Preclinical Data on Cytogen's Technology to be Reported at the AACR Annual Meeting.

PRINCETON, N.J. -- Cytogen Corporation (NASDAQ: CYTO) today reported the upcoming presentation of preclinical data at the 2007 Annual Meeting of the American Association for Cancer Research (AACR) taking place in Los Angeles, California April 14-18, 2007. The AACR abstracts are based on preclinical studies that validate novel approaches to drug discovery and development embodied in the Company's proprietary Abtides[TM] (Antigen-Binding pepTIDES) and oral drug delivery platforms. These data represent a broad scope of findings from in vitro (cell line) and in vivo (animal) experiments.

While Cytogen's internal research and development initiatives focus on clinical-stage opportunities, the Company complements its internal programs with an active business development strategy, which includes capitalizing on the promising proprietary technology platforms previously developed through its AxCell BioSciences research-stage subsidiary. In view of recent biological validation, as well as the progress of internal data mining efforts and external research collaborations, Cytogen is exploring strategic transactions for AxCell BioSciences and will be presenting at the 9th Annual C21 BioVentures Conference (C21) taking place in Monterey, California May 22-24, 2007.

Additional details for the AACR presentations are as follows:

     Presentation Date and Time: Sunday, April 15, 2007,
                                 8:00 AM -12:00 PM
     Abstract #645: Studies with long random phage libraries:
     Epitope-specific peptides recapitulate antibody complementarity
     determining regions (CDRs) of PSMA and MUC-1 antibodies and PSMA
     binding peptides target prostate xenografts.

     Presentation Date and Time: Sunday, April 15, 2007,
                                 1:00 PM - 5:00 PM
     Abstract #1497: Oral delivery of leuprolide in a rat model using
     poly-lactide-glycolic acid (PLGA) nanoparticles coated with
     active-transport peptides derived from phage libraries.

The abstracts are available and can be viewed on-line at no charge
through the AACR website at http://www.aacr.org, which is not part of
this press release.

About Antigen-Binding peptides or Abtides[TM]

AxCell has developed Abtides; small, highly specific peptides, 38-43 amino acids in length, obtained from its novel phage libraries. Their small size, specific target recognition, high affinity and cost-efficient one-step chemical synthesis make them ideal as therapeutic and/or imaging agents and provide valuable advantages over other targeting agents, such as monoclonal antibodies. AxCell has already produced Abtides that target prostate-specific membrane antigen (PSMA) on prostate cancer cells and MUC-1, a tumor antigen expressed in breast, pancreatic and ovarian cancers. Other Abtides with specificity for EGFR-positive tumors are also being investigated.

About Oral Drug Delivery Technology

AxCell has also developed oral drug delivery agents - random peptide compositions that bind to gastro-intestinal tract (GIT) transporter proteins. These oral delivery agents are capable of facilitating transport of an active agent from the lumenal side of the GIT into the systemic blood system, and/or in targeting active agents to the GIT. By binding (covalently or noncovalently) these oral delivery agents to a drug or by coating the surface of nanoparticles or liposomes with these delivery agents, drugs can be targeted to specific receptor sites or transport pathways known to operate in the human gastrointestinal tract, thus facilitating its systemic absorption into the bloodstream. The binding of these oral delivery agents to GIT receptors has been confirmed in preclinical models, and successful in vivo delivery of nanoparticle-encapsulated insulin and leuprolide in animal models has been demonstrated.

About Cytogen

Cytogen is a specialty pharmaceutical company dedicated to advancing the treatment and care of cancer patients by building, developing, and commercializing a portfolio of oncology products. The Company's specialized sales force currently markets CAPHOSOL([R]), QUADRAMET([R]), PROSTASCINT([R]), and SOLTAMOX([TM]) to the U.S. oncology market. CAPHOSOL is an advanced electrolyte solution for the treatment of oral mucositis and dry mouth that was approved as a prescription medical device. QUADRAMET is approved for the treatment of pain in patients whose cancer has spread to the bone. PROSTASCINTis a PSMA-targeting monoclonal antibody-based agent to image the extent and spread of prostate cancer and SOLTAMOX is the first liquid hormonal therapy approved in the U.S. for the treatment of breast cancer in adjuvant and metastatic settings. The Company is also developing CYT-500, a third-generation radiolabeled antibody to treat prostate cancer. Cytogen's product-focused strategy focuses on attaining sustainable growth through clinical, commercial, and strategic initiatives.

A copy of the full prescribing information for CAPHOSOL, QUADRAMET, PROSTASCINT, and SOLTAMOX, including box warnings, may be obtained in the U.S. from Cytogen Corporation by calling toll free 800-833-3533 or by visiting Cytogen's web site at www.cytogen.com. The Company's website 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 Cytogen's ability to successfully execute strategic transactions for its technology platforms, 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 statements contained herein are made only as of the date of this press release, and Cytogen undertakes no obligation to publicly update this information to reflect subsequent events or circumstances.