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): December 13, 2005
                                                         -----------------

                               CYTOGEN CORPORATION
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               (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
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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 1.01    ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT; ITEM 8.01 OTHER EVENTS.

     On December 13, 2005,  Cytogen  Corporation,  a Delaware  corporation  (the
"Company"),  announced that it has entered into a Securities  Purchase Agreement
(the "Securities Purchase Agreement") with certain  institutional  investors for
the sale of  3,729,556  shares of its  common  stock  and  932,389  warrants  to
purchase shares of its common stock at a unit price of $3.56 per unit, through a
registered  direct  offering.  The Warrants have an exercise  price of $4.25 per
share  and are not  exercisable  until  six  months  after  the  closing  of the
transaction.   The   transaction  is  expected  to  provide  gross  proceeds  of
approximately  $13.3 million to Cytogen before  deducting costs  associated with
the  offering,  and  will be used  primarily  for  general  corporate  purposes,
including the selling,  marketing and clinical development of Cytogen's products
and product  candidates.  The parties expect to close the transaction as soon as
possible.  The placement  agent in this  transaction  will receive  compensation
consisting  of (i) a cash fee equal to 5% of the  aggregate  gross  proceeds and
(ii) warrants to purchase shares equal to 5% of the aggregate shares sold in the
transaction (collectively with the warrants described above, the "Warrants").

     The shares of common  stock and the shares of common stock  underlying  the
Warrants  offered by the Company in this  transaction  will be  registered  upon
issuance under the Company's existing shelf Registration  Statement (referred to
below).  The Company is not  listing the  Warrants on an exchange or any trading
system and does not expect that a trading market for the Warrants will develop.

     On November 5, 2004, the Company filed a registration  statement  (File No.
333-120262) (the  "Registration  Statement") on Form S-3 with the Securities and
Exchange Commission (the "Commission")  relating to the public offering pursuant
to Rule 415 under the Securities Act of 1933, as amended,  of up to an aggregate
of $70,000,000 of debt securities,  common stock,  preferred stock, warrants and
units  of the  Company.  The  Commission  declared  the  Registration  Statement
effective on November 14, 2004.

     A copy of each of the form of Securities  Purchase  Agreement,  the form of
Common  Stock  Purchase  Warrant and the related  press  release of the Company,
dated December 13, 2005,  are filed  herewith as Exhibits  10.1,  10.2 and 99.1,
respectively,   and  are  incorporated   herein  by  reference.   The  foregoing
description of the transaction and the documents related thereto is qualified in
its entirety by reference to such Exhibits.






ITEM 9.01    FINANCIAL STATEMENTS AND EXHIBITS

(c) Exhibits.

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

           10.1           Form of Securities Purchase Agreement by and among the
                          Company and the Purchasers dated December 13, 2005.

           10.2           Form of  Common Stock Purchase  Warrant issued  by the
                          Company in favor of each Purchaser dated  December 13,
                          2005.

           99.1           Press Release of the Company dated December 13, 2005.





                                   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:   December 14, 2005






                                  EXHIBIT INDEX


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

           10.1           Form of Securities Purchase Agreement by and among the
                          Company  and the Purchasers dated December 13, 2005.

           10.2           Form of Common  Stock Purchase  Warrant  issued by the
                          Company in favor of each Purchaser dated  December 13,
                          2005.

           99.1           Press Release of the Company dated December 13, 2005.