**SETTLEMENT
      AND RELEASE AGREEMENT**





THIS
      SETTLEMENT AND RELEASE AGREEMENT (the “Settlement Agreement”), made and entered
      into this 15th day of February, 2007, is by and between Cytogen Corporation
      (“Cytogen”) and Advanced Magnetics, Inc. (“AMI”)(collectively, the
“Parties”).





RECITALS





WHEREAS,
      Cytogen and AMI currently are engaged in a dispute, and are parties to a certain
      civil action pending in the Superior Court Department of the Trial Court of
      the
      Commonwealth of Massachusetts (the “Court”), entitled Cytogen Corporation v.
      Advanced Magnetics, Inc., Civil Action No. 06-0313-BLS2 (hereinafter the
“Lawsuit”);





WHEREAS,
      in the Lawsuit, the Parties have asserted various claims and counterclaims
      against each other;





WHEREAS,
      the Parties deny the allegations set forth by the other in the
      Lawsuit;





WHEREAS,
      the Parties to this Settlement Agreement recognize that in order to avoid
      further costs and uncertainty in connection with the Lawsuit, it is in their
      respective best interests to compromise and thereby terminate and conclude
      the
      Lawsuit and all disputes between them.





NOW,
      THEREFORE, in consideration of the mutual covenants expressed herein and other
      good and valuable consideration, the receipt and sufficiency of which is hereby
      acknowledged, the undersigned parties to this Settlement Agreement mutually
      agree and contract with each other, as follows:





1.
            SETTLEMENT
                PAYMENT.





By
      no
      later than three (3) business days following the full execution of this
      Settlement Agreement, AMI shall pay to Cytogen a sum total of four million
      U.S.
      dollars (USD$4,000,000.00) by certified check or wire transfer (the “Settlement
      Amount”).










2.           RELEASE
      OF ESCROWED SHARES.





By
      no
      later than ten (10) business days following the full execution of this
      Settlement Agreement, the Parties shall jointly and in writing inform
      ChaseMellon Shareholder Services, L.L.C. (the “Escrow Agent”) that the License
      Agreement has been mutually terminated by the Parties and instruct the Escrow
      Agent to release and transfer to Cytogen the 50,000 shares (formerly 500,000
      shares) of Cytogen stock (the "Escrow Shares"), and any dividends or other
      distributions comprising the Additional Escrow Fund currently being held by
      the
      Escrow Agent pursuant to the Escrow Agreement by and among Cytogen and AMI
      and
      the Escrow Agent, dated as of August 25, 2000 (the “Escrow
      Agreement”).  If required by the Escrow Agent, Cytogen and AMI shall
      also execute and provide any further instructions reasonably necessary to enable
      Cytogen's Transfer Agent to reissue the Escrow Shares in the name of
      Cytogen.  AMI shall also be responsible for its share of any fees
      previously incurred by the Escrow Agent pursuant to Section 5 of the Escrow
      Agreement.  The Escrow Agreement shall terminate upon the transfer of
      the 50,000 shares of Cytogen stock to Cytogen as provided
      herein.  Notwithstanding the preceding sentence, and subject only to
      this Section 2, AMI is no longer subject to any obligations under the Escrow
      Agreement.





3.
            STIPULATION
                OF DISMISSAL.





Immediately
      following Cytogen’s receipt of the Settlement Amount, the Parties shall file
      with the Court a Stipulation of Dismissal with Prejudice in the form attached
      hereto as Exhibit A.





4.
            MUTUAL
                RELEASES.





Effective
      as of the full execution of this Settlement Agreement and payment to Cytogen
      of
      the Settlement Amount pursuant to Section 1, above, in consideration of the
      settlement of the Lawsuit and other good and valuable consideration, the receipt
      and sufficiency of which are hereby acknowledged, and subject only to the
      proviso contained in the second sentence of this





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Release,
      the Parties, on behalf of themselves and their parents, subsidiaries,
      affiliates, predecessors, successors and assigns, and all past and present
      officers, directors, employees, shareholders, agents, servants, attorneys and
      other representatives of any of the foregoing (including persons or entities
      controlling, controlled by or under common control with Cytogen or AMI), fully,
      finally, unconditionally, irrevocably and forever release and discharge each
      other, and each other’s past and present officers, directors, employees, agents,
      servants, attorneys, insurers, and other representatives (including but not
      limited to Jerome Goldstein and Michael Becker), and all heirs, executors,
      administrators, predecessors, successors, affiliates and assigns of any of
      the
      foregoing (the “Released Parties”), from any and all claims, liabilities, causes
      of action, rights of action and actions, demands, suits, proceedings, damages,
      costs, fees and expenses, and any and all claims, demands and liabilities
      whatsoever, of every name and nature, both at law and in equity, whether known
      or unknown, suspected or unsuspected (collectively, “Claims”), including,
      without limiting the generality of the foregoing, any and all Claims which
      Cytogen or AMI now has or ever had against the other, including but not limited
      to Claims arising from or relating, directly or indirectly, to any of the
      allegations contained in the Complaint and/or Counterclaims filed in the
      Lawsuit.  Notwithstanding anything to the contrary in the preceding
      sentence, nothing in this Release shall release Cytogen or AMI, or any of the
      Released Parties, for any Claim which one party may have against the other
      for
      breach of this Settlement Agreement or for any wrong or breach arising out
      of
      any act, omission or conduct which occurs after the date of this Settlement
      Agreement.





