According to a pooled analysis of results from two large clinical trials, the immunotherapy agent Provenge® (D9902A) improves survival in patients with hormone-refractory prostate cancer.
The prostate is a gland of the male reproductive system that produces some of the fluid that transports the sperm during male ejaculation. Prostate cancer is a disease in which cancer cells form in the tissues of the prostate. After skin cancer, prostate cancer is the most common form of cancer diagnosed in men. However, overall survival rates for all stages of prostate cancer have improved dramatically over the past 20 years. Current treatment options for prostate cancer include watchful waiting, surgery, chemotherapy, radiation or hormonal therapy. Hormonal therapy is designed to lower the presence or block the effects of testosterone, which stimulates the growth of hormone-dependent types of prostate cancer. Some types of prostate cancer can become resistant to hormonal therapy and will then require a different treatment approach; this condition is known as hormone-refractory prostate cancer.
The Provenge vaccine is made from the proteins found in prostate cancers. It is engineered to introduce a target to the patient’s immune system; the immune system is then triggered to mount a response against that target. Hormone refractory prostate cancer can be difficult to treat, so novel approaches, such as immune stimulating vaccines like Provenge, are providing hope of a better outcome for these patients.
Two large clinical trials directly comparing Provenge to placebo (inactive substitute) have been conducted to evaluate Provenge in men with hormone-refractory prostate cancer. Researchers recently pooled the data from these two trials, referred to as the D9901 and D9902A studies. Overall, the men who received Provenge had an improved duration of survival of 23 percent over those who received placebo. Furthermore, at three years, significantly more men who were treated with Provenge were alive. The most common side effects associated with Provenge were chills and fever lasting one to two days.
Patients with hormone-refractory prostate cancer may wish to speak with their physician regarding their individual risks and benefits of participating in a clinical trial further evaluating Provenge or other promising therapeutic agents. Two sources of information regarding ongoing clinical trials include the National Cancer Institute (www.cancer.gov) and www.cancerconsultants.com.
Reference: Dendreon Corporation. Dendreon’s Second Randomized Phase 3 D9902A Trial Shows Provenge Extends Survival in Patients with Advanced Prostate Cancer. Available at: http://investor.dendreon.com/ReleaseDetail.cfm?ReleaseID=169318. Accessed July 2005.