitted  by and in the  manner  permissible  under  the  laws of the  State of
Delaware.  In addition,  the By-Laws  permit the Board of Directors to authorize
the Company to purchase and maintain  insurance  against any director,  officer,
employee or agent of the Company arising out of his capacity as such.

      Cytogen has obtained liability  insurance for the benefit of its directors
and officers  which  provides  coverage for losses of directors and officers for
liabilities  arising out of claims  against such persons  acting as directors or
officers  of  Cytogen  (or any  subsidiary  thereof)  due to any breach of duty,
neglect, error, misstatement, misleading statement, omission or act done by such
directors and officers, except as prohibited by law.

      Insofar as  indemnification  for liabilities  arising under the Securities
Act may be  permitted to  directors,  officers  and  controlling  persons of the
Registrant pursuant to the foregoing  provisions,  or

                                     - 31 -
otherwise,  the  Registrant has been advised that in the opinion of the SEC such
indemnification  is against public policy as expressed in the Securities Act and
is,  therefore,  unenforceable.  In the event  that a claim for  indemnification
against such  liabilities  (other than the payment by the Registrant of expenses
incurred or paid by a director,  officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as  expressed  in the  Securities  Act and will be  governed by the final
adjudication of such issue.

                                     - 32 -
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

      The SEC permits us to  "incorporate  by reference" the information we file
with the SEC, which means that we can disclose  important  information to you by
referring to those  documents.  We incorporate by reference the documents listed
below  and any  future  filings  made by us with the SEC under  Sections  13(a),
13(c), 14, and 15(d) of the Securities  Exchange Act of 1934, as amended,  until
the  filing  of a  post-effective  amendment  which  indicates  that all  Shares
registered  here have been sold or which  deregisters  all Shares then remaining
unsold.  The following  documents,  which are on file with the  Commission,  are
incorporated in this registration statement by reference:

      (a) Cytogen's  annual  report filed  pursuant to Section 13(a) or 15(d) of
the Securities Exchange Act of 1934, which includes audited financial statements
for our latest fiscal year for which such statements have been filed.

      (b) All other  reports  filed  pursuant  to Section  13(a) or 15(d) of the
Securities  Exchange Act of 1934 since the end of the fiscal year covered by the
document referred to in (a) above.

      (c) The description of Cytogen's common stock,  $0.01 par value,  which is
contained in our  registration  statement on Form 8-A filed under the Securities
Exchange Act of 1934, as supplemented by the disclosure set forth in Exhibit 3.1
to Cytogen's  Quarterly  Report on Form 10-Q for the quarter ended June 30, 2000
and Exhibit 3 to Cytogen's  Quarterly  Report on Form 10-Q for the quarter ended
June 30, 1996 and  including  any  amendment  or report filed for the purpose of
updating such description.

      All documents  subsequently  filed by the registrant  pursuant to Sections
13(a),  13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the
filing of a post-effective amendment which indicates that all securities offered
hereby have been sold or which deregisters all securities then remaining unsold,
shall be deemed to be incorporated by reference in this  registration  statement
and to be part  hereof  from  the  date of the  filing  of such  documents.  Any
statement  contained in a document  incorporated or deemed to be incorporated by
reference  herein shall be deemed to be modified or superseded  for the purposes
of this registration  statement to the extent that a statement  contained herein
or in any other  subsequently  filed  document  which also is or is deemed to be
incorporated by reference  herein  modifies or supersedes  such  statement.  Any
statement so modified or superseded  shall not be deemed,  except as so modified
or superseded, to constitute a part of this registration statement.

ITEM 4.  DESCRIPTION OF SECURITIES.

      Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

      Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

      Subsection  (a) of Section 145 of the  Delaware  General  Corporation  Law
empowers a  corporation  to indemnify  any person who was or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding,
whether civil,  criminal,  administrative or investigative (other than

                                      II-1
an action by or in the right of the  corporation)  by reason of the fact that he
or she is or was a director,  officer, employee or agent of the corporation,  or
is or was serving at the  request of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other enterprise, against expenses (including attorneys' fees), judgments, fines
and amounts paid in settlement actually and reasonably incurred by him or her in
connection with such action, suit or proceeding if he or she acted in good faith
and in a manner he or she  reasonably  believed  to be in or not  opposed to the
best interests of the  corporation,  and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his or her conduct was unlawful.

      Subsection  (b) of Section 145 empowers a  corporation  to  indemnify  any
person  who  was or is a  party  or is  threatened  to be  made a  party  to any
threatened,  pending  or  completed  action  or suit by or in the  right  of the
corporation  to procure a judgment in its favor by reason of the fact that he or
she is or was a director,  officer, employee or agent of the corporation,  or is
or was  serving  at the  request  of the  corporation  as a  director,  officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other  enterprise,  against  expenses  (including  attorneys' fees) actually and
reasonably  incurred by him or her in connection  with the defense or settlement
of such  action or suit if he or she  acted in good  faith and in a manner he or
she  reasonably  believed to be in or not opposed to the best  interests  of the
corporation and except that no  indemnification  shall be made in respect of any
claim,  issue or matter as to which such person  shall have been  adjudged to be
liable  to the  corporation  unless  and only to the  extent  that the  Court of
Chancery or the court in which such action or suit was brought  shall  determine
upon application that,  despite the adjudication of liability but in view of all
of the circumstances of the case, such person is fairly and reasonably  entitled
to indemnity for such  expenses  which the Court of Chancery or such other court
shall deem proper.

