Investigational Genetic Test May Help Address Common Problems in Prostate Cancer Diagnosis

Written by Medical Letter on the CDC & FDA

2009 MAY 17 - Eight studies presented this week at the annual meeting of the American Urological Association (AUA) suggest that Gen-Probe's (NASDAQ:GPRO) investigational test for the highly specific prostate cancer gene PCA3 may help address some of the well-known challenges that urologists face when diagnosing prostate cancer, such as accurately identifying potentially aggressive cancers while minimizing "false positive" results that can lead to overtreatment.

In response to these studies and other promising data from approximately 17 peer-reviewed publications, Gen-Probe has decided to initiate a pivotal clinical study of its investigational PCA3 assay that could lead to regulatory approval by the U.S. Food and Drug Administration (FDA).

"Based on the results of our extensive clinical research studies and our European commercial experience, we believe that our PCA3 assay, when used in conjunction with other tests, can help predict the risk of a positive follow-up biopsy, thereby aiding in the diagnosis of prostate cancer," said Henry L. Nordhoff, Gen-Probe's chairman and chief executive officer. "We are pleased to be moving ahead with a U.S. clinical trial that could lead to improved patient care."

Gen-Probe's clinical study is expected to begin in the third quarter of 2009 and take about a year to complete. The Company anticipates it will involve more than 500 men, all of whom have had a negative prostate biopsy, at 10 or more clinical trial sites.

Scientific studies presented in recent weeks have added to the uncertainties surrounding prostate cancer screening and diagnosis. For example, researchers from the U.S. National Cancer Institute recently published results in the New England Journal of Medicine (NEJM) from a 17-year study that showed that six annual screenings for prostate cancer led to more diagnoses of the disease, but no fewer prostate cancer deaths.

"We need better tools to detect significant prostate cancers earlier, to reduce unnecessary biopsies and overtreatment, and to identify which tumors are most likely to progress," said Gerald L. Andriole, MD, lead author of the NEJM paper and professor and chief of urologic surgery at the Washington University School of Medicine in St. Louis. "Early data on the investigational PCA3 genetic test are promising, and we look forward to additional studies to confirm its clinical utility."