Vaccine appears to increase prostate cancer survival

APC8015 (Provenge), which is still under investigation, "appears to prolong survival," according to lead investigator Eric J. Small, MD, who led the phase III randomized, placebo-controlled trial.

"At 3 years, three times as many patients are alive compared with those on placebo," said Dr. Small, professor of medicine and urology, University of California, San Francisco.

3-year trial The trial included 127 asymptomatic, metastatic prostate cancer patients who had failed to respond to hormonal therapy. They were randomized 2:1, with 82 receiving APC8015, while 45 were on placebo. The drug was administered intravenously over 30 to 60 minutes at week 0, with a follow-up at week 2. The therapy was completed at week 4.

All patients were followed for 36 months. The drug had only minor, flu-like side effects that were treated with acetaminophen and resolved within 24 hours.

"When you look at those data, you'll see that 34% of the patients were alive at 36 months, compared with 11% in the placebo group. That was encouraging," Dr. Small told Urology Times during an interview at the 2005 Multidisciplinary Prostate Cancer Symposium here.

"My interpretation is that this is a therapy that appears to prolong survival. A therapy that prolongs life, yet avoids the side effects of other therapeutic approaches is clearly attractive to patients and physicians alike," he said.

Philip Kantoff, MD, director of The Lank Center for Genitourinary Oncology and chief of the division of solid tumor oncology at the Dana-Farber Cancer Institute, Boston, said the APC8015 trial is potentially a landmark study because it represents the first vaccine approach in prostate cancer-or any solid tumor-to demonstrate a survival advantage. This is proof of principle that it works in men with advanced prostate cancer, he said.