All posts by Darren K

Focused Prostate Cancer Drugs: Sophiris Bio and Steba Biotech

In the last decade, focal treatments for prostate cancer and BPH have appeared as an alternative to major prostate removal surgery.  Many of these use a minimally invasive surgical technique to ablate portions of the prostate.  These may use cryo (cold), laser (heat), HIFU (heat/ultrasound), NanoKnife (electrical) or radio frequency (heat) techniques to kill localized tumors and surrounding tissue.  Some of these techniques are already approved in the United States, while others are available in Europe, Mexico or other countries.

In the last few years, companies have also developed focused drug delivery systems to treat BPH and/or Prostate Cancer.  These include  PRX302 from Sophiris Bio and TOOKAD from Steba Biotech.

PRX302 (Topsalysin) has already completed a Phase III trial in the USA for treating BPH, or Benign Prostatic Hyperplasia (prostate enlargement).  It recently competed a Phase IIa trial for treating localized PCa, or Prostate Cancer.  It has just started a Phase IIb trial in the USA for PCa.  Topsalysin is injected into the prostate to minimize affects on other areas of the body.  It is activated by PSA, made only by prostate cells.  Once activated, it causes death of affected prostate and prostate cancer cells.  Sophiris Bio is based in Canada and trades on the NASDAQ as SPHS.

 

TOOKAD® (Padeliporfin) is also injected directly into the prostate in low risk, localized prostate cancer patients.  It recently completed Phase III trials in Europe and in Latin America and is now available in Mexico.  Once injected, near-infrared light is applied to the tumor, activating the drug and releasing toxins that destroy surrounding blood vessels and cancerous cells.  Steba Biotech is based in Luxembourg, France and Israel and is privately owned.

 

The traditional treatment for prostate cancer, radical prostatectomy, removes the entire prostate along with a section of the urethra and the internal sphincter that is used in the process of urination and ejaculation.  Obviously, this kind of major surgery has possible side effects involving sexual function, urinary continence, infection and even damage to the rectum.  Localized focal treatments generally reduce or avoid these risks and may even be performed on an outpatient basis.  The disadvantage is that they may not offer as high of a cure rate for the cancer, since some of the prostate may be left intact .  Fortunately, many of these focal treatments can be repeated or followed by a radical prostatectomy, if necessary.

Focal Prostate Cancer Therapy

Many prostate cancer patients undergo a prostate removal, or radical prostatectomy, either by conventional surgery or using the robotic da Vinci system.  What doctors may not tell you is that either method not only removes the prostate gland, but an entire section of the urethra, including one of the valves important to maintaining continence and sexual function.   This “internal sphincter” is important not only for urination, but also for ejaculation .  Complete removal and resection of the prostate and urethra is a somewhat draconian response to what is usually a tiny tumor in once small section of the prostate.

Of course, the problem is that it is difficult to locate exactly where the tumor is, if there is more than one tumor, or if it has started to spread, so many doctors simply suggest a complete removal.  Prostate Biopsies suffer from false negatives and are as controversial as complete removal of the prostate.  A radical prostatectomy is not unlike completely removing the breast in a mastectomy for a small tumor where a lumpectomy might be an alternative.

Fortunately, there are now some methods that focus on removing just the tumor, rather than the entire prostate along with a section of the urethra and the internal sphincter that helps with urination and ejaculation.  Patients should be informed about all these options.  From the highly regarded Sloan Kettering Cancer Center, these include:

  1. Focal Cryoablation (Cold treatment)
  2. HIFU (High Intensity Focused Ultrasound) (Heat treatment)
  3. NanoKnife (Electrical Treatment)
  4. Vascular Targeted Therapy (Drug treatment)
  5. MRI Guided Laser Ablation (Laser/Heat Treatment)
  6. Radiofrequency Ablation (RF/Heat Treatment)

Less than 10 years ago, these focused therapies were not even available to patients in the United States.  Some are now FDA approved, while others are undergoing trials or are available in Europe, Mexico and other countries.   These treatments are often guided by high resolution MRI, ultrasound or by targeted biopsy results.

Unlike radical prostatectomy and radiation treatments, these far less invasive therapies tend to have a lower incidence of major side effects.  On the downside, while still preliminary, their cure rates also tend to be lower.  Fortunately, unlike some radiation treatments, in many cases focal treatments can be followed by radical prostatectomy, if necessary.

Ultimately, these focal treatments tend to be for early and/or low-risk prostate cancer patients.   Some forms of prostate cancer cannot be treated by focal therapies.  Also, not all urologists agree on focal therapies, according to the Urology Times:

“We’re starting to do some investigative studies on this, but it’s still premature to say whether it’s going to be the future.

For low-grade disease, it’s certainly worth a try because nothing is really lost. For high-grade disease, I don’t know that it’s appropriate—we don’t have the data.

It used to be that all grades of cancer were treated either by radiation or surgery. Now surveillance is preferred for low-grade cancer with close follow-up, including repeated prostate biopsies. Rather than having to do that, why not just do focal therapy—HIFU or cryosurgery? I’d rather follow up with PSAs than biopsies.”

Prostate biopsies could be avoided with MRI

https://www.yahoo.com/news/prostate-biopsies-could-avoidable-mris-study-090415741.html

A quarter of men suspected of having prostate cancer could avoid invasive and potentially dangerous biopsies with the help of MRI scans, researchers reported Friday.

