Results from Dendreon’s pivotal phase III study (D9901) of Provenge (sipuleucel-T) were published in the Journal of Clinical Oncology. The double-blind, placebo-controlled study showed that the group of men with asymptomatic, metastatic, androgen-independent prostate cancer who received Provenge had a median survival time 4.5 months longer than the median survival seen in the group assigned to receive placebo.
For the men who received Provenge, there was a 41% overall reduction in the risk of death. In addition, 34% of patients receiving Provenge were alive 36 months after treatment, compared to 11% of patients randomized to receive placebo.
Patients in the Provenge arm had a 31% delay in their time to disease progression compared to patients in the placebo arm. Furthermore, patients receiving Provenge had an approximately eight-fold increase in their T-cell immunity after treatment compared to the placebo group.
The results mean Provenge is the first cancer immunotherapy to demonstrate a survival benefit in a randomized phase III study.
The data will form the basis of Dendreon’s biologics license application (BLA) to the FDA for marketing approval, which the company plans to submit later this year.
“This trial is an important milestone in the development of new treatments for prostate cancer patients,” said Dr Eric Small, professor of medicine and urology at the University of California, San Francisco and lead author of the publication. “In addition to the observed survival benefit, Provenge has a very favorable toxicity and safety profile, with the most common side effects being low grade fevers and chills. A favorable benefit-to-risk profile will be appealing to patients with advanced stage prostate cancer who currently have few appealing treatment options available to them.”