US and Australian Biotechs Collaborate to Develop New Semen-Based Non-Invasive Prostate Cancer Test; Prostate Cancer Associated Biomarker Identified by Proteome Systems Just Days Prior to Prostate Cancer Awareness Month

Business Wire, Sept 6, 2006

BOSTON -- Just days prior to Prostate Cancer Awareness Month (September 2006) a leading biotech team developing a semen-based prostate cancer test -- designed to improve on the accuracy of the prostate-specific antigen (PSA) test -- has identified a prostate cancer biomarker associated with Human Carcinoma-Antigen (HCA). When present along with HCA, the biomarker will form the basis of a new prostate cancer diagnostic test being developed by Proteome Systems.

The test will potentially cut the number of painful and intrusive biopsies that have traditionally been required to confirm the high false positive PSA results (approx 75%). The PSA test is the only test currently available to men who are now encouraged to be tested from the age of 40 years in a bid to diagnose prostate cancer and decide on treatment options.

Prostate cancer is the second most common cancer in men and the second leading cause of death in American men. Prostate cancer will be diagnosed in some 230,000 U.S. men this year, and 30,000 will die from the disease.

Scientists at Proteome Systems (ASX:PXL) (offices in Boston and Sydney), the globally recognized diagnostics development and drug discovery company made the breakthrough working with New York-based Egenix. They have identified a prostate-specific glycoprotein that is linked to HCA. A diagnostic test that detects both the glycoprotein and the HCA modification will be highly specific for diagnosing prostate cancer using semen samples.

The current test for diagnosis of prostate cancer by elevated prostate specific antigen (PSA) in blood of men middle-aged and older is estimated to be only about 30% specific and thus gives a substantial number of false-positive results. This means that elevated PSA levels don't necessarily result from prostate cancer. A normal PSA can also be misleading, with undetected prostate cancer able to grow and spread to other parts of the body. Improvement in the ability to diagnose prostate cancer would help to avoid subjecting men to the unnecessary and costly procedure of follow-up prostate biopsy. If diagnosed early, men have a 100 percent, five-year survival rate. It is also expected the test would be used to monitor the development of prostate cancer to assist in the decisions over treatment options.

HCA was discovered by Harvard Medical School and licensed by Proteome Systems' partner Egenix Inc., as a biomarker for several types of malignant tissue tumors including prostate, lung, breast and ovarian cancer. HCA is over-expressed in prostate cancer tissue but is absent or minimally present in normal or benign, enlarged prostate tissue. Correlation of HCA with prostate cancer required the identification of a prostate-specific protein carrying the cancer-specific HCA marker.

Egenix partnered with Proteome Systems because of its leadership position in the characterization of glycoproteins. This collaboration has enabled the discovery of the HCA-associated protein that is produced by the prostate and found in semen.

This newly discovered glycoprotein is a significant step in the detection of HCA in semen to be specific to prostate cancer diagnosis.

"This significant breakthrough in identifying the glycoprotein is key to the detection of Human Carcinoma Antigen (HCA) in semen specific to prostate cancer diagnosis. It is anticipated that this discovery will lead to more accurate, less invasive and timely testing of men for prostate cancer and hence improved health outcomes within an evidenced based framework," said John Ramsay, of the Prostate Cancer Foundation Australia.

About Proteome Systems

Proteome Systems Limited (ASX:PXL) is a dynamic biotechnology company which discovers and develops diagnostics and therapeutic products. The Company has extensive expertise in the discovery and development of protein and glycoprotein biomarkers with a focus on diseases for which there are large global markets and unmet need for diagnostics and drugs such as, respiratory disease, neurobiology, neurodegenerative disease, cancer and infectious diseases. PXL's scientific leadership is demonstrated by its track record in partnering with leading US and European companies, clinical groups and research institutions to collaborate on its research programmes and develop the outcomes of its research for diagnostic and therapeutic application.

Additional information about Proteome Systems can be found at www.proteomesystems.com.