PII Trial of Docetaxel/Prednisone w/Sargramostim for HRPC

This is a Phase II, open-label study in male patients with metastatic HRPC. Each cycle will be 21 days (3 weeks). Patients will receive the following drugs: * Docetaxel 75 mg/m2 IV given over 1 hour on Day 1. * Prednisone 5 mg orally twice daily beginning on Day 1 and continuing until disease progression. * Sargramostim 250 mcg/m2 SC on Days 2-15 of each cycle. Patients will be evaluated every 4 cycles (12 weeks) for response using RECIST criteria. PSA response will be evaluated according to the National Cancer Institute (NCI) PSA Working Group Criteria. To evaluate the safety of this drug combination, patients will be evaluated at each clinic visit for adverse events. Toxicities will be assessed per National Cancer Institute (NCI) CTCAE Version 3.0. Those patients achieving stable disease or better will continue therapy. Those patients experiencing progressive disease will be taken off study. Patients will receive a maximum of 10 cycles of treatment.