Efficacy and Safety Study of Xyotax to Treat Prostate Cancer

Prostate cancer is the second leading cause of cancer death in American men. Hormonal ablation, in the form of medical or surgical castration, is the cornerstone of management for metastatic prostate cancer; however, treatment options for a patient in whom androgen ablation fails are limited. Docetaxel and paclitaxel, taxanes that are cell cycle specific, play a major role in advanced hormone-refractory prostate cancer treatment. In preclinical studies, Xyotax, a conjugate of paclitaxel with enhanced permeability and retention in tumor tissue, has an improved therapeutic profile, with both decreased systemic drug-related toxicities and enhanced efficacy. Xyotax as a single agent has been studied in a broad variety of syngeneic and xenogeneic tumor models. Recognizing that taxanes are active in prostate cancer and preclinical data reports activity with Xyotax in docetaxel and paclitaxel resistant cell lines, there is significant rationale to develop this agent in prostate cancer. Thus, a phase II study is needed to evaluate the antitumor activity in two subsets of hormone refractory prostate cancer patients: those with no prior systemic and those with one prior systemic therapy.