5.
            REPRESENTATION
                BY AMI.





The
      monthly reports dated September 2006, November 14, 2006, December 19, 2006,
      January 10, 2007, and February 14, 2007 delivered by AMI to Cytogen in
      accordance with the





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terms
      of
      the License Agreement accurately reflected the status of the Combidex® Project
      in all material respects as of the date of such reports.





6.
            STATUS
                OF THE PARTIES’ VARIOUS
                AGREEMENTS.





Effective
      immediately upon complete execution of this Settlement Agreement, the License
      and Marketing Agreement by and between Cytogen Corporation and Advanced
      Magnetics, Inc., dated August 25, 2000 (the “License Agreement”) and the Supply
      Agreement by and between Cytogen Corporation and Advanced Magnetics, Inc.,
      dated
      as of August 25, 2000 (the “Supply Agreement”) are hereby terminated and are no
      longer in force or effect, and Cytogen no longer has any license, supply,
      marketing, sales or other rights whatsoever to or in Combidex® or ferumoxytol
      (formerly referred to as Code 7228).  Notwithstanding the foregoing,
      Section 7 of the License Agreement and Section 7 of the Supply Agreement
      continue and survive pursuant to their terms.





7.
            PROVISION
                AND RETURN OF MATERIALS.





By
      no
      later than twenty-one (21) days following the full execution of this Settlement
      Agreement, Cytogen: (i) shall provide to AMI all market analyses or reports,
      if
      any, in Cytogen’s possession, custody, or control for or relating to Combidex®
or magnetic resonance imaging contrast agents; and (ii) shall return to AMI
      (a)
      the Agent Technology (as defined in the License Agreement), (b) the
      Manufacturing Technology (as defined in the License Agreement), if any, in
      its
      possession, and (c) Project Information (as defined in the License Agreement)
      not developed by Cytogen, or otherwise destroy such Agent Technology,
      Manufacturing Technology and Project Information, and certify in writing and
      under oath that such Agent Technology, Manufacturing Technology and Project
      Information has been destroyed.





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8.
            CONFIDENTIALITY.





The
      Parties agree not to disclose the contents of this Settlement Agreement,
      including, but not limited to, the settlement amount or any matters pertaining
      to this Agreement and the facts and circumstances of their respective claims,
      counterclaims or allegations to any third party unless such disclosure is:
      (i)
      lawfully required by any governmental agency; (ii) otherwise required to be
      disclosed by law; (iii) necessary in any legal proceeding in order to enforce
      any provisions of this Settlement Agreement or to claim damages as a result
      of
      an alleged breach of this Settlement Agreement by the other Party; (iv)
      necessary for accounting or tax purposes, or (v) made to legal, accounting
      or
      tax professionals or to any other person or entity under an obligation to
      preserve the confidentiality of such information.  To the extent
      permitted by law, each Party agrees that it will notify the other affected
      Party
      in writing within five (5) calendar days of the receipt of any subpoena, court
      order, or administrative order requiring disclosure of information subject
      to
      this nondisclosure provision.  Notwithstanding the foregoing, the
      Parties agree that they may issue the press releases in the forms attached
      hereto as Exhibit B (AMI press release) and Exhibit C (Cytogen press release),
      and any future disclosure of the specific terms set forth in such press releases
      shall not be a violation of this Section 8.





9.
            NON-DISPARAGEMENT.





The
      Parties agree and covenant to refrain from making any statements or references,
      either directly in the form of oral or written statements or indirectly, to
      any
      third party that disparages, depreciates, ridicules, deprecates, condemns,
      criticizes, or maligns Cytogen, AMI, any of Cytogen’s or AMI’s respective
      Released Parties, Combidex®, ferumoxytol, Quadramet®, ProstaScint®, Caphosol®,
      SoltamoxTM or CYT-500.  A violation of this non-disparagement
      obligation may be remedied by injunctive relief and an award of damages and
      costs.





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10.
            PURPOSE
                AND EFFECT OF SETTLEMENT.





10.01.Each
      party to this Settlement Agreement represents that this is a full, complete
      and
      mutual settlement and is predicated solely upon each party’s desire to avoid the
      further legal expense that would be entailed in any further discovery, pretrial
      motions, trial, and appellate proceedings in the Lawsuit.





