UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934


       Date of report (Date of earliest event reported): November 19, 2004
                                                         -----------------

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

          Delaware                        000-14879                22-2322400
------------------------------   ------------------------    -------------------
(State or Other Jurisdiction     (Commission File Number)     (I.R.S. Employer
        of Incorporation)                                    Identification No.)

  650 College Road East, CN 5308, Suite 3100, Princeton, NJ           08540
--------------------------------------------------------------   ---------------
         (Address of Principal Executive Offices)                  (Zip Code)

       Registrant's telephone number, including area code: (609) 750-8200
                                                           --------------


--------------------------------------------------------------------------------
          (Former Name or Former Address, if Changed Since Last Report)

     Check the  appropriate  box below if the Form 8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

     |_|  Written  communications  pursuant to Rule 425 under the Securities Act
(17 CFR 230.425)

     |_|  Soliciting  material  pursuant to Rule 14a-12  under the  Exchange Act
(17 CFR 240.14a-12)

     |_|  Pre-commencement  communications pursuant  to Rule 14d-2(b) under  the
Exchange Act (17 CFR 240.14d-2(b))

     |_|  Pre-commencement  communications pursuant  to Rule 13e-4(c) under  the
Exchange Act (17 CFR 240.13e-4(c))




ITEM 1.01  ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.

     On November 19, 2004,  Cytogen  Corporation  (the  "Company")  entered into
Addendum No. 2 (the "Addendum") to the Stock Exchange Agreement dated as of June
15, 1999, as amended (the  "Agreement"),  among the Company and the stockholders
and  debtholders  (collectively,  the "Prostagen  Partners") of Prostagen,  Inc.
("Prostagen").  The Company  entered into the Agreement in  connection  with the
Company's  acquisition  of  Prostagen,  and is obligated to make payments to the
Prostagen  Partners if certain  milestones  are achieved in the  dendritic  cell
therapy and PSMA development programs. All terms not specifically defined herein
shall have the meaning ascribed to them in the Addendum or the Agreement.

     The Addendum was  effective  immediately  and  provides  that,  among other
things,  in  satisfaction  of its  obligations  to the Prostagen  Partners under
Paragraphs  1.6(b) and (d) of the  Agreement,  the Company  shall deliver to the
representative  of the Prostagen  Partners:  (i) 50,000 shares of Cytogen common
stock within ten business  days of the date of the  Addendum;  (ii)  $500,000 of
shares of Cytogen  common stock within ten business days after the completion by
PSMA Development  Company,  LLC (or any entity with technology licensed from the
Company) of a Phase I clinical trial for  immunotherapy  for prostate  cancer if
such trial establishes  safety; and (iii) $1,000,000 of shares of Cytogen common
stock within ten business  days after the  enrollment of the first patient after
the date hereof by PSMA Development  Company, LLC (or any entity with technology
licensed  from the  Company) in a Phase III or combined  Phase  II-III  clinical
trial for immunotherapy for prostate cancer.

     The Company intends to issue shares of its common stock, in satisfaction of
its obligations  under the Addendum,  that will be registered under its existing
shelf  registration  statement  on Form S-3  (Reg.  No.  333-110040),  which was
declared  effective by the  Securities  and Exchange  Commission  on October 30,
2003.

     The foregoing  descriptions of the Addendum and the Agreement are qualified
in their entirety by reference to such Exhibits.




ITEM 9.01  FINANCIAL STATEMENTS AND EXHIBITS

(c) Exhibits.

        Exhibit No.       Description
        -----------       -----------

            10.1          Addendum No. 2 to Stock Exchange  Agreement Among  the
                          Company  and  the   Stockholders  and  Debtholders  of
                          Prostagen, Inc.  Filed herewith.

            10.2          Addendum to Stock  Exchange  Agreement  among  Cytogen
                          Corporation  and the  Stockholders  and Debtholders of
                          Prostagen,  Inc. dated as of May 14, 2002, and amended
                          as of August  13,  2002.  Filed as an  exhibit  to the
                          Company's  Quarterly  Report on Form 10-Q,  filed with
                          the  Commission on August 14, 2002,  and  incorporated
                          herein by reference.

            10.3          Stock Exchange Agreement  Among  the Company  and  the
                          Stockholders and Debtholders of Prostagen, Inc.  Filed
                          as an exhibit to the Company's Registration  Statement
                          on  Form S-3 dated July 19, 1999, as amended (Reg. No.
                          333-83215), and incorporated herein by reference.






                                   SIGNATURES


     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

                                                CYTOGEN CORPORATION



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

Dated:   November 22, 2004






                                  EXHIBIT INDEX


        Exhibit No.    Description
        -----------    -----------

           10.1        Addendum  No. 2 to Stock Exchange Agreement Among Cytogen
                       Corporation  and  the  Stockholders  and  Debtholders  of
                       Prostagen, Inc.  Filed herewith.

           10.2        Addendum  to  Stock  Exchange  Agreement  among   Cytogen
                       Corporation  and  the  Stockholders  and  Debtholders  of
                       Prostagen, Inc.  dated as of May 14, 2002, and amended as
                       of  August 13, 2002. Filed as an exhibit to the Company's
                       Quarterly  Report on Form 10-Q, filed with the Commission
                       on August 14, 2002, and incorporated herein by reference.

           10.3        Stock  Exchange  Agreement  Among  the  Company  and  the
                       Stockholders and Debtholders of Prostagen, Inc.  Filed as
                       an  exhibit to  the Company's Registration  Statement  on
                       Form  S-3  dated  July  19, 1999,  as  amended  (Reg. No.
                       333-83215) and incorporated herein by reference.