Prostate Cancer Vaccine Enhanced

Prostate cancer vaccine Provenge aided with PI3K inhibitor adjuvant

(RxWiki News) While widely researched, highly sought after and well-funded, vaccines for most cancers aren't easy to implement. Since a vaccine trains the immune system to attack foreign cells, and cancer cells are still human, the level of precision is difficult.

A team or researchers from Ireland, working with an existing vaccine for prostate cancer, decided to target the problem from another angle. They enhanced the body's own immune response against tumor cells by giving doses of an experimental compound known as PI3K inhibitors.

Cancers frequently engage in chemical warfare of their own, pumping out molecules, including PI3K, to turn off immune cells.

"Ask your oncologist about Provenge."

H.G. Mills, Ph.D., from Trinity College in Dublin, attempted to improve the immune response to the vaccine, and found that PI3K inhibitors produced the best results in laboratory experiments.

The vaccine used in the study - Provenge (sipuleucel-T) - was approved by the U.S. Food and Drug Administration (FDA) in 2010 to treat metastatic prostate cancer that does not respond to any other available therapy. This state of the disease is dubbed metastatic castration-resistant prostate cancer.

The vaccine must be developed separately for each individual, resulting in a cost of $90,000 for a complete six-week treatment of three separate doses. A study found that life expectancy was extended by an average of four months.

The current study specifically tested the concept of using P13K inhibitors in mice, which have a similar immune system to humans. Researchers believe that the findings will directly translate over into enhancing the performance of the prostate cancer vaccine as well as other cancer immunotherapy.

This study is an attempt to place the groundwork for eventual approval of the prostate cancer vaccine Provenge in early cases of prostate cancer.

Results were published in the journal Cancer Research.

Dr. Mills has patented the findings with intent to license them to a company, TriMod Therapeutics, which he co-founded.

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Review Date: 
March 10, 2012