As filed with the Securities and Exchange Commission on October 4, 2002
                         Registration Statement No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                             ----------------------
                                    FORM S-3
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               CYTOGEN CORPORATION
         ---------------------------------------------------------------
             (Exact Name of Registrant as Specified in Its Charter)

           Delaware                                               22-2322400
---------------------------------                         ----------------------
   (State or Other Jurisdiction                              (I.R.S. Employer
of Incorporation or Organization)                         Identification Number)

                        650 College Road East, 3rd Floor
                           Princeton, New Jersey 08540
                                 (609) 750-8200
               -------------------------------------------------
          (Address, Including Zip Code, and Telephone Number, Including
             Area Code, of Registrant's Principal Executive Offices)

                            Lawrence R. Hoffman, Esq.
                   Vice President and Chief Financial Officer
                               Cytogen Corporation
                        650 College Road East, 3rd Floor
                           Princeton, New Jersey 08540
                                 (609) 750-8205
             -------------------------------------------------------
            (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)

                  -------------------------------------------
                                    Copy to:
                           Richard S. Mattessich, Esq.
                            Donald L. Novajosky, Esq.
                                Hale and Dorr LLP
                        650 College Road East, 4th Floor
                           Princeton, New Jersey 08540
                                 (609) 750-7600

  Approximate  date of  commencement  of  proposed  sale to  public:  As soon as
  practicable after this Registration Statement becomes effective.

      If the only  securities  being  registered  on this Form are being offered
  pursuant  to  dividend  or  interest  reinvestment  plans,  please  check  the
  following box. [ ]

      If any of the securities  being  registered on this Form are to be offered
  on a delayed or continuous basis pursuant to Rule 415 under the Securities Act
  of 1933,  other than  securities  offered only in connection  with dividend or
  interest reinvestment plans, check the following box. [X]

      If this Form is filed to register  additional  securities  for an offering
  pursuant to Rule 462(b) under the Securities  Act,  please check the following
  box and list the Securities Act  registration  statement number of the earlier
  effective registration statement for the same offering. _______.

      If this Form is a  post-effective  amendment filed pursuant to Rule 462(c)
  under the Securities  Act, check the following box and list the Securities Act
  registration  statement number of the earlier effective registration statement
  for the same offering. __________.

      If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.  [ ]

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





                                        CALCULATION OF REGISTRATION FEE
-----------------------------------------------------------------------------------------------------------


                                                              Proposed        Proposed
                                                               Maximum         Maximum
                                                Amount        Aggregate       Aggregate         Amount Of
                                                To Be           Price          Offering       Registration
Title Of Shares To Be Registered              Registered     Per Unit(1)       Price(1)            Fee
-----------------------------------------------------------------------------------------------------------
                                                                                     
Common stock,
   $.01 par value per share..............     1,276,994         $0.53        $676,806.82         $62.27
-----------------------------------------------------------------------------------------------------------


(1)      Estimated  solely for  purposes of  calculating  the  registration  fee
         pursuant to Rule 457(c) under the  Securities  Act of 1933, as amended,
         and based  upon the  average  of the high and low  prices on the Nasdaq
         National Market on September 27, 2002.

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


The Company hereby amends this  registration  statement on such date or dates as
may be  necessary  to delay its  effective  date until the Company  shall file a
further amendment which  specifically  states that this  registration  statement
shall  thereafter  become  effective  in  accordance  with  Section  8(a) of the
Securities  Act of  1933  or  until  the  registration  statement  shall  become
effective on such date as the Commission,  acting pursuant to said Section 8(a),
shall determine.






The  information  in this  prospectus  is not complete  and may be changed.  The
selling  stockholders  named in this  prospectus  may not sell these  securities
until  the  registration  statement  filed  with  the  Securities  and  Exchange
Commission  is  effective.  This  prospectus  is  not an  offer  to  sell  these
securities  and it is not  soliciting  offers  to buy  these  securities  in any
jurisdiction where the offer or sale is not permitted.

                 Subject to completion, dated October 4, 2002

PROSPECTUS

                               CYTOGEN CORPORATION

                        1,276,994 Shares of common stock


         This prospectus relates to resales of shares of our common stock, $0.01
par value per  share,  previously  issued by Cytogen  Corporation  to the former
shareholders and debtholders of Prostagen, Inc. in connection with the execution
of an Addendum to Stock Exchange  Agreement  among Cytogen  Corporation  and the
Shareholders  and  Debtholders  of  Prostagen,  Inc.  dated May 14, 2002,  and a
subsequent amendment dated August 13, 2002.

         We will not receive any proceeds from the sale of the shares.

         The  selling  stockholders  identified  in this  prospectus,  or  their
pledgees,  donees,  transferees or other  successors-in-interest,  may offer the
shares from time to time through  public or private  transactions  at prevailing
market  prices,  at prices  related to prevailing  market prices or at privately
negotiated prices.

         Our common  stock is traded on the  Nasdaq  National  Market  under the
symbol "CYTO." On September 27, 2002, the closing sale price of our common stock
on Nasdaq was $0.47 per share. You are urged to obtain current market quotations
for our common stock.


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

         Investing in our common stock involves a high degree of risk. See "Risk
Factors" commencing on page 3.

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

         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 4, 2002.




                                TABLE OF CONTENTS

--------------------------------------------------------------------------------
Prospectus Summary...........................................................  2

Cytogen Corporation..........................................................  2

The Offering.................................................................  2

Risk Factors.................................................................  3

   We Have A History Of Operating Losses And An Accumulated Deficit And
    Expect To Incur Losses In The Future.....................................  3

   We Are Heavily Dependent On Market Acceptance Of ProstaScint, Quadramet
    And BrachySeed For Near-Term Revenues....................................  3

   Our Functional Proteomics Program Is At An Early Stage Of Development.....  4

   There Is A Limited Market For Our Potential Functional Proteomics
    Products.................................................................  5

   The Reduced Workforce At AxCell May Not Be Able To Implement AxCell's
    Business Plan............................................................  5

   We Have Experienced Fluctuating Results Of Operations.....................  5

   We May Need To Raise Additional Capital Which May Not Be Available........  6

   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.....................................................  6

   Our PSMA Product Development Program is Novel And, Consequently,
    Inherently Risky.........................................................  7

   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......................................  8

   Competition In Our Field Is Intense And Likely To Increase................  8

   We Rely Heavily On Our Collaborative Partners.............................  9

   Our Business Could Be Harmed If Our Collaborative Arrangements Expire
    Or Are Terminated Early.................................................. 10

   The Termination Of One Or More License Agreements That Are Important
    In the Manufacture Of Our Current Products And New Product Research
    And Development Activities Would Harm Our Business....................... 10

   We Have Limited Sales, Marketing and Distribution Capabilities For Our
    Products................................................................. 10

   There Are Risks Associated With The Manufacture And Supply Of Our
    Products................................................................. 10

   Failure Of Consumers To Obtain Adequate Reimbursement From Third-Party
    Payors Could Limit Market Acceptance And Affect Pricing Of Our
    Products................................................................. 11

