SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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                                    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): June 25, 2004
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                               CYTOGEN CORPORATION
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               (Exact Name of Registrant as Specified in Charter)

           Delaware                     000-14879                 22-2322400
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(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
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         (Address of Principal Executive Offices)                     (Zip Code)

       Registrant's telephone number, including area code: (609) 750-8200
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ITEM 5.     OTHER EVENTS.

         On June 25, 2004,  Cytogen  Corporation,  a Delaware  corporation  (the
"Company")  and Advanced  Magnetics,  Inc.  announced  that  Advanced  Magnetics
submitted a response to the  approvable  letter  received from the United States
Food   and   Drug   Administration   for   Combidex(R),    Advanced   Magnetics'
investigational  molecular  imaging  agent to aid in the diagnosis of metastatic
lymph nodes.

         A copy  of the  related  press  release  of the  Company  and  Advanced
Magnetics,  dated June 25,  2004,  is filed  herewith  as Exhibit  99.1,  and is
incorporated herein by reference.  The foregoing description is qualified in its
entirety by reference to such Exhibit.

ITEM 7.     FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS.

         (c) Exhibits.

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

                 99.1        Press release of the Company and Advanced Magnetics
                             dated June 25, 2004.






                                   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:   June 25, 2004






                                  EXHIBIT INDEX


              Exhibit No.    Description
              -----------    -----------
                 99.1        Press release of the Company and Advanced Magnetics
                             dated June 25, 2004.