Magnetic resonance imaging (MRI) could also reduce the number of men over-diagnosed with the disease by five percent, they detailed in a study published in The Lancet.

More PSA Tests

My PSA has risen to 4.4 as of my most recent test, roughly 10% above the test over a year ago.  Anything over 4 is officially considered high for my age group.   My PSA has been rising almost 10% a year on average for almost 9 years.  Best I can tell, this simply means that my prostate has been growing almost 10% a year, most likely due to a common benign condition known as BPH.  A sudden increase on PSA or detection of lumps on a DRE by a physician would likely lead to additional testing.

PSA testing is still controversial, with new studies and policies recommending against routine testing.  There are also experts who still think it is a valuable tool, highlighted by Ben Stiller’s recent comments.

http://www.livescience.com/56371-ben-stiller-prostate-cancer-psa.html

One problem with the PSA test is that it often suggests that men have prostate cancer when they do not have cancer, according to the USPSTF. About 75 percent of men with abnormally high levels of PSA do not have cancer. These so-called false positive results can lead to anxiety and unnecessary follow-up tests, the USPSTF says.

 

 

Aspirin and Prostate Cancer

Can Aspirin reduce the risk of aggressive prostate cancers?

 

The analysis found that regular aspirin resulted in a 24% lower risk of developing lethal cancer after being diagnosed with an early stage of the disease, and a 39% reduced risk of dying from prostate cancer.

But aspirin had little effect when researchers looked at overall incidence of prostate cancer among the participants. “It was after diagnosis of prostate cancer that there appeared to be a benefit,” said Christopher Allard, lead author of the study and a urologic oncology fellow at Harvard Medical School. “It doesn’t affect the incidence, but it affects the progression.”

http://www.wsj.com/articles/regular-use-of-aspirin-may-lower-mens-risk-of-advanced-prostate-cancer-1451946945

More on the 4KScore

Since Medscape saw fit to remove their content from our previous post, here’s a newer article about how the 4KScore may help reduce unecessary prostate biopsies:

clinicaloncology.com

“The role of the 4Kscore,” explained Sanoj Punnen, MD, an assistant professor in the Department of Urology at the University of Miami Miller School of Medicine and Sylvester Comprehensive Cancer Center, in Florida, “is to determine which patients are most likely to have an aggressive cancer and would, therefore, benefit from … biopsy. This allows us to forgo biopsies in men who are unlikely to ever suffer any serious consequences from a high-grade cancer.”

More on the 4KScore here:

http://4kscore.opko.com/

Another new biomarker for prostate cancer

This one is a little different than some others.  University of Michigan researchers may have found a way to distinguish aggressive and less aggressive cancers:

“If this biomarker does indeed control the growth of prostate cells, it’s a new signal that’s not been seen before and could provide a potential new drug target for prostate cancer,” Franceschi said. “It could also be a potential biomarker to discriminate between fast and slow growing tumors.”

 

 

The 4Kscore? Is it Better than What We Had Before?

It seems like there is a new test every few months.  I’ve had a few of them as you may have seen in the archives of this blog.  Now there is a 4KScore test,

A newly available commercial blood test performs better than a commonly used online risk calculator in predicting which men with an elevated prostate-specific antigen (PSA) level will ultimately turn out, on biopsy, to have high-grade disease.

 

http://www.medscape.com/viewarticle/825626

PSA Testing a Hoax?

According to Richard Albin, PhD, who discovered the PSA in 1970, current testing standards may indeed be a hoax.

http://www.amazon.com/The-Great-Prostate-Hoax-Medicine/dp/1137278749/?tag=prostateblog-20

Every year, more than a million  men undergo painful needle biopsies for prostate cancer, and upward of 100,000 have radical prostatectomies, resulting in incontinence and impotence. But the shocking fact is that most of these men would never have died from this common form of cancer, which frequently grows so slowly that it never even leaves the prostate. How did we get to a point where so many unnecessary  tests and surgeries are being done? In The Great Prostate Hoax, Richard J. Ablin exposes how a discovery he made in 1970, the prostate-specific antigen (PSA), was co-opted by the pharmaceutical industry into a multibillion-dollar   business. He shows how his discovery of PSA was never meant to be used for screening prostate cancer, and yet nonetheless the test was patented and eventurally approved by the FDA in 1994. Now, doctors and victims are beginning to speak out about the harm of the test, and beginning  to search for a true prostate cancer-specific  marker.

MRI-Ultrasound Fusion Biopsy

It’s called the Artemis System or the UroNav Fusion Biopsy System with DynaCAD software, and it may be coming to a hospital or urologist near you.  I had a similar procedure a few years ago at the NIH, though this research was also exploring the use of high definition MRI as a non-invasive alternative to biopsy.  Will it reduce the number of false negatives for prostate biopsies or improve localization of a known tumor?  We can only hope so!

“As with PCs in 1975,” said Dr. Marks, “there are some deniers, but not many once they see the dramatic results of fusion-guided biopsies. Despite the cost, the learning curve, the new technology, and the time investment, the train has left the station.”

In fact, he said that his department believes MRI-ultrasound fusion represents the gold standard for prostate biopsies today. Nationally, said Dr. Marks, urologists use MRI-ultrasound fusion in less than 1% of the 1 million prostate biopsies performed yearly. But that will change quickly, he said, as heavyweight imaging companies continue putting their marketing muscle behind the technology.”

http://urologytimes.modernmedicine.com/urology-times/news/mri-guiding-future-prostate-cancer-diagnosis?page=full