ExoDx Prostate Non-Invasive Test May Eliminate Unnecessary Prostate Biopsies, Study Says

ExoDx Prostate Non-Invasive Test May Eliminate Unnecessary Prostate Biopsies, Study Says

Exosome Diagnostics revealed positive clinical results evaluating its urine-based prostate cancer liquid biopsy test called ExoDx Prostate (IntelliScore).

The study, “A Novel Urine Exosome Gene Expression Assay to Predict High-grade Prostate Cancer at Initial Biopsy,” published in JAMA Oncology, indicates the novel test could eliminate the need for tissue biopsies, supporting the value of investing in research targeting Exosomal RNA for diagnostic and patient screening applications.

Exosome, who first presented the results at the 2015 American Urological Association (AUA) Annual Meeting, plans to launch the RNA-based test in the second quarter of 2016.

In most developed countries, there is a tendency for overdiagnosis and overtreatment of low-grade (indolent) prostate cancer, which has become a significant health issue. Prostate-Specific Antigen (PSA) testing has low specificity, often resulting in false negative and false positive results and not distinguishing between high-grade and low-grade cancer, which usually does not require aggressive treatment. As such, there is a need for noninvasive, easy to administer, diagnostic assays to help assess if invasive biopsies are indeed necessary. In fact, over 75 percent of prostate biopsies end up being either benign or from low-grade cancers.

Exome diagnostics developed the ExoDx Prostate (IntelliScore), a clinically validated, non-digital rectal exam urine-based liquid biopsy test that predicts the presence of high-grade (Gleason score of 7 or greater) prostate cancer for men age 50 and older with a PSA 2 to 10 mg/mL presenting for an initial biopsy.

The test analyzes urine samples for three biomarkers on exosomal RNA (exoRNA) that are known to be expressed by men with high-grade prostate cancer. Using an algorithm, the test assigns an individual risk score, which can be used with other standard prognostic tools to assess the need for a tissue biopsy.

In their study, researchers wanted to assess the performance of a novel urine exosome gene expression assay in addition to standard of care (SOC) (PSA level, age, race, and family history) vs SOC alone for discriminating between Gleason score 7 and 6 and benign disease. According to results from samples of 499 patients, in 255 of the patients the urine exosome gene expression assay plus SOC was associated with improved discrimination between GS7 or greater and GS6 and benign disease.

“The possibility of a ‘liquid biopsy’ that does not involve an invasive procedure and may be as simple as a urine test has the potential to change the way we approach the most common cancer in men. If the predictive accuracy of the assay can be validated in further studies, it has the potential to replace the PSA test once and for all,” lead author and principal investigator James McKiernan, M.D., said in a news release.