Dendreon Corporation, a biotechnology company, announced updated survival data from patients with advanced prostate cancer with Gleason Scores of seven and less who participated in its completed and previously reported Phase 3 trial (D9901) of Provenge, the company's investigational immunotherapy for the treatment of prostate cancer.
Patients with Gleason Scores of seven and less receiving Provenge had a significant survival advantage, having on average an 89 per cent overall increase in their survival time as compared to placebo. This benefit is reflected by a prolongation in the median survival time in patients receiving Provenge by 8.4 months (30.7 months versus 22.3 months). At 30 months from randomization, the survival rate for Provenge-treated patients is 3.7 times higher than for patients receiving placebo
Consistent with previous reports, a majority of those patients in D9901 who are still alive have received treatment with Provenge and will continue to be followed according to study protocol. The company expects to present this and other updated data at major scientific meetings throughout the year.
Prostate cancer is the most common non-skin cancer in the US. More than one million men in the US have prostate cancer, with an estimated 220000 cases diagnosed and 28900 deaths in 2003.
"This is the longest survival benefit ever reported in a Phase 3 study in late stage prostate cancer," said Dr John Corman director of the Virginia Mason Comprehensive Prostate Cancer Clinic and assistant clinical professor of Urology at the University of Washington in Seattle. "With the combination of this exciting new survival data and favorable side effect profile, Provenge has the potential to change the way we treat prostate cancer in the future."
These updated survival data are consistent with other previously reported data from the D9901 trial that showed significant clinical benefit from Provenge treatment for men with a Gleason Score of seven and less. For these men, the average time to disease progression is more than two-fold longer than that for patients treated with placebo and the average time to experiencing cancer-related pain is more than 2.5 times longer than that for patients treated with placebo. Treatment was well tolerated, with mild infusion-related fevers and chills the most common adverse events. No benefit has been seen in men with Gleason Scores of eight and higher.
Last year, Dendreon also released data confirming Provenge's mechanism of action based on T-cell mediated immune response. These data showed that among men treated with Provenge, those with a Gleason Score of seven and less demonstrated a T-cell mediated immune response 7-fold greater than men with a Gleason Score of eight or more.
"Based on the strength of this survival data, which is consistent with all of the data gathered to date on our other endpoints in the trial for patients with Gleason Scores of seven and less, we are more enthusiastic than ever regarding the pivotal role that Provenge may play in providing a new and well tolerated targeted therapy for prostate cancer patients," said Mitchell Gold, MD, president and CEO of Dendreon. "The results from this study represent an important milestone in the fight against prostate cancer and indicate that Provenge may provide for a well-tolerated treatment option that offers patients a potential survival advantage."