   If We Are Unable To Comply With Applicable Governmental Regulations, We
    May Not Be Able To Continue Our Operations............................... 12

   We Could Be Negatively Impacted By Future Interpretation Or
    Implementation Of Federal And State Fraud And Abuse Laws, Including
    Anti-Kickback Laws, The Federal State Law And Other Federal And State
    Anti-Referral Laws....................................................... 13

   We Depend On Attracting And Retaining Key Personnel....................... 14

   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................. 14

   Our Business Involves Environmental Risks That May Result In Liability.... 14

--------------------------------------------------------------------------------
                                      -i-


   Our Intellectual Property Is Difficult To Protect......................... 14

   We Cannot Be Certain That Our Security Measures Protect Our Unpatented
    Proprietary Technology................................................... 15

   We Are Currently Subject To Patent Litigation............................. 16

   If We Make Any Acquisitions, We Will Incur A Variety Of Costs And May
    Never Realize The Anticipated Benefits................................... 16

   Our Stock Price Has Been And May Continue To Be Volatile, And Your
    Investment In Our Stock Could Decline In Value Or Fluctuate
    Significantly............................................................ 16

   We Have Adopted Various Anti-Takeover Provisions Which May Affect the
    Market Price Of Our Common Stock......................................... 17

   The Liquidity Of Our Common Stock Could Be Adversely Affected If We Are
    Delisted From The Nasdaq National Market................................. 17

   A Large Number Of Our Shares Are Eligible For Future Sale Which May
    Adversely Impact The Market Price Of Our Common Stock.................... 18

   Because We Do Not Intend To Pay Any Cash Dividends On Our Shares Of
    Common Stock, Our Stockholders  Will Not Be Able To  Receive A Return
    On Their  Shares Unless They Sell Them................................... 20

Special Note Regarding Forward-Looking Statements............................ 20

Use of Proceeds.............................................................. 21

Selling Stockholders......................................................... 21

Plan of Distribution......................................................... 23

Legal Matters................................................................ 24

Experts...................................................................... 24

Where You Can Find More Information.......................................... 25

Information Incorporated By Reference........................................ 25
--------------------------------------------------------------------------------

         We have not authorized anyone to provide you with information different
from that contained or incorporated by reference in this prospectus. The selling
stockholders  are  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.



                                      -ii-



                               PROSPECTUS SUMMARY

This summary highlights  important features of this offering and the information
included or incorporated by reference in this prospectus.  This summary does not
contain all of the information  that you should consider before investing in our
common stock. You should read the entire  prospectus  carefully,  especially the
risks of investing in our common stock discussed under "Risk Factors."

                               CYTOGEN CORPORATION

         Cytogen Corporation is a 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);
BrachySeed(TM) I-125 and Pd-103, (uniquely designed, next-generation radioactive
seed implants for the treatment of localized prostate cancer);  and Quadramet(R)
(a therapeutic  agent marketed for the relief of bone pain in prostate and other
types of cancer).  We are evolving a pipeline of oncology product  candidates by
developing our prostate specific membrane antigen,  or PSMA technologies,  which
we exclusively licensed from Memorial Sloan-Kettering Cancer Center.

         AxCell Biosciences Corporation, a subsidiary of Cytogen Corporation, is
engaged in the  research and  development  of novel  biopharmaceutical  products
using its  portfolio  of  functional  proteomics  solutions  and  collection  of
proprietary signal transduction pathway information.  Through the systematic and
industrialized  measurement  of  protein-to-protein   interactions,   AxCell  is
assembling  ProChart(TM),  a proprietary database of signal transduction pathway
information that is relevant in a number of therapeutically important classes of
molecules  including  growth  factors,  receptors  and other  potential  protein
therapeutics  or  drug  targets.   AxCell's   database  content  and  functional
proteomics  tools  are  available  on a  non-exclusive  basis to  biotechnology,
pharmaceutical  and  academic  researchers.  AxCell is  continuing  its research
activities to further elucidate the role of novel proteins through both external
collaborations and data mining.

         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,  3rd Floor,  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.

         Cytogen(R), ProstaScint(R),  OncoScint(R),  Quadramet(R),  ProChart(TM)
database and the Cytogen and AxCell Biosciences Corporation logos are our marks.
All other trademarks, servicemarks or trade names referred to in this prospectus
are the property of their respective owners.

                                  THE OFFERING

Common Stock offered by selling
stockholders.......................   1,276,994 shares

Use of proceeds....................   Cytogen will not receive any proceeds from
                                      the sale of shares in this offering

Nasdaq National Market symbol......   CYTO


                                      -2-



                                  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. The risks and uncertainties described below are not
the only ones facing our company.  Additional risks and  uncertainties  may also
impair our business  operations.  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.

We have a history of operating losses since our inception.  We had a net loss of
$8.2  million for the six months ended June 30, 2002 and had a net loss of $12.1
million for the year ended  December 31, 2001.  The $8.2 million net loss during
the six months  ended June 30,  2002  included a  one-time,  non-cash  milestone
charge of $2.0  million  related  to the  progress of  dendritic  cell  prostate
cancer clinical trials at Northwest  Biotherapeutics,  Inc. We had a net loss of
$27.3  million for the year ended  December  31, 2000 which  included  one-time,
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 net income of $729,000 for the year ended  December 31,
1999 which  included a $3.3 million  non-operating  gain. We had an  accumulated
deficit  of  $348.9  million  as of June  30,  2002.  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.

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:

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

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

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

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

We Are Heavily  Dependent On Market  Acceptance  Of  ProstaScint,  Quadramet and
BrachySeed For Near-Term Revenues.

We expect ProstaScint, BrachySeed and Quadramet and to account for a significant
percentage  of our  product-related  revenues  in the near  future.  For the six
months ended June 30, 2002, revenues from ProstaScint,  BrachySeed and Quadramet
accounted for approximately 98% of our product related revenues.


                                      -3-

Because these 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:

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

     - 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 on the part of users.  We cannot assure you that additional
technologists  and physicians will make this commitment or otherwise accept this
product as part of their treatment practices.

Berlex  Laboratories,  Inc.  markets  Quadramet in the United States  through an
agreement with us entered into in October 1998. We cannot assure you that Berlex
will be able to successfully market Quadramet or that this agreement will result
in  significant  revenues  for us.  We  recently  obtained  marketing  rights to
Quadramet in Canada,  but have not yet implemented a selling program.  We cannot
assure you that Quadramet can be marketed effectively in Canada, or that it will
contribute significantly to our revenues.

We cannot assure you that Quadramet will be approved for additional indications,
due to  uncertainty  as to  efficacy  or safety for other  purposes,  regulatory
obstacles and physician preferences for existing or competing practices.

We cannot  assure you that  ProstaScint,  BrachySeed  or Quadramet  will achieve
additional  market  acceptance  on a timely  basis,  or at all. If  ProstaScint,
BrachySeed or Quadramet do not achieve broader market acceptance,  we may not be
able to generate sufficient revenue to become profitable.

