Outcomes Data Continue to Demonstrate Value of Cytogen's PROSTASCINT(R) to Predict Prognosis in Prostate Cancer.

PRINCETON, N.J. -- Cytogen Corporation (NASDAQ: CYTO) today reported outcomes data from a large cohort study demonstrating the value of PROSTASCINT([R]) (capromab pendetide) in predicting prognosis in prostate cancer.(i) The study evaluated the outcomes of patients whose PROSTASCINT images showed uptake in the central abdomen, 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 central abdominal uptake (CAU) than in patients without CAU (p=0.005).(i) These results further reinforce that PROSTASCINT offers a level of accuracy and detail to prostate cancer imaging that can aid clinicians in defining patients' prognoses and treatment regimens.

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, "Capromab pendetide (ProstaScint) imaging with central abdominal uptake: poor outcomes for prostate cancer patients," by Haseman, et al., was presented at the 2007 Annual Meeting of the American Urological Association taking place May 19-24, 2007 in Anaheim, California.

"As the only functional imaging agent available for prostate cancer, PROSTASCINT brings greater clarity to prostate cancer imaging, enabling more precise assessment of disease," commented Michael J. Manyak, M.D., vice president of medical affairs with Cytogen. "The poor outcomes among men whose PROSTASCINT scan detected central abdominal activity support what has long been suspected -- that the detection of central abdominal activity on PROSTASCINT scans is indicative of metastatic activity. Following the presentation of eight-year outcomes data in February 2007, this outcomes study further demonstrates PROSTASCINT's utility for prognosis. The data presented here today reinforce the value of information obtained from PROSTASCINT scans to assist in selection of appropriate therapy."

The investigators reviewed records of 341 men with prostate cancer who underwent PROSTASCINT imaging between 1994 and 1999 and were followed up for a median of 4.1 years.(i) Patients were divided into two groups based on whether CAU was present or absent.(i) CAU was detected in 69 (20%) patients. Of the 262 men who received pelvic radiotherapy after the PROSCASCINT scan, 57 (83%) had evidence of CAU and 205 (75%) did not (p=0.2). Five of the 69 patients (7.2%) in the CAU group died of prostate cancer, compared to two of the 272 (0.7%) CAU-negative patients (p=0.005).(i) The ten-fold increase in prostate cancer-specific death rates was independent of the use or timing of intervention with hormone therapy. These outcomes data confirm that high signal intensity in the abdomen is a negative prognostic sign.

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.(ii) It is estimated that more than 2 million American men are currently living with prostate cancer.(iii) 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. 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.

(i) Manyak MJ, Rosenthal SA, Haseman MK, Kipper SL, Trout JR. Capromab pendetide (ProstaScint) imaging with central abdominal uptake: poor outcomes for prostate cancer patients. Presented at the American Urological Association Annual Meeting, Anaheim, Calif., May 19-24, 2007 (abstract 1018). (lines 23-24)

(ii) American Cancer Society. How Many Men Get Prostate Cancer? May 2006. Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_2_1X_ How_many_men_get_prostate_cancer_36.asp?sitearea=. Accessed April 2007.

(iii) National Cancer Institute. SEER Cancer Statistics Review 1975-2003, Table I-17. September 2005. Available at: http://seer.cancer.gov/csr/1975_2003/results_single/sect_01_table. 17_2pgs.pdf. Accessed April 2007.

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