UNITED STATES

                       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): October 18, 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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          (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 8.01  OTHER EVENTS.

     On October 19, 2004,  Advanced  Magnetics,  Inc.  and  Cytogen  Corporation
announced  that  Advanced  Magnetics  has  submitted a complete  response to the
approvable letter received from the U.S. Food and Drug Administration  (FDA) for
Combidex(R),   Advanced  Magnetics'  investigational  molecular  imaging  agent.
Combidex  (ferumoxtran-10)  consists  of  iron  oxide  nanoparticles  for use in
conjunction with magnetic resonance imaging (MRI) to aid in the  differentiation
of cancerous from  non-cancerous  lymph nodes. The September 30, 2004 submission
has been  accepted  and assigned a user fee goal date of March 30, 2005 by which
date the FDA intends to review and act upon the submission.

     The full text of the October 19, 2004 press  release  issued in  connection
with the announcement is attached as Exhibit 99.1 to this Current Report on Form
8-K.

ITEM 9.01  FINANCIAL STATEMENTS AND EXHIBITS

(c) Exhibits.

        Exhibit No.       Description
        -----------       -----------
            99.1          Press  Release of Advanced Magnetics and Cytogen dated
                          October 19, 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:  October 19, 2004






                                  EXHIBIT INDEX


        Exhibit No.       Description
        -----------       -----------
            99.1          Press  Release of Advanced Magnetics and Cytogen dated
                          October 19, 2004