Our Functional Proteomics Program Is At An Early Stage Of Development.

We are developing a functional proteomics program through our subsidiary, AxCell
Biosciences  Corporation.  This  technology  involves  new  approaches  to  drug
research and development and remains commercially  unproven.  Our technology and
development  focus is primarily  directed toward offering an  infrastructure  to
companies  for the  development  of drugs to treat a variety  of  complex  human
diseases.  There is  limited  understanding  generally  relating  to the role of
proteins in diseases, and few products based on protein interaction  discoveries
have been  developed  and  commercialized.  Even if our  proteomics  program  is
successful  in  identifying  and  validating  biological  targets,  there  is no
certainty  that we or our  customers  will be able to develop  or  commercialize
products to improve human health.

Our  technology  program  for  proteomics  is  still  in  the  early  stages  of
development.  We may not be able to populate our ProChart with  information that
is useful to  potential  customers in a timely  manner.  Even if we complete and
develop  successfully  our  proteomics  technology,  the  technology  may not be
accepted by, or be useful to, our potential customers.

In  addition,  the  success of our  proteomics  technology  will depend upon our
ability to use software  tools to generate data that relates  protein  signaling
pathways to a variety of other  bioinformatic data. Because of the complexity of
this  data,  we may not be able to detect  and  remedy  any  design  defects  or
software errors in our existing or future technologies, including databases.


                                      -4-



We  may  not  be  successful  in  addressing  or  mitigating   these  risks  and
uncertainties,  and, if we are not,  our  business  could be  significantly  and
adversely affected.

There Is A Limited Market For Our Potential Functional Proteomics Products.

Due to the specialized nature and anticipated cost of our proteomics  technology
and services,  there are a limited number of  pharmaceutical  and  biotechnology
companies that are potential customers.  In addition,  demand for our functional
proteomics technology and services is limited because:

     - our potential customers may decide to conduct in-house research rather
       than subscribe to our ProChart database;

     - our competitors may offer similar services at competitive prices;

     - we may not be able to service satisfactorily the needs of our potential
       or actual customers;

     - others  may  publicly  disclose  or  patent   proprietary   information
       contained in our  ProChart  (including  information  related to protein
       signaling  pathways  or target  candidates)  or  relating  to  prostate
       antigens or antibodies; and

     - technological innovations may be discovered that are more advanced than
       those used by or available to us.

We  may  not  be  successful  in  addressing  or  mitigating   these  risks  and
uncertainties,  and, if we are not,  our  business  could be  significantly  and
adversely affected.

The Reduced  Workforce At AxCell May Not Be Able To Implement  AxCell's Business
Plan.

In September  2002, we announced 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.  Although  we  believe  that  we have
retained  the  AxCell  personnel  who are key to  achieving  AxCell's  goals and
implementing  it's strategies,  we cannot be certain that such reduced workforce
will 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 it's goals.

We Have Experienced Fluctuating Results Of Operations.

Our results of operations  have  fluctuated on an annual and quarterly basis and
may fluctuate  significantly  from period to period in the future, due to, among
other factors:

     - variations in revenue from sales of and royalties from our products;

     - timing of regulatory approvals and other regulatory announcements
       relating to our products;

     - variations in our marketing, manufacturing and distribution channels;

     - timing of the acquisition and successful integration of complementary
       products and technologies;

     - timing of new product announcements and introductions by us and our
       competitors; and


                                      -5-



     - product obsolescence resulting from new product introductions by us or
       our competitors.

Many of these  factors  are  outside  our  control.  Due to one or more of these
factors, our results of operations may fall below the expectations of securities
analysts and  investors in one or more future  quarters.  If this  happens,  the
market price of our common stock could decline.

We May Need To Raise Additional Capital Which May Not Be Available.

We have  incurred  negative  cash  flows from  operations  since  inception.  We
expended, and will need to continue to expend, substantial funds to complete our
planned product development efforts, including our proteomics and PSMA programs.
Our future capital  requirements  and the adequacy of our available funds depend
on many factors, including:

     - successful commercialization of our products;

     - acquisition of complementary products and technologies;

     - magnitude, scope and results of our product development efforts;

     - progress of preclinical studies and clinical trials;

     - progress toward regulatory approval for our products;

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

     - competing technological and market developments; and

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

We may raise additional capital through public or private equity offerings, debt
financings or additional  collaborations and licensing arrangements.  Additional
financing may not be available to us when needed,  or, if available,  we may not
be able to obtain financing on terms favorable to us or our stockholders.  If we
raise additional capital by issuing equity securities,  the issuance will result
in ownership dilution to our stockholders.  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. If adequate  funds are not  available,  we may not be able to
conduct  research  activities,  preclinical  studies,  clinical  trials or other
activities  relating to the  successful  commercialization  of our products on a
timely  basis,   if  at  all,  with  the  result  that  our  business  could  be
significantly and adversely affected.

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 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.   These  products  have  not  yet  achieved
significant  commercial  success.


                                      -6-



Our  PSMA  and  proteomics  technologies  are  still  in  the  early  stages  of
development.   We  have  only  recently  begun  to  incorporate  our  proteomics
technology  into  commercialized  products.  We may be  unable  to  continue  to
successfully 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:

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

     - to ensure that our products are safe and effective;

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

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

     - to develop a sufficient market for our products; and

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

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:

     - the technologies we use will not be effective;

     - our product candidates will be unsafe;

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

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

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

In 1999, we entered into a joint venture with Progenics Pharmaceuticals, Inc. to
develop in vivo  immunotherapeutic  products  utilizing PSMA. The first of these
product  candidates is a therapeutic  prostate cancer vaccine utilizing the PSMA
gene and a vector  delivery  system  and the PSMA  protein  as a basis of immune
stimulation.  We are also  developing  through  this  venture an  antibody-based
immunotherapy  for  prostate  cancer.  The joint  venture  is owned  equally  by
Progenics  and us. We have  exclusively  licensed to the joint  venture  certain
immunotherapeutic applications of our PSMA patent rights and know-how. Progenics
has  funded  the  first $3  million  of  pre-clinical  development  costs of the


                                      -7-



program.  Beginning in December  2001,  Cytogen and  Progenics  began to equally
share the costs of the Joint Venture. Since that date, we have recognized 50% of
the Joint Venture's  operating  results,  which,  during the first six months of
2002 was a loss of approximately $1.1 million.  We expect our share of losses in
the PSMA  Development  Co. LLC to continue at even higher  levels in  subsequent
periods.

