Gen-Probe to initiate Phase III trial of PCA3 test in USA


The prostate cancer gene 3 or PCA3 test has been available for some time under research protocols in the USA. This means that while the test has been accessible at a cost, it has not been available as a standard commercial test (in the same way as a PSA test is). Today, however, Gen-Probe has stated that they will be initiating a Phase III clinical trial of the PCA3 test with the goal of obtaining approval from the FDA to market this test here in America. The PCA3 test is already available in Europe.

According to the company’s media release, “Eight studies presented this week at the annual meeting of the American Urological Association (AUA) suggest that Gen-Probe’s … investigational test … 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 over-treatment.”

Gen-Probe says that the clinical study is expected to begin some time between July and September 2009 and take about a year to complete. The anticipated number of enrollees is about 500 men (all of whom have will have had at least one negative prostate biopsy) at 10 or more clinical trial sites.

“We need better tools to detect significant prostate cancers earlier, to reduce unnecessary biopsies and over-treatment, and to identify which tumors are most likely to progress,” said Gerald L. Andriole, MD, who was the lead author of the recent US PLCO study on prostate cancer screening published in the New England Journal of Medicine. He is also 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.”

PCA3 is a gene that is highly over-expressed in more than 90 percent of prostate tumors, indicating that it may have significant clinical utility as a biomarker for prostate cancer. Studies to date have shown that because PCA3 is highly specific for prostate cancer, it predicts the results of repeat biopsies more accurately than traditional prostate-specific antigen (PSA) testing.

5 Responses

  1. I’ll have to look into this further but does that mean that if the PCA3 test is FDA approved then Bostwick Labs PCA3 Plus test will then gain automatic approval, or would they have to apply themselves?

  2. I don’t pretend to be an expert on patent law or on regulatory issues related to diagnostics. (Drugs I can understand, and that’s quite complicated enough, thanks.)

  3. I’m facing a dilemma where I’d prefer to have a PCA3 instead of a biopsy. I had a heart attack less than 6 months ago, had a DES stent implant. Now I’m on Plavix. My PSAs are elevated, and of course my urologist wants me to have a biopsy, and go off Plavix. With all the horror stories about Plavix rebound phenomenon, as well as folks like myself who have gone off Plavix, and then suffered another heart attack, or clot, I do not want to stop Plavix, but also feel the need to further check out what’s going on with my prostate.

  4. Dear Mr. Samm:

    I can understand your concern, but I can also share my personal experience.

    I also had a heart attack. I have a drug-eluting stent, and I am on daily Plavix. However, I have now come off Plavix several times over the past 2.5 years for 2-3 days at a time, with the full approval of my cardiologist — to have oral surgery and a tooth extraction and for a couple of other reasons. In no case was there a problem.

    I would suggest you call your cardiologist and ask him for his opinion on whether it would be OK for you to come off the Plavix for a couple of days. He is the person who is best able to give you guidance here. The PCA3 test is not a replacement for a biopsy, based on currently available data.

  5. As a follow up… My original urologist would not talk with me about my issues, and would not return phone calls… so, I googled for another urologist. I found one who was EXCELLENT. He totally understood my concerns, and said, for the moment, a biopsy would not be necessary …. He placed me on finasteride, and told me that in 6 months he wanted another PSA test. After 6 months, my PSAs are well withing limits, and my symptoms have disappeared …. It seems that there was another drug that I was taking for light depression that was contributing to my prostate problems. I’ve since stopped taking the anti-depression drug, am still on finasteride, and all is well. I still get an annual digital exam plus PSA level. I do believe that in this case, the original urologist was too “biopsy happy,” and have since found out from previous patients of his that they experienced the same thing, and have since moved on to a different urologist.

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