Prostate Cancer Vaccine Shows Few Side Effects

The newly approved therapeutic prostate cancer vaccine, Provenge, is safe and has few side effects, a new study finds. In April, the FDA approved the vaccine for use in men with advanced prostate cancer who had failed hormone therapy.

"Provenge was approved based on both safety and clinical data," says lead researcher Simon J. Hall, MD, chair of urology at Mount Sinai Medical Center in New York City.

This safety data shows that there are very limited side effects, Hall adds. The advantage of the vaccine for patients with metastatic hormone-resistant prostate cancer is that it has fewer side effects than chemotherapy, which is the only other treatment option for these patients, Hall explains.

In addition, Provenge has improved survival over chemotherapy, he adds. The average survival time for men given Provenge is 4.5 months, although some patients saw their lives extended by two to three years.

"This is a newly available treatment, with very limited side effects, compared to anything else that a man would be considering in this state," Hall says.

Data from four phase 3 trials, which included 904 men randomized to either Provenge or placebo, showed the vaccine extended survival, improved quality of life, and had only mild side effects.

In fact, more than 83% of the men who received Provenge were able to do perform activities without any restrictions, the researchers note.

In terms of side effects, the most common were flu-like symptoms such as chills, fever, and headache, which were seen in 3.5% of the men. Usually it took only a day or two for the symptoms to resolve.

More serious side effects, such as infusion reactions, affected 3.5% of the patients. Cerebrovascular problems affected 3.5% of those who received the vaccine and 2.6% of those who received placebo, Hall's group found.

Provenge is a therapeutic (not preventive) vaccine that is made from the patient's own white blood cells. Once removed from the patient, the cells are treated with the drug and placed back into the patient. These treated cells then cause an immune response, which in turn kills cancer cells, while leaving normal cells unharmed.

Source: Brigham and Women's Hospital