Name of the Trial
Phase II Study of Sorafenib in Patients with Metastatic Androgen-Independent Prostate Cancer. See the protocol summary at http://www.cancer.gov/clinicaltrials/NCI-04-C-0262.

Principal Investigator
Dr. William Dahut, NCI CCR

Why This Trial Is Important
Prostate cancer cells often grow in response to hormones called androgens, which are naturally produced by the body. In most men with prostate cancer that has spread (metastasized), treatment to suppress these hormones is initially very effective in controlling cancer cell growth. However, over time, prostate cancer acquires the ability to grow without the help of hormones. This is called androgen-independent prostate cancer.

Many new drugs are currently being tested for the treatment of metastatic, androgen-independent prostate cancer. Sorafenib (Nexavar) is a type of anticancer drug that belongs to a class of drugs called small-molecule inhibitors. Small-molecule inhibitors block the activity of proteins in cancer cells that help promote cell division and survival.

Sorafenib inhibits the activity of at least three cancer-cell proteins involved in cell signaling - the transmission of information within a cell or between cells. The inhibition of multiple signaling proteins blocks both tumor-cell division and the growth of new blood vessels (angiogenesis) that feed the tumor.

"In the laboratory, sorafenib had activity against both signal transduction and angiogenesis in prostate cancer," explained Dr. Dahut. "We believe that angiogenesis is an important target in prostate cancer. Patients who have more vascular tumors at the time of initial diagnosis are more likely to eventually develop metastatic disease."

Who Can Join This Trial
Between 22 and 46 patients with metastatic prostate cancer that has progressed despite the use of hormone therapy will be enrolled in this trial. See the list of eligibility criteria at http://www.cancer.gov/clinicaltrials/NCI-04-C-0262.

Study Sites and Contact Information
The study is taking place at the NIH Clinical Center in Bethesda, MD. For more information, call the NCI Clinical Trials Referral Office at 1-888-NCI-1937. The toll-free call is completely confidential.