Itraconazole is an oral, generic, and commercially available antifungal drug with a long safety record when used at doses ranging from 200 to 600 mg daily.
Itraconazole has been shown in cellular and animal models to be a potent angiogenesis inhibitor as well as a Hedgehog pathway antagonist; both pathways are considered important in prostate cancer. Itraconazole has not previously been tested as an antineoplastic agent, but given its well-established safety profile, the gap between further preclinical studies and human clinical trials can be narrowed to accelerate development of this agent as a putative anticancer drug. The investigators hypothesize that itraconazole will prevent PSA progression in a significant proportion of men with metastatic CRPC and that it will have an acceptable safety profile at both doses. Itraconazole may ultimately delay the need for chemotherapy in these men.