      Section 145 further provides that to the extent a director or officer of a
corporation has been successful in the defense of any action, suit or proceeding
referred to in subsection  (a) and (b) or in the defense of any claim,  issue or
matter  therein,  he or she shall be  indemnified  against  expenses  (including
attorneys'  fees) actually and  reasonably  incurred by him or her in connection
therewith;  that the indemnification provided by Section 145 shall not be deemed
exclusive  of any other rights to which the  indemnified  party may be entitled;
and that the scope of indemnification extends to directors, officers, employees,
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the  constituent  corporation
for another.  Section 145 also empowers a  corporation  to purchase and maintain
insurance  on behalf of a director  or officer of the  corporation  against  any
liability  asserted  against  him or her or  incurred  by him or her in any such
capacity  or  arising  out of his or her  status  as  such  whether  or not  the
corporation  would  have  the  power  to  indemnify  him  or  her  against  such
liabilities under Section 145.

      Section  102(b)(7)  of the  Delaware  General  Corporation  Law  enables a
corporation in its certificate of incorporation to limit the personal  liability
of members of its board of directors  for  violation  of a director's  fiduciary
duty of care. This section does not, however,  limit the liability of a director
for breaching his or her duty of loyalty, failing to act in good faith, engaging
in intentional misconduct or knowingly violating a law, authorizing a payment of
a dividend or approving a stock  repurchase  in violation of Delaware  Corporate
Law or from any transaction in which the director  derived an improper  personal
benefit.  This  section  also will have no  effect on claims  arising  under the
federal securities laws.

      The Company's  Certificate of  Incorporation  and By-Laws provide that the
Company shall indemnify  officers and directors and, to the extent  permitted by
the Board of Directors,  employees and agents of the Company, to the full extent
permitted  by and in the  manner  permissible  under  the  laws of the  State of
Delaware.  In addition,  the By-Laws  permit the Board of Directors to authorize
the Company

                                      II-2
to purchase and maintain  insurance against any director,  officer,  employee or
agent of the Company arising out of his capacity as such.

      Cytogen has obtained liability  insurance for the benefit of its directors
and officers  which  provides  coverage for losses of directors and officers for
liabilities  arising out of claims  against such persons  acting as directors or
officers  of  Cytogen  (or any  subsidiary  thereof)  due to any breach of duty,
neglect, error, misstatement, misleading statement, omission or act done by such
directors and officers, except as prohibited by law.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

      The  issuance of the Shares  being  reoffered  or resold  pursuant to this
Registration Statement were or will be deemed exempt from registration under the
Securities  Act in reliance upon either  Section 4(2) of the  Securities  Act as
transactions  not involving any public offering or Rule 701 under the Securities
Act as transactions made pursuant to a written  compensatory plan or pursuant to
a written contract relating to compensation.

ITEM 8.  EXHIBITS.

 Exhibit Number                            Description
 --------------   --------------------------------------------------------------

      5.1         Opinion of Hale and Dorr LLP.

      10.1        1995 Stock Option Plan,  as amended,  filed with the SEC as an
                  exhibit to the Company's Form 10-K for the year ended December
                  31, 2002, as amended, and incorporated herein by reference.

      23.1        Consent of KPMG LLP.

      23.2        Consent of PricewaterhouseCoopers LLP.

      23.3        Consent of Hale and Dorr LLP  (contained  in the opinion filed
                  as Exhibit 5.1).

      24          Power of Attorney  (contained  on the  signature  page of this
                  Registration Statement).

ITEM 9.  UNDERTAKINGS.

      a. Cytogen hereby undertakes:

            (1) To file,  during any  period in which  offers or sales are being
      made, a post-effective amendment to this registration statement:

            (i)   To include any prospectus  required by Section 10(a)(3) of the
                  Securities Act;

            (ii)  To reflect in the prospectus any facts or events arising after
                  the effective date of this registration statement (or the most
                  recent post-effective  amendment thereof) which,  individually
                  or in the  aggregate,  represent a  fundamental  change in the
                  information set forth in the registration statement; and

                                      II-3
(iii) To include any material  information  with respect to the plan
                  of distribution not previously  disclosed in this registration
                  statement or any material  change to such  information in this
                  registration statement;

      provided,  however,  that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
      if the information  required to be included in a post-effective  amendment
      by those  paragraphs  is  contained  in  periodic  reports  filed  with or
      furnished to the SEC by Cytogen pursuant to Section 13 or Section 15(d) of
      the Exchange Act that are  incorporated by reference in this  registration
      statement.

