Proteome Systems Makes Breakthrough in Development of Semen-Based Prostate Cancer Test; Discovery of Prostate-Specific Biomarker Protein Enables Improved Specificity of Diagnosing Prostate Cancer Using Semen Samples

Business Wire, August 1, 2006

BOSTON & SYDNEY, Australia -- Scientists at Proteome Systems (ASX:PXL), the globally recognized diagnostics development and drug discovery company, have made an important breakthrough in their quest for developing a new diagnostic test for prostate cancer. They have identified a prostate-specific glycoprotein that is linked to Human Carcinoma Antigen (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.

Prostate Cancer is the second most common cancer in men and the second leading cause of death in American men (It is estimated that prostate cancer will be diagnosed in some 230,000 men this year, and 30,000 will die from it in the United States alone).

"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.

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