To our knowledge,  no therapeutic cancer vaccine has been demonstrated effective
or approved for marketing.  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.  We  cannot  assure  you  that  any  products  will  be
successfully  developed  from our PSMA  technology.  If we fail to develop  such
products for the reasons set forth above or for any other  reason,  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.  We
cannot assure you that the product  candidates we develop,  pursue or offer will
prove to be safe and effective, will receive the necessary regulatory approvals,
will not be precluded by proprietary  rights of third parties or will ultimately
achieve market  acceptance.  These product  candidates will require  substantial
additional investment,  laboratory development,  clinical testing and regulatory
approvals  prior to their  commercialization.  We cannot assure you that we will
not  experience   difficulties  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.  We
cannot  assure you that our  clinical  trials  will  demonstrate  the safety and
efficacy  of any  products or will 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. 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:

     - pharmaceutical companies;



                                      -8-


     - biotechnology companies;

     - bioinformatics companies;

     - diagnostic companies;

     - academic and research institutions; and

     - government agencies.

All of our  lines of  business  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.

Before we recover  development  expenses for our products and technologies,  the
products  or  technologies  may  become  obsolete  as a result of  technological
developments  by us or others.  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 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:

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

     - sub-license and marketing  agreement with Berlex  Laboratories,  Inc.
       relating to the Quadramet  technology which we licensed from The Dow
       Chemical Company;

     - agreement for manufacture of Quadramet by The DuPont Pharmaceuticals
       Company (formerly the  radiopharmaceuticals  division of The DuPont Merck
       Company);

     - marketing and platform development agreement with InforMax, Inc. related
       to our proteomics program;

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

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

     - marketing and distribution  agreement with Draxis Health, Inc.  and its
       subsidiary,  Draximage, Inc.  to market and distribute BrachySeed; and

     - marketing,  license and supply  agreements  with Advanced  Magnetics,
       Inc.  related to our oncology  product line for products currently
       subject to regulatory approval.


                                      -9-


Because our  collaborative  partners are  responsible  for certain of our sales,
marketing,  manufacturing  and  distribution  activities,  these  activities are
outside our direct control.  We cannot assure you that our partners will perform
their  obligations  under  these  agreements  with  us.  In the  event  that our
collaborative  partners  do not  successfully  market and sell our  products  or
breach  their  obligations  under  our  agreements,  our  products  may  not  be
commercially successful,  any success may be delayed and new product development
could be inhibited with the result that our business could be significantly  and
adversely affected.

Our Business  Could Be Harmed If Our  Collaborative  Arrangements  Expire Or Are
Terminated Early.

We cannot assure you that we will be able to maintain our existing collaborative
arrangements.  If they expire or are terminated,  we cannot assure you that they
will be renewed or that new arrangements  will be available on acceptable terms,
if at all.  In  addition,  we cannot  assure  you that any new  arrangements  or
renewals of existing  arrangements  will be successful,  that the parties to any
new or  renewed  agreements  will  perform  adequately  or that  any  former  or
potential collaborators will not compete with us.

We cannot assure you that our existing or future collaborations will lead to the
development of product  candidates or technologies  with  commercial  potential,
that we will be able to obtain  proprietary  rights or licenses for  proprietary
rights for our product  candidates or technologies  developed in connection with
these  arrangements  or that we will be able to ensure  the  confidentiality  of
proprietary rights and information developed in such arrangements or prevent the
public disclosure thereof.

The  Termination  Of One Or More License  Agreements  That Are  Important In The
Manufacture  Of Our Current  Products And New Product  Research And  Development
Activities Would Harm Our Business.

We are a  party  to  license  agreements  under  which  we  have  rights  to use
technologies  owned by other companies in the manufacture of our products and in
our  proprietary  research,  development  and  testing  processes.  We  are  the
exclusive  licensee  of  certain  patents  and patent  applications  held by the
University of North Carolina at Chapel Hill covering part of the technology used
in the proteomics program and of certain patents and patent applications held by
the Memorial  Sloan-Kettering  Institute  covering PSMA. We also depend upon the
enforceability  of our license  with The Dow  Chemical  Company  with respect to
Quadramet. If the licenses were terminated,  we may not be able to find suitable
alternatives to this technology on a timely basis or on reasonable  terms, if at
all. The loss of the right to use these technologies that we have licensed would
significantly and adversely affect our business.

We Have Limited Sales, Marketing And Distribution Capabilities For Our Products.

We have only recently established a sales force and have limited internal sales,
marketing and distribution  capabilities  for our products.  We depend on Berlex
Laboratories,  Inc. for the sale, marketing and distribution of Quadramet in the
United States. In locations outside the United States, we have not established a
selling presence.  If we are unable to establish and maintain significant sales,
marketing and distribution  efforts,  either internally or through  arrangements
with third parties, our business may be significantly and adversely affected.

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  through
third-party  manufacturers  in compliance  with regulatory  requirements  and at
costs acceptable to us. We cannot assure you that we will be able to arrange for
the  manufacture of our products on  commercially  reasonable  terms.  If we are
unable to  successfully  arrange for the manufacture of our products and product
candidates,  we will not be able to successfully  commercialize our products and
our business will be significantly and adversely affected.


                                      -10-


ProstaScint was manufactured at a cGMP compliant manufacturing facility operated
by Purdue. We had access to Purdue's facility for continued manufacturing of the
product until January 2002. We have built our inventory of  ProstaScint  to meet
our product  requirements  in the short term. We entered into a Development  and
Manufacturing  Agreement  with DSM in July 2000 which we intend will replace our
arrangement with Purdue with respect to ProstaScint. Notwithstanding the parties
obligations  to perform  under the  agreement  with DSM or to negotiate a supply
agreement  in good  faith,  we cannot be  certain  that DSM will  satisfactorily
perform its obligations thereunder or that the parties will be able to negotiate
a supply agreement on commercially  reasonable  terms, if at all. Our failure to
negotiate 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 DuPont  pursuant to an agreement with both Berlex
and Cytogen. Some components of Quadramet,  particularly  Samarium153 and EDTMP,
are  provided  to  DuPont  by  outside  suppliers.  Due  to  radioactive  decay,
Samarium153 must be produced on a weekly basis.  DuPont obtains its requirements
for Samarium153 from one supplier.  Alternative sources for these components may
not be readily available.  If DuPont 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.

We rely on Draxis as the sole supplier of  BrachySeed.  If Draxis fails to or is
unable to timely  supply  BrachySeed,  we could  experience  a material  adverse
effect on our business, financial condition and results of operations.

We and our  third-party  manufacturers  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 are 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 third-party manufacturers
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.  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.


                                      -11-


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.  We cannot assure you that our products will be
considered  cost-effective  and that reimbursement to consumers will continue to
be  available,  or will 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 Regulations,  We May Not
Be Able To Continue Our Operations.

Any products tested, manufactured or distributed by us or on our behalf pursuant
to  FDA  clearances  or  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 of clearances or approvals,  restrictions
on or injunctions  against  marketing our products based on our technology,  and
civil and criminal penalties.  We cannot assure you that we will not be required
to incur  significant costs to comply with laws and regulations in the future or
that  laws or  regulations  will  not  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 drug  development and regulatory  approval process is
lengthy, expensive, uncertain and subject to delays.