10.02.The
      Parties each warrant and represent that this Settlement Agreement is the result
      of a compromise.  While this Settlement Agreement resolves the issues
      between the parties, it does not constitute an admission by any party of any
      liability whatsoever.  Neither this Settlement Agreement nor anything
      in the Settlement Agreement shall be construed to be or shall be admissible
      in
      any proceeding as evidence of liability by any of the Parties.





11.
            CONSTRUCTION
                AND AUTHORITY.





11.01.Construction
      as Contract.  It is expressly understood and agreed that the terms
      hereof are contractual and not merely recitals and that the agreement contained
      herein, the Settlement Amount and consideration to be transferred are to
      compromise disputed claims and to avoid litigation.  It is also
      expressly understood and agreed that this Settlement Agreement has been prepared
      jointly by the parties hereto.  Each Party has cooperated in the
      drafting and preparation of this Settlement Agreement.  Hence, in any
      construction to be made of this Settlement Agreement, the same shall not be
      construed against any Party on the basis that the Party was the
      drafter.  Rather, the language of this Settlement Agreement shall in
      all instances be construed as a whole, according to its fair meaning and not
      strictly for or against any of the Parties.





11.02.Warranty.  All
      parties hereto warrant that they have read this Settlement Agreement and fully
      understand it to be a compromise and settlement and release of all claims as
      described in the releases above.  Each party further warrants and
      represents that they have not





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heretofore
      assigned or transferred to any person not a party to this Settlement Agreement
      any released claim or any part or portion thereof and each shall defend,
      indemnify and hold harmless the other from or against any claim (including
      payment of attorneys’ fees and costs actually incurred whether or not litigation
      is commenced) based on or in connection with or arising out of such transfer
      made, purported or claimed.





11.03.Authority.  Each
      party hereto, and the person executing the Settlement Agreement for each party,
      warrants and represents that this Settlement Agreement is being executed by
      and
      for each of said parties by duly-authorized representatives.  This
      Settlement Agreement binds and benefits Cytogen and AMI, their successors,
      assigns, parents, subsidiaries, divisions, affiliates, and controlled companies,
      whether corporations, partnerships, trusts, joint ventures or others, and their
      past, present and future representatives, attorneys, consultants, directors,
      officers, employees, shareholders, trustees, agents and advisors.





11.04.Representation
      by Counsel.  The Parties represent and warrant that each was
      represented by an attorney employed to represent said party with respect to
      this
      Settlement Agreement and all matters covered herein; that each party hereto
      has
      been fully advised by its attorney concerning its rights with respect to the
      execution of this Settlement Agreement; and that its attorney is authorized
      and
      directed to execute all documents and to take all necessary action to effectuate
      the terms of this Settlement Agreement and terminate the Lawsuit.





12.
            RULES
                OF
                CONSTRUCTION:  ENFORCEMENT.





12.01.Headings.  The
      paragraph and section headings are for convenience only and will not be deemed
      to affect in any way the language of the provision to which they
      refer.





12.02.Governing
      Law and Choice of Forum.  This Settlement Agreement shall be
      interpreted, construed and enforced in accordance with the substantive laws
      of
      the Commonwealth of Massachusetts, without regard to its principles of conflict
      of laws.  The





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Parties
      further consent to the exclusive jurisdiction of the federal and state courts
      in
      Massachusetts with respect to the interpretation, construction or enforcement
      of
      this Settlement Agreement or anything relating thereto.  In any action
      arising under or to enforce, construe or interpret this Settlement Agreement,
      the prevailing party shall recover its reasonable costs, expenses and attorneys’
fees from the other party.





12.03.Entire
      Agreement.  This Settlement Agreement contains the entire
      understanding of the Parties relating to the matters referred to herein, and
      may
      only be amended by a written document, duly executed on behalf of the respective
      parties.  There are no understandings, agreements, representations,
      warranties, expressed or implied, not specified herein regarding this Settlement
      Agreement or the subject matter hereof.  No waiver of any of the
      provisions of this Settlement Agreement shall constitute a waiver of any other
      provision (whether or not similar), nor shall such waiver constitute a
      continuing waiver unless otherwise expressly provided.





13.
            COUNTERPARTS.





This
      Settlement Agreement may be executed in separate counterparts, each of which
      shall be considered an original but all of which shall constitute one
      agreement.





IN
      WITNESS WHEREOF, each of the Parties has caused three (3) original copies of
      this Settlement Agreement to be executed on their behalf by their duly
      authorized representative as of the day and year aforesaid.





CYTOGEN
                CORPORATION
            
            ADVANCED
                MAGNETICS, INC.By:
                /s/ Michael D. Becker
            
            By:
                /s/ Brian J. G. PerieraDuly Authorized
            
            Duly AuthorizedName: 
                Michael D. Becker
            
            Name: 
                Brian J. G. PerieraTitle:   
                President & CEO
            
            Title:   
                President & CEODate:  
                 February 15, 2007
            
            Date:   
                February 15, 2007






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