            (2) That,  for the purpose of  determining  any liability  under the
      Securities Act, each such post-effective amendment shall be deemed to be a
      new registration statement relating to the securities offered therein, and
      the  offering  of such  securities  at that time shall be deemed to be the
      initial bona fide offering thereof.

            (3)  To  remove  from  registration  by  means  of a  post-effective
      amendment any of the securities  being  registered  which remain unsold at
      the termination of the offering.

      b. The  undersigned  Registrant  hereby  undertakes  that, for purposes of
determining  any  liability  under  the  Securities  Act,  each  filing  of  the
Registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Exchange Act (and, where  applicable,  each filing of an employee benefit plan's
annual  report   pursuant  to  Section  15(d)  of  the  Exchange  Act)  that  is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration  statement relating to the securities offered therein,  and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

      c. Insofar as indemnification for liabilities arising under the Securities
Act may be  permitted to  directors,  officers  and  controlling  persons of the
Registrant pursuant to the foregoing  provisions,  or otherwise,  the Registrant
has been advised that in the opinion of the SEC such  indemnification is against
public  policy  as  expressed  in  the   Securities   Act  and  is,   therefore,
unenforceable.  In the  event  that a claim  for  indemnification  against  such
liabilities  (other than the payment by the  Registrant of expenses  incurred or
paid by a  director,  officer or  controlling  person of the  Registrant  in the
successful  defense of any  action,  suit or  proceeding)  is  asserted  by such
director,  officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as  expressed  in the  Securities  Act and will be  governed by the final
adjudication of such issue.

                                      II-4
SIGNATURES

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Registration  Statement  on  Form  S-8  to  be  signed  on  its  behalf  by  the
undersigned,  thereunto duly authorized, in the City of Princeton,  State of New
Jersey, on October 24, 2003.

                                    CYTOGEN CORPORATION

                                    By:  /s/ Michael D. Becker
                                       -----------------------------------------
                                       Michael D. Becker
                                       President and Chief Executive Officer
SIGNATURES AND POWER OF ATTORNEY

      We, the undersigned officers and directors of Cytogen Corporation,  hereby
severally constitute and appoint Michael D. Becker and Christopher P. Schnittker
and each of them singly, our true and lawful attorneys with full power to any of
them,  and to each of  them  singly,  to  sign  for us and in our  names  in the
capacities  indicated  below,  the  Registration  Statement  on Form  S-8  filed
herewith and any and all  pre-effective  and  post-effective  amendments to said
Registration  Statement  and  generally  to do all such  things  in our name and
behalf in our capacities as officers and directors to enable Cytogen Corporation
to comply with the provisions of the Securities Act of 1933, as amended, and all
requirements  of the Securities and Exchange  Commission,  hereby  ratifying and
confirming our signatures as they may be signed by our said attorneys, or any of
them, to said Registration Statement and any and all amendments thereto.

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
this  Registration  Statement  has been signed by the  following  persons in the
capacities and on the dates indicated.

           Signature                          Title                     Date
-------------------------------  -----------------------------  ----------------

/s/ Michael D. Becker            President, Chief Executive     October 24, 2003
-------------------------------  Officer and Director
Michael D. Becker                (Principal
                                 Executive Officer)

/s/ Christopher P. Schnittker    Vice President and Chief       October 24, 2003
-------------------------------  Financial   Officer
Christopher P. Schnittker        (Principal Financial and
                                 Accounting Officer)

/s/ John E. Bagalay, Jr.         Director                       October 24, 2003
-------------------------------
John E.  Bagalay, Jr.

/s/ Allen Bloom                  Director                       October 24, 2003
-------------------------------
Allen Bloom

                                 Director
-------------------------------
Stephen K.  Carter

/s/ James A. Grigsby             Director                       October 24, 2003
-------------------------------
James A. Grigsby

                                 Director
-------------------------------
Robert F.  Hendrickson

/s/ Kevin G. Lokay               Director                       October 24, 2003
-------------------------------
Kevin G. Lokay

/s/ H. Joseph Reiser             Director                       October 24, 2003
-------------------------------
H. Joseph Reiser
EXHIBIT INDEX

  Exhibit Number                            Description
 --------------   --------------------------------------------------------------

      5.1         Opinion of Hale and Dorr LLP.

      10.1        1995 Stock Option Plan,  as amended,  filed with the SEC as an
                  exhibit to the Company's Form 10-K for the year ended December
                  31, 2002, as amended, and incorporated herein by reference.

      23.1        Consent of KPMG LLP.

      23.2        Consent of PricewaterhouseCoopers LLP.

      23.3        Consent of Hale and Dorr LLP  (contained  in the opinion filed
                  as Exhibit 5.1).

      24          Power of Attorney  (contained  on the  signature  page of this
                  Registration Statement).