Northwestern University Study Finds Ultrasensitive Assay Can Predict Recurrence of Prostate Cancer

NORTHBROOK, Ill., Oct. 19, 2009 (GLOBE NEWSWIRE) -- Nanosphere, Inc. NSPH, a leader in the development and commercialization of advanced molecular diagnostics systems, today announced that a research team at Northwestern University's International Institute for Nanotechnology found that an ultrasensitive nanoparticle-based assay, 300 times more sensitive than commercial immunoassays, is capable of detecting previously undetectable levels of prostate-specific antigen (PSA) in patients who have undergone radical prostatectomy.

After the removal of the prostate gland, patients typically have PSA levels that are undetectable when measured by using conventional diagnostic tools, and which can take years to detect recurrent cancer. This ability to easily and quickly detect very low levels of PSA may enable doctors to diagnose men with prostate cancer recurrence years earlier than is currently possible. Prostate cancer is the second leading cause of cancer death for men in the United States. (Only lung cancer is more deadly.)

"We have defined a new zero for PSA," said Chad A. Mirkin, George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, professor of medicine and professor of materials science and engineering and a director of Nanosphere. "This level of sensitivity in detecting low concentrations of PSA will take the blinders off the medical community, especially when it comes to tracking residual disease."

The clinical pilot study, led by Dr. Chad Mirkin and C. Shad Thaxton, M.D., assistant professor of urology in Northwestern's Feinberg School of Medicine, was designed to assess the ability of Nanosphere's nanoparticle-based bio-barcode assay probe to detect PSA levels in the serum of 18 men who had undergone radical prostatectomy for prostate cancer. (Dr. Mirkin and Dr. Thaxton are members of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.) The study will be published today in the Proceedings of the National Academy of Sciences (PNAS), the Academy's scientific journal.

"This study validates the enormous capabilities of our nanoparticle-based assays and the Verigene platform which has been developed by Nanosphere scientists and engineers," said William Moffitt, Nanosphere's president and chief executive officer. "This ultrasensitive assay for testing PSA levels points to several significant outcomes that can have tremendous impact on how men with post radical prostatectomies are treated. For those patients with detectable and non-rising PSA levels, which is 42% of the population who have undergone radical prostatectomies, they can be informed much sooner that their cancer will not recur, relieving them of additional treatment and emotional burden."

"For the remaining patients the Nanosphere ultrasensitive assay will be able to assign recurrence much earlier than conventional assays. These men can be treated at a much earlier stage, and possibly enhancing their ultimate outcomes," Mr. Moffitt explained. "The third significant possible outcome from this study is the confirmation that PSA levels can now be detected in this radical prostatectomy population which validates PSA as a definitive marker for follow-on experimental therapies that can be used in treatment for recurrence of the cancer."

Nanosphere and Northwestern's International Institute for Nanotechnology are currently engaged in a retrospective study on radical prostatectomy patients and will soon be launching a broad prospective study.

About Nanosphere, Inc.

Nanosphere develops, manufactures and markets an advanced molecular diagnostics platform, the Verigene(R) System, for direct genomic and ultra-sensitive protein detection. This easy to use and cost effective platform enables simple, low cost and highly sensitive genomic and protein testing on a single platform. Nanosphere is based in Northbrook, IL. Additional information is available at http://www.nanosphere.us.

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