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MEDIA/INVESTORS CONTACT:
Jonathan Fassberg
The Trout Group
(212) 477-9007 x16

    CYTOGEN FILES BREACH OF CONTRACT LAWSUIT AGAINST ADVANCED MAGNETICS, INC.


PRINCETON,  N.J.,  (JANUARY  25,  2006) -- Cytogen  Corporation  (NASDAQ:  CYTO)
announced today that it has filed a lawsuit  against  Advanced  Magnetics,  Inc.
(AMEX: AVM) for breach of contract, fraud, unjust enrichment,  and breach of the
implied  covenant of good faith and fair  dealing.  The lawsuit,  filed today in
Massachusetts  Superior  Court,  is in  connection  with the  license  agreement
established between Cytogen and Advanced Magnetics in 2000, as amended, for both
Combidex(R) and ferumoxytol, previously Code 7228.

The  complaint  seeks  damages  along with a request  for  specific  performance
requiring Advanced Magnetics to take all reasonable steps to secure FDA approval
of Combidex in compliance with the terms of the licensing agreement. Combidex is
an investigational  functional  molecular imaging agent consisting of iron oxide
nanoparticles for use in conjunction with magnetic resonance imaging, or MRI, to
aid in the differentiation of cancerous from non-cancerous lymph nodes.

Cytogen stated that it remains  interested in discussing with Advanced Magnetics
an amicable  resolution of Cytogen's  complaints.  However,  Cytogen  intends to
protect its rights whether through litigation or negotiation.

ABOUT CYTOGEN CORPORATION
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Founded in 1980,  Cytogen  Corporation of Princeton,  NJ is a  biopharmaceutical
company  that  acquires,   develops  and  commercializes   innovative  molecules
targeting  the  sites  and  stages of  cancer  progression.  Cytogen's  marketed
products  include  QUADRAMET(R)   (samarium  Sm-153  lexidronam  injection)  and
PROSTASCINT(R)  (capromab  pendetide)  kit for the  preparation of Indium In-111
capromab  pendetide  in the United  States.  Cytogen also has  exclusive  United
States marketing rights to Combidex(R)  (ferumoxtran-10)  for all  applications,
and the exclusive right to market and sell  ferumoxytol  (previously  Code 7228)
for oncology  applications in the United States.  Cytogen's development pipeline
consists of therapeutics targeting  prostate-specific membrane antigen (PSMA), a
protein  highly  expressed  on the  surface  of  prostate  cancer  cells and the
neovasculature of solid tumors.  Full prescribing  information for the Company's
products is available at  www.cytogen.com or by calling  800-833-3533.  For more
information, please visit the Company's website at www.cytogen.com, which is not
part of this press release.

This press release  contains  certain  "forward-looking"  statements  within the
meaning of the Private Securities  Litigation Reform Act of 1995 and Section 21E
of the Securities Exchange Act of 1934, as amended.  All statements,  other than
statements of  historical  facts,  included in this press release  regarding our
strategy,  future operations,  financial  position,  future revenues,  projected
costs,  prospects,  plans  and  objectives  of  management  are  forward-looking
statements.  Such  forward-looking  statements  involve  a number  of risks  and
uncertainties  and investors are cautioned not to put any undue  reliance on any
forward-looking  statement.  There are a number of important  factors that could
cause  Cytogen's  results  to differ  materially  from those  indicated  by such
forward-looking  statements.  In particular,  Cytogen's business is subject to a
number of significant risks, which include,  but are not limited to: the risk of
successfully pursuing the Advanced Magnetics  litigation;  the risk of obtaining
additional capital;  the risk of obtaining the necessary  regulatory  approvals;
the risk of whether  products result from  development  activities;  the risk of
shifts in the regulatory  environment affecting sales of Cytogen's products such
as third-party payor  reimbursement  issues;  the risk associated with Cytogen's
dependence on its partners for development of certain projects, as well as other
factors  expressed  from time to time in  Cytogen's  periodic  filings  with the
Securities and Exchange  Commission (the "SEC"). As a result, this




press release should be read in conjunction with Cytogen's periodic filings with
the SEC. The forward-looking statements contained herein are made only as of the
date of this press  release,  and Cytogen  undertakes  no obligation to publicly
update  such   forward-looking   statements  to  reflect  subsequent  events  or
circumstances.

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