Expanded Role for Cytogen's PROSTASCINT(R) Incorporated Into NCCN(R) Clinical Practice Guidelines.

Revised Guidelines Now Include PROSTASCINT Imaging for Recurrent Disease

PRINCETON, N.J. -- Cytogen Corporation (NASDAQ: CYTO) today reported that the National Comprehensive Cancer Network (NCCN) has included PROSTASCINT([R]) (capromab pendetide) in its updated clinical practice guidelines for recurrent prostate cancer. PROSTASCINT is the first and only commercial monoclonal antibody-based agent that targets prostate-specific membrane antigen (PSMA) to image the extent and spread of prostate cancer. Expanded inclusion in the NCCN's guidelines further reinforces the value of PROSTASCINT for evaluation of prostate cancer in patients suspected of having locally recurrent disease.

"Proper selection of therapy depends on whether prostate cancer has spread from the prostate gland," said Michael Manyak, M.D., vice president of medical affairs. "The NCCN guidelines recognize that fused PROSTASCINT images can assist in that determination."

Emerging data from several sources using the superimposition, or fusion, of the PROSTASCINT functional study upon an anatomic image such as Computed Tomography Imaging (CT) or Magnetic Resonance Imaging (MRI), have generated renewed interest in the clinical application of these images. The expanded NCCN guidelines reflect the growing awareness of the potential for fused scans of this type to assess disease and plan individualized treatment regimens.

"The use of these fused PROSTASCINT scans has significantly benefited our patients receiving brachytherapy," explained Rodney J. Ellis, M.D., a radiation oncologist and assistant professor of urology with the Case School of Medicine. Dr. Ellis is the lead author on a long term study demonstrating a three-fold difference in biochemical disease-free survival between patients who had suggested metastatic deposits and those without on the fused images. "The expanded NCCN guidelines take into consideration these and other findings that have improved prostate cancer localization through the use of fused PROSTASCINT images."

NCCN, a non-profit alliance of 20 of the world's top cancer centers, issues Clinical Guidelines in Oncology that are a benchmark for clinical policy in the oncology community. These guidelines are updated continually and are based upon evaluation of scientific data integrated with expert judgment by multidisciplinary panels of expert physicians from NCCN member institutions. NCCN has posted the updated information to its website at http://www.nccn.org.

The NCCN guidelines are distributed free of charge to clinical professionals in the United States and internationally. User-friendly patient versions of NCCN guidelines are available to patients and their families. For more information, call the NCCN at [phone] or visit http://www.nccn.org.

About Prostate Cancer

Prostate cancer is the most common type of cancer found in American men, other than skin cancer. In 2006, the American Cancer Society estimates that there will be about 234,000 new cases of prostate cancer in the United States and that about 27,000 men will die from the disease. It is estimated that there are more than 2 million American men currently living with prostate cancer. Tests to determine the amount of prostate-specific antigen (PSA), a protein produced by the cells of the prostate gland, in the blood along with a digital rectal exam is used to help initially detect prostate cancer and is also used to monitor patients with a history of prostate cancer to see if the cancer has come back, or recurred. PSA levels cannot directly identify the extent or location of disease.

About PROSTASCINT([R])

Cytogen's PROSTASCINT molecular imaging agent is the first and only commercial product targeting prostate-specific membrane antigen or PSMA. PROSTASCINT consists of Cytogen's proprietary PSMA-targeting monoclonal antibody, 7E11-C5, linked to the imaging radioisotope Indium-111. By targeting PSMA, the PROSTASCINT molecular imaging procedure can detect the extent and spread of prostate cancer using a standard gamma camera.

PROSTASCINT is indicated as a diagnostic imaging agent in newly diagnosed patients with biopsy-proven prostate cancer, thought to be clinically localized after standard diagnostic evaluation and who are thought to be at high risk for pelvic lymph node metastases. PROSTASCINT is also indicated as a diagnostic imaging agent in post-prostatectomy patients with a rising PSA and a negative or equivocal standard metastatic evaluation in whom there is a high clinical suspicion of occult metastatic disease.

A copy of the full prescribing information for PROSTASCINT, including warnings, precautions, adverse events and other safety information, may be obtained in the U.S. from Cytogen Corporation by calling toll-free 800-833-3533 or by visiting the Web site at http://www.cytogen.com, which is not part of this press release.

About Prostate-Specific Membrane Antigen or PSMA

Prostate-specific membrane antigen or PSMA is a protein abundantly expressed on the surface of prostate cancer cells, with an increased expression in high-grade cancers, metastatic disease and hormone-refractory prostate cancer. PSMA is also present at high levels on the newly formed blood vessels, or neovasculature, needed for the growth and survival of many solid tumors. In contrast to other prostate-related antigens, such as prostate-specific antigen (PSA), prostatic acid phosphatase (PAP) and prostate secretory protein, PSMA is a membrane glycoprotein that is not secreted. These unique attributes make PSMA an excellent target for monoclonal antibody diagnostic and therapeutic options in prostate and potentially other cancers. Clinical studies have also demonstrated that overexpression of PSMA determined by immunohistochemical staining using the 7E11-C5 antibody in primary prostate cancer correlates with other adverse prognostic factors and can independently predict disease recurrence.

About Cytogen

Founded in 1980, Cytogen is a biopharmaceutical company dedicated to advancing the care of cancer patients by building, developing, and commercializing a portfolio of specialty pharmaceutical products. The Company's specialized sales force currently markets QUADRAMET([R]), PROSTASCINT([R]), and SOLTAMOX([TM]) to the U.S. oncology market. QUADRAMET is approved for the treatment of pain in patients whose cancer has spread to the bone, PROSTASCINT is 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. During the first half of 2007, Cytogen plans to introduce its fourth approved oncology product to the U.S. market, CAPHOSOL([R]), a prescription medical device for the treatment of oral mucositis and dry mouth. 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: the risk of successfully marketing PROSTASCINT; 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. All information in this press release, including 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 this information to reflect subsequent events or circumstances.