By Turna Ray
Myriad Genetics this week launched Prolaris, a multi-gene prognostic test for prostate cancer that it said is the first diagnostic test to gauge prostate cancer recurrence.
Prolaris is a 46-gene prognostic test that quantitatively determines the risk of prostate cancer recurrence in patients who have undergone a prostatectomy. "For the first time, physicians now have a direct molecular measure of a prostate tumor's capacity to divide and grow by examining the mechanics of growth at the molecular level," the company said.
The company is planning to market the test, which has a $3,400 price tag, to urologists as a more accurate tool for gauging prostate cancer recurrence risk in their patients. The test will be marketed by Myriad's existing 300-person sales team, and the company is also building a specialty sales team that will reach out specifically to urologists.
By measuring expression levels of multiple genes related to cell cycle progression, Prolaris can identify patients at low risk of disease with 95 percent certainty, which could keep them from having to endure adverse reactions associated with unnecessary, aggressive treatments, Myriad claimed.
"Conversely, men with high Prolaris scores would be considered for more intensive screening and adjuvant therapy to address their more aggressive disease," Myriad said.
In one completed study of 365 prostate cancer patients, 98.5 percent of patients with a low Prolaris score survived their disease after a decade. In comparison, 57.6 percent of patients in the study with a high score died of prostate cancer within the same time frame.
Myriad plans to present data from a clinical validation study involving Prolaris at the 2010 Genitourinary Cancers Symposium, scheduled for March 5-7 in San Francisco. The abstract, entitled "Cell Cycle Genes Predict Recurrence After Radical Prostatectomy," will be presented at the conference by Gregory Swanson and colleagues and released on the American Society of Clinical Oncology's website March 3.
"We view Prolaris as the first of a strong emerging stable of RNA signature tools based on fundamental tumor biology [that] Myriad will offer to the urology/oncology community," Myriad Genetic Laboratories President Mark Capone said in a statement.
Prolaris is the first of two molecular tests that Myriad has slated for launch this year. The company plans to release a genetic predictive test for pancreatic cancer in the Fall.
In the US, it is estimated that approximately 192,000 men are diagnosed with prostate cancer annually. Of these men, 80,000 will undergo a radical prostatectomy, but 35 percent of those men will experience cancer recurrence despite the surgery.
"Current models based on clinical variables cannot effectively predict in which of these men the disease will recur," Myriad said in a statement. The company is hoping to improve doctors' ability to predict recurrence in this subset of patients with the availability of its molecular diagnostic test.
Myriad's test launch comes just as the American Cancer Society has updated guidelines for prostate cancer this week. The new ACS guidelines recommend that doctors need to be "more heavily involved" in their patients' decision to get screened for prostate cancer, due to conflicting study results that confound the benefit of screening on preventing deaths from prostate cancer.
With regard to genetic testing, the new guidelines point out that "prostate cancer seems to run in some families, which suggests that in some cases there may be an inherited or genetic factor."
Additionally, the guidelines note that although some common gene variations have been linked to the risk of prostate cancer, "studies to confirm these results are needed to see if testing for the gene variants will be useful in predicting prostate cancer risk."
Peter Carroll, deputy director at the Yale Cancer Center, said during a Myriad investor update this week that the biomarkers in the 46-gene test could be "game changing" in terms of how prostate cancer recurrence is managed in the US, particularly with regard to improving physicians' ability to differentiate between indolent and progressive prostate cancers.
In Carroll's view, Prolaris could potentially help reduce overtreatment of prostate cancer in this country. If ongoing studies validate the utility of the test, Carroll said he would recommend the test to patients presenting to the University of Texas' Cancer Therapy & Research Center.
Prolaris is the eighth test in Myriad Genetics' portfolio, which also houses the flagship product BRACAnalysis, Colaris, Colaris AP, Melaris, TheraGuide, Prezeon, and OnDose.