The regulatory risks we face also include the following:

     - 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;

     - 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;

     - 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.  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.  We
       cannot  assure you that such  approvals  will be  obtained  on a timely
       basis, or at all;

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

     - delays  or  rejections  may  be  encountered   based  upon  changes  in
       regulatory  agency policy during the period of drug development  and/or
       the period of review of any application for regulatory agency approval.


                                      -12-


       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.

We cannot  assure you that,  even after  this time and  expenditure,  regulatory
agency  approvals will be obtained for any compound or agent  developed by or in
collaboration with us. Moreover,  regulatory agency approval for a drug or agent
may entail  limitations  on the  indicated  uses that could limit the  potential
market for any such drug.  Furthermore,  if and when such  approval is obtained,
the marketing, manufacture,  labeling, storage 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,   suspension  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  manufacturing
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,  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 in submissions 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  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  Medicare or
Medicaid  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 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


                                      -13-


arising out of such action. We cannot assure you that we will not become subject
to such  litigation  or, if we are not  successful  in  defending  against  such
actions,  that  such  actions  will not 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 we cannot assure
you that we will be able to retain  existing  personnel  or  attract  and retain
additional highly qualified employees in the future.

We have an employee  retention  agreement with our President and Chief Executive
Officer,  H. Joseph Reiser,  Ph.D.,  which provides for vesting of stock options
for the purchase of shares of our common stock based on continued employment and
on the achievement of performance  objectives defined by the board of directors.
We do not have similar retention agreements with its other 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.  We cannot assure you that product
liability  claims will not be  asserted  against  us, our  collaborators  or our
licensees. While we currently maintain product liability insurance in amounts we
believe are  adequate,  we cannot assure you that such coverage will be adequate
to protect us against future product  liability claims or that product liability
insurance  will be  available  to us in the  future on  commercially  reasonable
terms,  if at all.  Furthermore,  we cannot  assure  you that we will be able to
avoid significant  product liability claims and adverse publicity.  If liability
claims  against  us exceed  our  financial  resources  we may have to curtail or
terminate our operations.

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.

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 its production and use.

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:


                                      -14-



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

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

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

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

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

     - 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,  and we cannot  assure  you as to the  degree of
protection  that will be  afforded  any  patents we are  issued or license  from
others.  Furthermore,  we cannot  assure you that others will not  independently
develop similar or alternative technologies,  duplicate any of our technologies,
or, if  patents  are  issued to us,  design  around  the  patented  technologies
developed by us. In addition,  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.  We cannot  assure you that,  if  challenged  by others in
litigation, the patents we have been issued, or which have been assigned or have
been licensed from others will not be found  invalid.  We cannot assure you that
our  activities  would  not  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:

     - subject us to significant liability to third parties;

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

     - require us to obtain licenses from third parties.

We cannot  assure  you that any  licenses  required  under any such  third-party
patents or proprietary rights would be made 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 us or our competitors'  pending patent  applications will
result in the issuance of valid  patents which may  significantly  and adversely
affect our business.

We Cannot Be Certain That Our Security Measures 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. We cannot assure you,
however,  that these agreements will provide  adequate  protection for our trade
secrets,  know-how or other proprietary  information or prevent any unauthorized
use or disclosure.


                                      -15-

We Are Currently Subject To Patent Litigation.

We are a defendant in a lawsuit filed  against us in the United  States  Federal
Court for the District of New Jersey by M. David  Goldenberg  and  Immunomedics,
Inc. This lawsuit was filed on March 16, 2000.  The  litigation  claims that our
ProstaScint  product infringes a patent  purportedly owned by Dr. Goldenberg and
licensed to Immunomedics. The patent sought to be enforced in the litigation has
now expired.  As a result, the claim, even if successful,  would not result in a
bar of the continued  sale of ProstaScint or affect any other of our products or
technology. However, given the uncertainty associated with litigation, we cannot
give any assurance that the litigation will not result in a material expenditure
to us.

If We Make Any  Acquisitions,  We Will  Incur A  Variety  Of Costs And May Never
Realize The Anticipated Benefits.

If  appropriate  opportunities  become  available,  we may  attempt  to  acquire
businesses,  technologies,  services or products that we believe are a strategic
fit with our business.  We currently  have no  commitments  or  agreements  with
respect to any  acquisitions.  If,  however,  we do undertake any transaction of
this sort, the process of integrating an acquired business,  technology, service
or product may result in operating  difficulties and expenditures and may absorb
significant  management  attention that would otherwise be available for ongoing
development  of our business.  Moreover,  we may never  realize the  anticipated
benefits of any  acquisition.  Future  acquisitions  could result in potentially
dilutive  issuances of equity  securities,  the  incurrence of debt,  contingent
liabilities  and  amortization  expenses  related to  intangible  assets.  These
factors  could  adversely   affect  our  results  of  operations  and  financial
condition, which could cause a decline in the market price of our common stock.

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:

     - results of clinical trials;

     - technological innovations or new commercial products;

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

     - changes in earnings;

     - changes in health care policies and practices;

     - developments or disputes concerning proprietary rights;

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

     - changes in general market conditions.


                                      -16-


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.

We Have Adopted  Various  Anti-Takeover  Provisions  Which May Affect The Market
Price Of Our Common Stock.

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.

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


                                      -17-

special meeting of our stockholders will be held on October 25, 2002 to consider
such  recommendation.  We believe the ability to effect a reverse stock split is
in the best interests of the Company and our stockholders and will help increase
the market price of our common stock above the minimum bid  requirement of $1.00
per  share  required  by  Nasdaq.  We  cannot  be  certain,  however,  that  our
stockholders will grant the Board of Directors  authority to effect such reverse
stock  split,  or that  even if such  authority  is  granted  and we do effect a
reverse  stock  split,  that the market price per share of our common stock will
increase as we anticipate.

In the  event  that we are  unable to regain  or  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. If we are unable
to comply with the minimum bid price requirement on or before November 12, 2002,
the Nasdaq staff will provide us with written notification that our common stock
will be delisted from the Nasdaq  National  Market.  At that time, we may appeal
Nasdaq's determination to a Listing Qualifications Panel.

Alternatively,  we may submit an  application  to  transfer  the  listing of our
common stock to the Nasdaq SmallCap Market. If such application is submitted and
approved,  we will be afforded an  additional  90-day  grace  period  which will
extend the  delisting  determination  until  February 11,  2003.  We may also be
eligible for an additional  180-day grace period which will extend the delisting
determination  until August 10, 2003 provided  that we meet the initial  listing
criteria for the Nasdaq SmallCap Market under  Marketplace  Rule  4310(c)(2)(A).
The Nasdaq SmallCap Market also has a $1.00 minimum bid price requirement.

We have not yet determined  whether to  voluntarily  transfer the listing of our
common  stock to the  Nasdaq  SmallCap  Market.  If we so decide  and submit the
necessary  transfer  application,  there can be no  assurance  that  Nasdaq will
approve our  application  or that if approved we will remain  compliant with the
applicable continued listing requirements.

