 B. Patients must have metastatic progressive androgen-independent prostate cancer. There must be radiographic evidence of disease by computed tomography CT scan or bone scan after primary treatment that has continued to progress despite hormonal agents. Progression requires that a measurable lesion is expanding, new lesions have appeared, andor that prostatic specific antigen PSA is continuing to rise on successive measurements. Patients must have progressive disease after receiving 1 prior docetaxel-based cytotoxic chemotherapy. Patients on flutamide for the prior 6 months must have disease progression at least 4 weeks after withdrawal. Patients on bicalutamide or nilutamide must have progression at least 6 weeks after withdrawal. 