Sorafenib and Docetaxel in Patients With Prostate Cancer That Did Not Respond to Previous Hormone Therapy

OBJECTIVES: Primary * To determine the proportion of patients achieving a 50% reduction in serum PSA from baseline in patients with androgen-independent prostate cancer (AIPC) receiving sorafenib tosylate and docetaxel. Secondary * To estimate the progression-free survival of patients with AIPC. * To quantify the number and percent of patients who have stable disease at 6 months of therapy (failure to progress). * To estimate median time to progression for all patients. * To estimate the objective response rate of patients with AIPC treated with this regimen. * To measure the percentage of patients surviving at 2 years. * To determine the toxicities and estimate toxicity rates for patients treated with this regimen. * To measure changes in tumor vasculature in response to therapy in selected patients with dynamic contrast-enhanced MRI (DCE-MRI) and correlate primary and secondary objectives to these measurement changes. * To measure changes in serum HMGB1 in response to therapy and correlate primary and secondary objectives with these changes. * To measure changes in serum cathepsin D in response to therapy and correlate primary and secondary objectives with these changes. OUTLINE: Patients receive oral sorafenib tosylate twice daily on days 2-19 and docetaxel IV on day 1. Treatment repeats every 21 days for up to 10 courses. Patients then receive oral sorafenib tosylate alone twice daily on days 1-19 with treatment repeating every 21 days in the absence of disease progression or unacceptable toxicity. Patients undergo blood collection periodically to measure serum HMGB1 and cathepsin D levels before and after therapy.