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 24,
2002 we had  87,561,469  shares of common  stock  outstanding,  which  number of
shares: (i)


                                      -18-

includes  an  aggregate  of 2,417  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  500,000  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 346,446 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
4,813,752  shares of common stock are issuable upon the exercise of  outstanding
stock options and an additional 323,630 shares of common stock are issuable upon
the exercise of outstanding  warrants.  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  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 1,098,082  additional  shares of common stock  reserved for
future issuance under our current stock options plans,  75,699 additional shares
of common  stock  reserved  for  issuance  under  our  401(k)  Plan and  227,518
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 930,286  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
2,050,000  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  1,276,994
shares have been issued in 2002 and another $2.0 million worth of Cytogen common
stock may be issued if certain  milestones are achieved in the PSMA  development
programs.

In  addition,  on March 28,  2000,  we filed with the  Securities  and  Exchange
Commission  a shelf  registration  statement  on Form S-3  covering  six million
(6,000,000) shares of our common stock. 1,500,000 of such registered shares were
issued to Advanced Magnetics,  Inc. in connection with the parties entering into
a License and Marketing  Agreement in August 2000. An additional  500,000 of the
shares registered on that Form S-3 are currently being held in escrow and may be
released to Advanced  Magnetics  in the future in  accordance  with the terms of
such  License  and  Marketing  Agreement.  An  additional  902,601 of the shares
registered  on that form S-3 were  issued  to Acqua  Wellington  North  American
Equities Fund, Ltd. on September 29, 2000 in a private offering transaction.  An
additional  1,276,557 of the shares  registered  on that Form S-3 were issued to
Acqua  Wellington on February 5, 2001 pursuant to an equity  financing  facility
with Acqua Wellington that was subsequently terminated.  An additional 1,820,000
of the shares  registered on that Form S-3 were issued to the State of Wisconsin
Investment  Board on June 19,  2001 in a private  offering  transaction.  We are
contractually  obligated  to maintain  the  effectiveness  of such  registration
statement.

On October 25, 2001,  we filed with the  Securities  and  Exchange  Commission a
shelf  registration  statement  on Form S-3  covering  ten million  (10,000,000)
shares of our common stock.  2,970,665 and 4,166,700 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.

Availability  of a significant  number of additional  shares of our common stock
could depress the price of our common stock.


                                      -19-

Because  We Do Not  Intend  to Pay Any Cash  Dividends  On Our  Shares of Common
Stock,  Our  Stockholders  Will Not Be Able to Receive a Return on Their  Shares
Unless 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.  Unless  we pay  dividends,  our
stockholders  will not be able to receive a return on their  shares  unless they
sell them.

                SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

         This  prospectus  includes or incorporates  forward-looking  statements
within the meaning of Section 27A of the  Securities  Act 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,  including  among other
items, risks and uncertainties in:

     - our ability to successfully execute our business model;

     - our ability to compete successfully against direct and indirect
       competitors;

     - our ability to launch our proteomics program successfully;

     - market acceptance of and continuing demand for our products,  including
       programs designed to facilitate use of the products, such as the Partners
       in Excellence or PIE Program;

     - the timing and results of clinical studies and regulatory approvals;

     - demonstration over time of the efficacy and safety of our products;

     - our ability to develop new products;

     - the degree of competition from existing or new products;

     - success in obtaining marketing approvals for our products in Canada and
       Europe;


                                      -20-

     - our ability to protect our intellectual property, including patents and
       know-how;

     - our ability to access the capital markets in the near term and in the
       future to support our operations and for continued funding of existing
       projects and for the pursuit of new projects;

     - the ability to attract and retain personnel needed for business
       operations and strategic plans;

     - the decision by the majority of public and private insurance carriers on
       whether to  reimburse patients for our products;

     - the ability to attract and maintain, and the ultimate success of,
       strategic partnering arrangements, collaborations, and acquisition
       candidates; and

     - changing market conditions and shifts in the regulatory environment.

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

     - our most recent Annual Report on Form 10-K;

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

     - 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

         We will not receive any proceeds from the sale of shares by the selling
stockholders.

         The  selling  stockholders  will  pay any  underwriting  discounts  and
commissions  and expenses  incurred by the selling  stockholders  for brokerage,
accounting,  tax or legal services or any other expenses incurred by the selling
stockholders in disposing of the shares.  We will bear all other costs, fees and
expenses  incurred in effecting the  registration  of the shares covered by this
prospectus,  including,  without  limitation,  all registration and filing fees,
Nasdaq listing fees and fees and expenses of our counsel and our accountants.

                              SELLING STOCKHOLDERS

         In connection with our acquisition of Prostagen,  Inc. in June 1999, we
entered into a Stock Exchange Agreement with the stockholders and debtholders of
Prostagen,  Inc.,  collectively  referred to herein as the "Prostagen Partners."
Pursuant to the Stock  Exchange  Agreement,  we became  obligated to pay certain
amounts to the Prostagen Partners in both shares of our common stock and cash.

         On May 14,  2002,  we entered  into an Addendum  to the Stock  Exchange
Agreement  with  the  Prostagen  Partners.   Pursuant  to  such  Addendum,   our
obligations to make certain  payments  under the Stock  Exchange  Agreement have
been  clarified  and  the  shares  registered  hereunder  have  been  issued  in


                                      -21-


accordance with the Stock Exchange Agreement as clarified by such Addendum.  The
Addendum was subsequently amended on August 13, 2002.

         The following table sets forth, to our knowledge,  certain  information
about the selling stockholders as of September 6, 2002.

         Beneficial  ownership is determined in accordance with the rules of the
SEC, and includes voting or investment  power with respect to shares.  Shares of
common stock  issuable under stock options that are  exercisable  within 60 days
after  September 10, 2002 are deemed  outstanding  for computing the  percentage
ownership of the person holding the options but are not deemed  outstanding  for
computing  the  percentage  ownership  of any  other  person.  Unless  otherwise
indicated  below,  to our  knowledge,  all persons  named in the table have sole
voting and investment power with respect to their shares of common stock, except
to the extent authority is shared by spouses under applicable law. The inclusion
of any shares in this table  does not  constitute  an  admission  of  beneficial
ownership for the person named below.



                                                                     Number of
                                     Shares of Common Stock          Shares of           Shares of Common Stock
         Name of Selling          Beneficially Owned Prior to      Common Stock         to be Beneficially Owned
           Stockholder                    Offering (1)            Being Offered(1)           After Offering (1)
------------------------------    ----------------------------    ----------------    -----------------------------
                                     Number      Percentage (2)                          Number      Percentage (2)
                                  -----------    --------------                       -----------    --------------
                                                                                            
Misrock Holdings, L.P.........      363,498             *              363,498              0              *

C.C. Consulting A/S...........      261,718             *              261,718              0              *

Barbara G. Misrock (3)........      618,472             *              572,872           45,600            *

Michael Ian Sherman...........      139,807             *              139,807              0              *

FoxKiser Development
    Partners..................      162,112             *              162,112              0              *

New Hope Holdings, LP (4).....      238,159             *               58,159          180,000            *

Max Link......................       52,344             *               52,344              0              *

Gerard Klauer Mattison &
   Co., Inc. (5)..............       49,982             *               29,982           20,000            *


--------------------------
* Less than one percent.

