content: 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): April 20, 2006
                                                            --------------
  
                                 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))
  
  
  <PAGE>
  
  
  ITEM 1.01    ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT
  
  
       On April 20, 2006, Cytogen  Corporation  ("Cytogen")  announced that it had
  entered into a Membership Interest Purchase Agreement (the "Purchase Agreement")
  with Progenics  Pharmaceuticals,  Inc.  ("Progenics")  providing for the sale to
  Progenics of Cytogen's 50% ownership  interest in PSMA  Development  Company LLC
  ("PDC"),  Cytogen's  joint venture with Progenics for the development of in vivo
  cancer immunotherapies based on prostate-specific membrane antigen (PSMA).
  
       In  addition,  on April 20,  2006,  Cytogen  entered  into an  Amended  and
  Restated  PSMA/PSMP License  Agreement (the "License  Agreement") with Progenics
  and PDC pursuant to which Cytogen licensed PDC rights in the Field, as such term
  is defined in the License Agreement.
  
       Under the terms of such agreements, Cytogen sold its 50% interest in PDC to
  Progenics  for an  upfront  cash  payment  of $13.2  million,  potential  future
  milestone  payments totaling up to $52 million payable upon regulatory  approval
  and commercialization of PDC products,  and an undisclosed royalty on future PDC
  product sales.
  
       Attached hereto and  incorporated by reference  herein as Exhibit 99.1 is a
  copy of the related  press  release of Cytogen,  dated April 24, 2006. A copy of
  the License  Agreement and the Purchase  Agreement  will be filed as exhibits to
  Cytogen's upcoming quarterly Report on Form 10-Q for the quarter ended March 31,
  2006.
  
  ITEM 2.01    COMPLETION OF ACQUISITION OR DISPOSITION OF ASSETS
  
       On April  20,  2006,  Cytogen  entered  into the  Purchase  Agreement  with
  Progenics  providing  for the sale to Progenics of the  Company's  50% ownership
  interest in PDC, the company's  joint venture with Progenics for the development
  of in vivo cancer  immunotherapies  based on PSMA. Cytogen sold its 50% interest
  in the LLC to Progenics in exchange for the payment of $13.2  million in cash to
  Cytogen.
  
       Attached hereto and  incorporated by reference  herein as Exhibit 99.1 is a
  copy of the related  press  release of Cytogen,  dated April 24, 2006. A copy of
  the Purchase  Agreement  will be filed as an exhibit to the  Company's  upcoming
  quarterly  Report on Form 10-Q for the quarter ended March 31, 2006. The Company
  will file pro forma financial information on an amendment to this Form 8-K.
  
  ITEM 9.01    FINANCIAL STATEMENTS AND EXHIBITS
  
  (d)    Exhibits.
  
         Exhibit No.       Description
         -----------       -----------
  
            99.1           Press Release of Cytogen dated April 24, 2006.
  
  
  <PAGE>
  
  
                                     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:   April 26, 2006
  
  
  <PAGE>
  
  
                                    EXHIBIT INDEX
  
  
         Exhibit No.       Description
         -----------       -----------
  
             99.1          Press Release of Cytogen dated April 24, 2006.
metadata_documents: [{"type": "8-K", "sequence": "1", "filename": "form8k_progenics042606.txt", "description": "FORM 8-K - FOR PROGENICS SALE", "secsgml_size_bytes": 5682}]
metadata_filer: {"company-data": {"conformed-name": "CYTOGEN CORP", "cik": "0000725058", "assigned-sic": "2834", "irs-number": "222322400", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-14879", "film-number": "06780396"}, "business-address": {"street1": "650 COLLEGE RD EAST STE 3100", "city": "PRINCETON", "state": "NJ", "zip": "08540", "phone": "6099878200"}, "mail-address": {"street1": "650 COLLEGE RD EAST STE 3100", "city": "PRINCETON", "state": "NJ", "zip": "08540"}}
text: 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): April 20, 2006
                                                            --------------
  
                                 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 April 20, 2006, Cytogen  Corporation  ("Cytogen")  announced that it had
  entered into a Membership Interest Purchase Agreement (the "Purchase Agreement")
  with Progenics  Pharmaceuticals,  Inc.  ("Progenics")  providing for the sale to
  Progenics of Cytogen's 50% ownership  interest in PSMA  Development  Company LLC
  ("PDC"),  Cytogen's  joint venture with Progenics for the development of in vivo
  cancer immunotherapies based on prostate-specific membrane antigen (PSMA).
  
       In  addition,  on April 20,  2006,  Cytogen  entered  into an  Amended  and
  Restated  PSMA/PSMP License  Agreement (the "License  Agreement") with Progenics
  and PDC pursuant to which Cytogen licensed PDC rights in the Field, as such term
  is defined in the License Agreement.
  
       Under the terms of such agreements, Cytogen sold its 50% interest in PDC to
  Progenics  for an  upfront  cash  payment  of $13.2  million,  potential  future
  milestone  payments totaling up to $52 million payable upon regulatory  approval
  and commercialization of PDC products,  and an undisclosed royalty on future PDC
  product sales.
  
       Attached hereto and  incorporated by reference  herein as Exhibit 99.1 is a
  copy of the related  press  release of Cytogen,  dated April 24, 2006. A copy of
  the License  Agreement and the Purchase  Agreement  will be filed as exhibits to
  Cytogen's upcoming quarterly Report on Form 10-Q for the quarter ended March 31,
  2006.
  
  ITEM 2.01    COMPLETION OF ACQUISITION OR DISPOSITION OF ASSETS
  
       On April  20,  2006,  Cytogen  entered  into the  Purchase  Agreement  with
  Progenics  providing  for the sale to Progenics of the  Company's  50% ownership
  interest in PDC, the company's  joint venture with Progenics for the development
  of in vivo cancer  immunotherapies  based on PSMA. Cytogen sold its 50% interest
  in the LLC to Progenics in exchange for the payment of $13.2  million in cash to
  Cytogen.
  
       Attached hereto and  incorporated by reference  herein as Exhibit 99.1 is a
  copy of the related  press  release of Cytogen,  dated April 24, 2006. A copy of
  the Purchase  Agreement  will be filed as an exhibit to the  Company's  upcoming
  quarterly  Report on Form 10-Q for the quarter ended March 31, 2006. The Company
  will file pro forma financial information on an amendment to this Form 8-K.
  
  ITEM 9.01    FINANCIAL STATEMENTS AND EXHIBITS
  
  (d)    Exhibits.
  
         Exhibit No.       Description
         -----------       -----------
  
            99.1           Press Release of Cytogen dated April 24, 2006.
  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:   April 26, 2006
  EXHIBIT INDEX
  
         Exhibit No.       Description
         -----------       -----------
  
             99.1          Press Release of Cytogen dated April 24, 2006.