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New Immunotherapy Drug Effective In Reducing PSA Levels In Prostate Patients

A recent research study has shown that a new immunotherapy drug has proven effective in reducing prostate-specific antigen levels in a specific subset of prostate cancer patients.

A Targeted Approach

The new study, recently published in the Journal of Clinical Oncology, revealed how prostate cancer patients treated with the immunotherapy drug pembrolizumab responded favorably to the treatment under specific circumstances. The drug, which was designed to combat cancers of a particular type, works by stimulating the body’s T-cells to target tumors that possess the MMR/MSI genetic marker.

Researchers found patients with MMR/MSI-positive prostate cancers treated with pembrolizumab responded favorably in around 50 percent of cases. PSA levels were found to have been reduced in these patients significantly — anywhere between 60% and 80%, according to scientists. The additional good news comes in the form of a correlation between plummeting PSA levels and tumor size — in cases where the drug reduced levels of the cancer-linked hormone in the blood, patients experienced tumor shrinkage of up to 40%.

That’s the Good News, Now Here’s the Bad News

These research results are strikingly upbeat, as well they should be — the positive results are, in a word, incredibly outstanding. However, there’s one thing that you can’t lose sight of in this case: this treatment is only applicable to prostate cancers that have MMR/MSI genetic markers. Not only that, around half of the patients that had MMR/MSI-tagged prostate cancers responded to this treatment. This means that even if a patient is suffering from this type of prostate cancer, it’s a coin flip as to whether the immunotherapy drug will be effective.

These are all sobering thoughts, of course — especially if you have fears about your own prostate health. But even though the new success that pembrolizumab has shown in treating a subset of a subset of this prostate cancer type is a mixed bag, it’s proof positive that modern medical science is striving ever forward in researching new treatment methods for prostate cancer. As time marches on, these treatment methods will only become stronger and more effective for many more types of prostate cancer. With these successes so promising, the future likely holds even more good news for prostate cancer patients and their families.

Dr. David Samadi | Robotic Prostate Surgeon

About is a resource created by Dr. David Samadi in order to raise awareness and get more men to receive prostate cancer treatment. The information is strictly general and you should always discuss with your doctor issues concerning your health.


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