(1)      We do not know when or in what amounts a selling  stockholder may offer
         shares for sale. The selling  stockholders might not sell any or all of
         the shares offered by this prospectus. Because the selling stockholders
         may offer all or some of the  shares  pursuant  to this  offering,  and
         because   there  are   currently   no   agreements,   arrangements   or
         understandings with respect to the sale of any of the shares, we cannot
         estimate  the  number of the  shares  that will be held by the  selling
         stockholders after completion of the offering. However, for purposes of
         this table,  we have assumed  that,  after  completion of the offering,
         none  of the  shares  covered  by this  prospectus  will be held by the
         selling stockholders.

(2)      Applicable  percentage  ownership  is based on  87,561,469  shares  of
         common stock  outstanding  as of September  24, 2002,  plus any common
         stock equivalent or convertible securities held or shares beneficially
         owned by each such holder.

(3)      Barbara G. Misrock is general partner of Misrock Holdings,  L.P., and,
         as such has the power to vote or direct  the vote of and to dispose of
         or direct the  disposition  of the shares  owned by Misrock  Holdings,


                                      -22-

         L.P. Ms.  Misrock  expressly  disclaims  beneficial  ownership of such
         shares,  except as to her proportionate  interest in Misrock Holdings,
         L.P.  Includes 254,974 shares of common stock held by
         Ms. Misrock in her individual capacity.

(4)      Includes  180,000  shares of common stock  otherwise  held by New Hope
         Holdings, LP.

(5)      Includes 20,000 shares of common stock otherwise held by Gerard Klauer
         Mattison & Co., Inc.

                              PLAN OF DISTRIBUTION

         The shares covered by this prospectus may be offered and sold from time
to time by the selling stockholders.  The term "selling  stockholders"  includes
donees,  pledgees,  transferees or other  successors-in-interest  selling shares
received after the date of this prospectus from a selling stockholder as a gift,
pledge, partnership distribution or other non-sale related transfer. The selling
stockholders  will act  independently  of us in making decisions with respect to
the timing,  manner and size of each sale. Such sales may be made on one or more
exchanges or in the  over-the-counter  market or otherwise,  at prices and under
terms then  prevailing or at prices  related to the then current market price or
in negotiated  transactions.  The selling  stockholders may sell their shares by
one or more of, or a combination of, the following methods:

     - purchases by a broker-dealer as principal and resale by such
       broker-dealer for its own account pursuant to this prospectus;

     - ordinary brokerage transactions and transactions in which the broker
       solicits purchasers;

     - block  trades  in which the broker-dealer so engaged will attempt to sell
       the  shares  as agent  but may position and resell a portion of the block
       as principal to  facilitate  the transaction;

     - an over-the-counter distribution in accordance with the rules of the
       Nasdaq National Market;

     - in privately negotiated transactions; and

     - in options transactions.

         In addition,  any shares that qualify for sale pursuant to Rule 144 may
be sold under Rule 144 rather than pursuant to this prospectus.

         To the extent required,  this prospectus may be amended or supplemented
from time to time to describe a specific  plan of  distribution.  In  connection
with  distributions  of the shares or otherwise,  the selling  stockholders  may
enter  into  hedging   transactions  with   broker-dealers  or  other  financial
institutions.  In connection  with such  transactions,  broker-dealers  or other
financial  institutions  may engage in short  sales of the  common  stock in the
course of hedging  the  positions  they assume with  selling  stockholders.  The
selling  stockholders  may also sell the common  stock short and  redeliver  the
shares to close out such short  positions.  The  selling  stockholders  may also
enter into option or other  transactions with  broker-dealers or other financial
institutions which require the delivery to such broker-dealer or other financial
institution   of  shares   offered  by  this   prospectus,   which  shares  such
broker-dealer  or  other  financial  institution  may  resell  pursuant  to this
prospectus (as supplemented or amended to reflect such transaction). The selling
stockholders  may also  pledge  shares  to a  broker-dealer  or other  financial
institution,  and,  upon  a  default,  such  broker-dealer  or  other  financial
institution,  may effect sales of the pledged shares pursuant to this prospectus
(as supplemented or amended to reflect such transaction).


                                      -23-

         In effecting  sales,  broker-dealers  or agents  engaged by the selling
stockholders may arrange for other broker-dealers to participate. Broker-dealers
or agents may receive  commissions,  discounts or  concessions  from the selling
stockholders in amounts to be negotiated immediately prior to the sale.

         In  offering  the  shares  covered  by  this  prospectus,  the  selling
stockholders  and  any   broker-dealers   who  execute  sales  for  the  selling
stockholders  may be deemed  to be  "underwriters"  within  the  meaning  of the
Securities  Act in  connection  with such  sales.  Any  profits  realized by the
selling  stockholders and the compensation of any broker-dealer may be deemed to
be underwriting discounts and commissions.

         In order to comply  with the  securities  laws of  certain  states,  if
applicable,  the  shares  must  be  sold  in  such  jurisdictions  only  through
registered or licensed  brokers or dealers.  In addition,  in certain states the
shares may not be sold unless they have been registered or qualified for sale in
the applicable  state or an exemption  from the  registration  or  qualification
requirement is available and is complied with.

         We have  advised the selling  stockholders  that the  anti-manipulation
rules of Regulation M under the Exchange Act may apply to sales of shares in the
market and to the activities of the selling  stockholders and their  affiliates.
In  addition,  we will make copies of this  prospectus  available to the selling
stockholders for the purpose of satisfying the prospectus delivery  requirements
of the Securities Act. The selling  stockholders may indemnify any broker-dealer
that  participates  in  transactions  involving  the sale of the shares  against
certain liabilities, including liabilities arising under the Securities Act.

         At the time a  particular  offer of  shares  is made,  if  required,  a
prospectus  supplement  will be  distributed  that will set forth the  number of
shares being  offered and the terms of the  offering,  including the name of any
underwriter,  dealer or agent, the purchase price paid by any  underwriter,  any
discount,  commission and other item  constituting  compensation,  any discount,
commission  or  concession  allowed or reallowed or paid to any dealer,  and the
proposed selling price to the public.

         We have agreed with the selling  stockholders to keep the  registration
statement of which this prospectus  constitutes a part effective until such time
as all of the shares covered by this  prospectus  have been disposed of pursuant
to and in accordance with the registration statement.

                                  LEGAL MATTERS

         The  validity  of the shares of common  stock  offered  hereby  will be
passed upon by Hale and Dorr LLP, Princeton, New Jersey.

                                     EXPERTS

         The consolidated  balance sheets of Cytogen  Corporation as of December
31, 2001 and 2000 and the consolidated  statements of operations,  stockholders'
equity  and cash  flows for each of the  years in the  three-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.  Such  financial  statements
have been audited by Arthur Andersen LLP,  independent  public  accountants,  as
indicated  in  their  report  with  respect  thereto,  and are  incorporated  by
reference  herein.  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  Andersen has not  consented to the  inclusion of
their  report  in this  prospectus,  you  will  not be able to  recover  against
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 Andersen or any  omissions  to state a material  fact  required to be
stated therein.


