The double blind, placebo-controlled trials will seek to confirm the results obtained in earlier studies of Dendreon Corporation's proprietary prostate cancer vaccine. Those studies indicated the effectiveness of Dendreon's immunotherapy in delaying the progression of prostate cancer.
"There are no effective treatment options currently available to men with advanced hormone-refractory prostate cancer," said Christopher Henney, Ph.D., D.Sc., president and chief executive officer of Dendreon. "Our Phase III studies will determine if our immunotherapy product can offer benefit to such patients."
Dendreon's therapeutic vaccine aims to jumpstart a patient's natural defenses against cancer. It involves the isolation of the patient's dendritic cells -- immune system cells that identify foreign proteins -- and the activation of these cells through the use of a prostate tumor vaccine.
Results of Phase I and Phase II trials indicate that the treatment is safe and that it does stimulate immune activity. Tumor regressions occurred in some patients and the vaccine appeared to delay tumor progression.
To be eligible for the present study, patients must have metastatic prostate cancer that has progressed following hormone therapy. Patients must also be free of cancer-related pain.
Patients will receive a total of three immunotherapy treatments over 30 days. Each treatment consists of an apheresis procedure to collect blood cells, followed two days later by an infusion of dendritic cells containing the vaccine.
Control patients who receive placebo will have the option of receiving the immunotherapy if their disease progresses during the study, Dendreon said.
The first Phase III trial is led by Dr. Eric Small at the University of California, San Francisco. Other participating clinical sites include City of Hope National Medical Center, Duarte, Calif.; Northwest Medical Specialties, Tacoma, Wash.; Providence Medical Center, Portland, Ore.; Sidney Kimmel Cancer Center, San Diego, Calif., and University of Washington, Seattle, Wash.
The second Phase III trial will be led by Dr. Patrick Burch, of the Mayo Clinic. Participating centers will be located in Minnesota, Philadelphia, New York and Maryland.
Dendreon Corporation is a private biotechnology company that develops and commercializes novel products for the treatment of cancer, infectious disease and autoimmunity through innovative manipulation of the immune system.