PRINCETON, N.J., May 24 /PRNewswire-FirstCall/ -- Cytogen Corporation today announced the presentation of seven-year outcomes data relating to PROSTASCINT(R) (capromab pendetide), 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 results were presented today during the 101st American Urological Association Annual Meeting held in Atlanta, GA.
“About 85% of all prostate cancer cases diagnosed are clinically localized and treated with radical prostatectomy or radiation therapy,” said Rodney J. Ellis, M.D., radiation oncologist at Aultman Hospital, assistant professor urology with CASE School of Medicine, associate professor radiology with Northeastern Ohio University, and one of the authors of the study. “Managing these patients is complicated because it is difficult to accurately predict which patients are at high or low risk for developing prostate cancer recurrence following therapy. Based on our study results, PROSTASCINT may help provide insight into this often problematic clinical situation on a patient-specific basis.”
The study evaluated the use of fusion imaging with PROSTASCINT to assess disease in 239 newly diagnosed prostate cancer patients prior to undergoing brachytherapy with either iodine-125 or palladium-103 radioactive seed implants. Brachytherapy, an outpatient procedure used in the treatment of different kinds of cancer, consists of radioactive “seeds” that are carefully placed inside of the cancerous tissue and positioned in a manner that will attack the cancer most efficiently. The radioactive seeds are about the size of a grain of rice, and give off radiation that travels only a few millimeters to kill nearby cancer cells.
Fusion imaging with PROSTASCINT, or hybrid imaging, is an in vivo diagnostic technique that combines anatomic images with functional images. Anatomical information derived from either computed tomography (CT) or magnetic resonance (MR) imaging can be fused (or co-registered) with functional information obtained using single-photon emission computed tomography (SPECT) and novel molecular imaging agents, such as PROSTASCINT. SPECT imaging focuses on metabolic abnormalities that may be present earlier than the anatomical changes otherwise seen with CT or MR imaging alone. Co- registering anatomic and functional images provides an anatomic context for areas of enhanced or abnormal uptake, helping physicians identify areas of disease and enabling them to better plan an individualized treatment protocol for patients.
Seven-year outcomes for patients in the study were evaluated based on American Society for Therapeutic Radiology and Oncology (ASTRO) consensus criteria as well as more stringent criteria involving prostate-specific antigen (PSA) cut-offs of 1.0 ng/mL and 0.5 ng/mL. For the entire group (217 patients with local disease, 22 patients with extraprostatic disease), biochemical disease free survival (bDFS) at seven years for patients in whom the PROSTASCINT scan showed disease confined to the prostate as opposed to those who had uptake outside the peri-prostatic region (including uptake in lymph nodes) was 91% vs. 66% by the ASTRO criteria (p=0.0003), 87% vs. 46% by the PSA <1.0 criteria (p<0.0001) and 86% vs. 44% by the PSA <0.5 criteria (p<0.0001). For the hormonal naive sub-population (171 localized, 18 extraprostatic), the seven-year bDFS was 92% vs. 64% (p=0.0004), 88% vs. 31% (p<0.0001), and 87% vs. 30% (p<0.0001) with the same criteria. Hazard ratios for patients with PROSTASCINT uptake outside the prostate were 3-fold higher for the entire group and four-fold higher for the hormonal naive subgroup. These differences were noted across all risk categories, particularly for those patients with intermediate and high risk features associated with their cancer.
“This data presented at the AUA meeting adds to the growing body of peer reviewed clinical literature and presentations at major medical meetings reporting the clinical utility and positive outcomes associated with fusion imaging with PROSTASCINT,” commented Michael D. Becker, president and chief executive officer of Cytogen.
A copy of the following abstract presented at the AUA annual meeting is currently available on the AUA website at http://www.auanet.org, which is not part of this press release:
“SPECT/CT Capromab Pendetide Independently Predicts bDFS in Long Term Outcome Study” presented on Wednesday, May 24 from 1:00 p.m. to 3:00 p.m. during a Podium Session on Prostate Cancer: Staging (II) (Abstract # 1649).
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
Cytogen’s PROSTASCINT molecular imaging agent is the first and only commercial product targeting PSMA. PROSTASCINT consists of a monoclonal antibody (7E11.C5.3) directed against PSMA that is 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.
Cytogen is also developing CYT-500, a therapeutic product candidate using the same monoclonal antibody from PROSTASCINT combined with a higher affinity linker to attach a therapeutic as opposed to an imaging radionuclide. CYT-500 is designed to enable targeted delivery of a cytotoxic agent to PSMA- expressing cells. Cytogen expects to begin the first U.S. Phase I clinical trial of CYT-500 in patients with hormone-refractory prostate cancer during 2006.
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 PSMA
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.C5.3 antibody in primary prostate cancer not only correlates with other adverse traditional prognostic factors, but can independently predict disease recurrence.
ABOUT CYTOGEN CORPORATION
Founded in 1980, Cytogen Corporation of Princeton, NJ, is a biopharmaceutical company dedicated to improving the lives of patients with cancer by acquiring, developing and commercializing innovative molecules targeting the sites and stages of cancer progression. Cytogen’s marketed products include QUADRAMET(R) (samarium Sm-153 lexidronam injection), PROSTASCINT(R) (capromab pendetide) kit for the preparation of Indium In-111 capromab pendetide, and SOLTAMOX(TM) (tamoxifen citrate, oral solution 10mg/5mL) in the United States. Cytogen’s development pipeline consists of CYT-500, a therapeutic radiolabeled antibody targeting prostate-specific membrane antigen (PSMA), a protein highly expressed on the surface of prostate cancer cells and the neovasculature of solid tumors. 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. Full prescribing information for the Company’s products is available at http://www.cytogen.com or by calling 800-833-3533. For more information, please visit the Company’s website at http://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 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.
Cytogen Corporation
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