Targeted Therapies for Prostate Cancer

Prostate cancer is the second leading cause of cancer deaths in males in the USA. Prostate cancer is a highly morbid disease, especially upon its progression toward metastatic disease. Hormonal therapy is the mainstay of treatment in patients with progressive disease, but, eventually most patients develop hormone-insensitive disease. Docetaxel-based chemotherapy increases overall survival in patients with metastatic hormone-insensitive prostate cancer. Other cytotoxic chemotherapies either in combination with docetaxel or as single agents are currently being evaluated in metastatic prostate cancer patients. There is a clear need for additional treatment options in this growing group of patients. Novel agents targeting specific aberrant molecular pathways in prostate cancer are actively being investigated in clinical trials. The development of novel agents requires thoughtful clinical trial design, selection of appropriate study endpoints and/or surrogate markers of efficacy, and close monitoring of adverse events. Novel agents discussed in this chapter include antitubulin agents, anti-mitotic agents, various signal transduction inhibitors, angiogenesis inhibitors, vascular targeting agents, and immunotherapy. These agents are being developed with a goal of maximizing tumor-specific cell death while minimizing adverse toxicities. Several novel agents are currently in phase III clinical trials whereas the majority remains in early clinical development. Our improved understanding of prostate tumorigenesis will undoubtedly contribute to further development of novel targeted therapies for prostate cancer.