Outcomes Data Demonstrating Prognostic Value of Cytogen's PROSTASCINT Published in Peer-Reviewed Journal Urology.

PRINCETON, N.J. -- Cytogen Corporation (NASDAQ: CYTO) today reported the publication of data from a large cohort study demonstrating the value of PROSTASCINT([R]) (capromab pendetide) in predicting outcomes for patients with prostate cancer. The study evaluated patients whose PROSTASCINT images showed a localization pattern known as central abdomen uptake (CAU), a finding suggestive of metastatic disease, as compared to those without such findings. In the study, prostate cancer-specific death rates were 10 times higher in patients with CAU than in patients without CAU (p=0.005).

These findings reinforce that PROSTASCINT imaging provides information that can aid clinicians in defining patients whose specific disease characteristics warrant more careful monitoring or aggressive treatment. 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.

The study, "Central Abdominal Uptake of In-111 Capromab Pendetide (ProstaScint) Predicts Poor Prognosis in Patients with Prostate Cancer," by Haseman, et al., appears in the current issue of the peer-reviewed journal, Urology (Urology 70: 303-308, 2007.) In May 2007, investigators presented portions of this data at the Annual Meeting of the American Urological Association.

Investigators reviewed records of 341 men with prostate cancer who underwent PROSTASCINT imaging between 1994 and 1999 with a median follow-up period of 4.1 years. Patients were divided into two groups based on whether CAU was present or absent. CAU was detected in 69 (20%) patients. Five of the 69 CAU-positive patients (7.2%) died of prostate cancer-specific death, compared to two of the 272 (0.7%) CAU-negative patients (p=0.005). This ten-fold increase in prostate cancer-specific death rates was independent of the use or timing of intervention with hormone therapy. These outcomes data reinforce that patients with CAU should be considered for systemic therapy and may be excellent candidates for clinical trials.

"For physicians involved in the care of patients with prostate cancer there remains a significant unmet need for methods of identifying those patients most likely to benefit from earlier and more aggressive intervention as opposed to those who can be managed using more conservative strategies," commented Michael J. Manyak, MD, Vice President of Medical Affairs for Cytogen Corporation and a co-author of the publication. "These newly published data demonstrate that ProstaScint imaging can play an important role in assisting physicians and patients in making such decisions."

About Prostate Cancer

Prostate cancer is the most common type of cancer found in American men, other than skin cancer. In 2007, the American Cancer Society estimates that there will be about 219,000 new cases of prostate cancer in the United States and that about 27,000 men will die from the disease. It is estimated that more than 2 million American men are 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 are used to help initially detect prostate cancer and also 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

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.

Emerging data from several sources using the superimposition, or fusion, of the PROSTASCINT functional study upon an anatomic image such as Computed Tomography (CT) Imaging or Magnetic Resonance Imaging (MRI), have generated renewed interest in the clinical value of PROSTASCINT imaging. In January 2007, the National Comprehensive Cancer Network, or NCCN, updated its clinical practice guidelines and expanded PROSTASCINT's role to include recurrent disease. The expanded NCCN guidelines reflect the growing awareness of the potential for PROSTASCINT fusion imaging to assess disease and plan individualized treatment regimens.

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.

This press release discusses clinical applications that differ from those reported in the PROSTASCINT package insert.

About Cytogen

Cytogen is a specialty pharmaceutical company dedicated to advancing the treatment and care of patients by building, developing, and commercializing a portfolio of oncology products. The Company's specialized sales force currently markets three therapeutic products and one diagnostic product to the U.S. oncology market. CAPHOSOL[R] is an advanced electrolyte solution for the treatment of oral mucositis and dry mouth that is approved in the U.S. as a prescription medical device. QUADRAMET[R] (samarium Sm-153 lexidronam injection) is approved for the treatment of pain in patients whose cancer has spread to the bone. PROSTASCINT[R] (capromab pendetide) is a PSMA-targeting monoclonal antibody-based agent to image the extent and spread of prostate cancer and SOLTAMOX[TM] (tamoxifen citrate) 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 centers on attaining sustainable growth through clinical, commercial, and strategic initiatives.

A copy of the full prescribing information for CAPHOSOL, QUADRAMET, PROSTASCINT and SOLTAMOX, including Boxed Warnings, 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. Cytogen's website is not part of this press release.

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