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): March 24, 2005

                               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))


     Advanced Magnetics, Inc., the developer of Combidex(R) which is exclusively
licensed to Cytogen Corporation for marketing in the United States, has informed
Cytogen that Advanced Magnetics received an approvable letter from the U.S. Food
and Drug Administration for Combidex.



     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/ William J. Thomas
                                               William J. Thomas
                                               Senior Vice President and General

Dated:   March 24, 2005