                                      -24-

                       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.

                      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, 2001,
          as filed with the  Securities  and  Exchange  Commission  on March 28,
          2002;

     (2)  Our Current  Report on Form 8-K dated  January 18, 2002, as filed with
          the Securities and Exchange Commission on January 24, 2002;

     (3)  Our Quarterly Report on Form 10-Q for the period ended March 31, 2002,
          as filed with the Securities and Exchange Commission on May 14, 2002;

     (4)  Our Current  Report on Form 8-K dated May 20, 2002,  as filed with the
          Securities and Exchange Commission on May 20, 2002, as amended on Form
          8-K/A dated May 20, 2002,  as filed with the  Securities  and Exchange
          Commission on May 22, 2002;

     (5)  Our Current  Report on Form 8-K dated May 24, 2002,  as filed with the
          Securities and Exchange Commission on May 24, 2002;

     (6)  Our Current  Report on Form 8-K dated May 29, 2002,  as filed with the
          Securities and Exchange Commission on May 31, 2002;

     (7)  Our Current  Report on Form 8-K dated June 4, 2002,  as filed with the
          Securities and Exchange Commission on June 4, 2002;

     (8)  Our Annual Report on Form 11-K for the period ended December 31, 2001,
          as filed with the Securities and Exchange Commission on June 27, 2002;

     (9)  Our Quarterly Report on Form 10-Q for the period  ended June 30, 2002,
          as filed with the  Securities  and Exchange Commission   on August 14,
          2002;

     (10) Our Current  Report on Form 8-K dated August 14,  2002,  as filed with
          the Securities and Exchange Commission on August 19, 2002;



                                      -25-



     (11) Our Current Report on Form 8-K dated September 16, 2002, as filed with
          the Securities and Exchange Commission on September 17, 2002.

     (12) 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;

     (13) 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; and

     (14) 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:  Lawrence R. Hoffman, Esq.
                                      Vice President and Chief Financial Officer
                          Telephone:  609-750-8200


         You  should  rely  on the  information  incorporated  by  reference  or
provided in this prospectus or any prospectus supplement. We have not authorized
anyone  else to provide  you with  different  information.  We are not making an
offer of these securities in any jurisdiction  where the offer is not permitted.
You should not assume that the  information in this prospectus or any prospectus
supplement  is accurate as of any date other than the date on the front of these
documents.


                                      -26-




                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.      Other Expenses of Issuance and Distribution.

         The following  table sets forth the various  expenses to be incurred in
connection  with the sale and  distribution of the securities  being  registered
hereby,  all  of  which  will  be  borne  by  Cytogen  Corporation  (except  any
underwriting  discounts  and  commissions  and expenses  incurred by the selling
stockholders  for  brokerage,  accounting,  tax or legal  services  or any other
expenses incurred by the selling  stockholders in disposing of the shares).  All
amounts  shown are  estimates  except the  Securities  and  Exchange  Commission
registration fee.

    Filing Fee - Securities and Exchange Commission .........    $     62.27

    Legal fees and expenses..................................    $ 15,000.00

    Accounting fees and expenses.............................    $  5,000.00
                                                                 -----------

          Total Expenses.....................................    $ 20,062.27
                                                                 ===========

Item 15.      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.

         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.


                                      II-1



         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, 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.

Item 16.     Exhibits.

         (a)   Exhibits

               5.1    Opinion of Hale and Dorr LLP.

               23.2   Consent of Hale and Dorr LLP (included in Exhibit 5.1).

               24.1   Power of Attorney. (Included on signature page).

Item 17.      Undertakings.

         The undersigned Registrant hereby undertakes:

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


                                      II-2



               (i)  To include any  prospectus  required by Section  10(a)(3) of
                    the  Securities  Act of 1933,  as amended  (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 this  Registration
                    Statement.  Notwithstanding  the foregoing,  any increase or
                    decrease  in  volume  of  securities  offered  (if the total
                    dollar  value of  securities  offered  would not exceed that
                    which was registered) and any deviation from the low or high
                    end of the estimated maximum offering range may be reflected
                    in the form of prospectus filed with the Commission pursuant
                    to Rule 424(b) if, in the  aggregate,  the changes in volume
                    and price  represent  no more than 20% change in the maximum
                    aggregate  offering price set forth in the  "Calculation  of
                    Registration  Fee"  table  in  the  effective   Registration
                    Statement; and

               (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  (1)(i)  and  (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
Commission  by the  Registrant  pursuant  to Section 13 or Section  15(d) of the
Securities  Exchange Act of 1934,  as amended  (the  "Exchange  Act"),  that are
incorporated by reference in this Registration Statement.

         (2) That,  for the purposes of  determining  any  liability  under the
Securities  Act,  each  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 the 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.

         The 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 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.

         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  indemnification  provisions  described  herein,  or
otherwise, the Registrant has been advised that in the opinion of the Securities
and  Exchange  Commission  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-3






                                   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-3 and has  duly  caused  this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly authorized,  in the City of Princeton,  State of New Jersey,  on October 4,
2002.

                                   CYTOGEN CORPORATION


                                   By: /s/ H. Joseph Reiser
                                      ------------------------------------------
                                      H. Joseph Reiser
                                      President and Chief Executive Officer







                        SIGNATURES AND POWER OF ATTORNEY

         We, the  undersigned  officers and  directors  of Cytogen  Corporation,
hereby severally constitute and appoint H. Joseph Reiser and Lawrence R. Hoffman
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-3 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/ H. Joseph Reiser                 President, Chief Executive Officer and         October 4, 2002
-----------------------------------  Director (Principal Executive Officer)
H. Joseph Reiser

/s/ Lawrence R. Hoffman              Vice President and Chief Financial Officer     October 4, 2002
-----------------------------------  (Principal Financial and Accounting Officer)
Lawrence R. Hoffman

/s/ John E. Bagalay, Jr.             Director                                       October 4, 2002
-----------------------------------
John E. Bagalay, Jr.

/s/ Stephen K. Carter                Director                                       October 2, 2002
-----------------------------------
Stephen K. Carter

/s/ James A. Grigsby                 Director                                       October 4, 2002
-----------------------------------
James A. Grigsby

/s/ Robert F. Hendrickson            Director                                       October 4, 2002
-----------------------------------
Robert F. Hendrickson

/s/ Kevin G. Lokay                   Director                                       October 2, 2002
-----------------------------------
Kevin G. Lokay





                                  EXHIBIT INDEX

EXHIBIT
NUMBER                             DESCRIPTION
-------  ----------------------------------------------------------------------
  5.1    Opinion of Hale and Dorr LLP.

 23.2    Consent of Hale and Dorr LLP (included in Exhibit 5.1 filed herewith).

 24.1    Power of Attorney (included on signature page).