Inclusion Criteria:

- Patient has hormone-refractory prostate cancer (HRPC) as evidenced by PSA progression
or progression of measurable disease.

- Patient has greater than 25% increase in 2 consecutive tests in which the first
increase in PSA should occur a minimum of 1 week apart.

- Patients on androgen deprivation treatment and will continue on androgen deprivation
treatment during study participation except for patients who are post orchiectomy.

- Patient has evidence of metastatic disease by positive bone scan or evidence of
progressive metastatic disease by CT scan.

- Patient has been treated with at least 1 prior hormone therapy or is post
orchiectomy.

- Patient has been previously treated at a minimum for an 8-week treatment period on a
docetaxel-based regimen for metastatic HRPC.

- Patient has PSA at least 5 ng/mL or greater.

- Patient has testosterone less than 50 ng/dL.

- Patient ECOG performance status of 0 or 1.

- Patient has life expectancy of greater than 8 weeks.

- Patient meets lab values: A. Absolute neutrophil count at least 1,500/mm^3 or
greater; B.Platelet count at least 100,000/mm^3 or greater; C. Serum creatinine at
least 1.5 mg/dL or less or creatinine clearance at least 60 mL/min or greater; D.
Bilirubin less than 2.0 mg/dL. E. AST and ALT less or equal to 2.5 times upper limit
of normal

- Any chemotherapy, major surgery, or irradiation must be completed at least 4 weeks
prior to study drug.

- Patient recovered from clinically significant toxicities from prior treatment.

Exclusion Criteria:

- Prior treatment with 2 or more prior chemotherapy regimens.

- Concurrent treatment with an estrogen-containing agent including diethylstilbestrol
(DES).

- Prior flutamide (Eulexin) within past 4 weeks, prior bicalutamide (Casodex) within
past 6 weeks, or prior nilutamide (Nilandron) within past 6 weeks.

- Prior strontium or samarium or other radioisotope therapy.

- Prior radiation therapy to greater than 25% of the bone marrow (e.g., no whole pelvic
irradiation is allowed).

- Uncontrolled congestive heart failure or angina, patients with a history of
myocardial infarction within 2 months of enrollment.

- Patients with uncontrolled hypertension.

- Pre-existing cardiac, pulmonary, neurologic or other disease that would preclude
study participation.

- Documented untreated central nervous system (CNS) metastases. However, patients with
treated CNS metastases that have been stable are eligible.

- Any significant concurrent disease or illness, or psychiatric disorders or alcohol or
chemical abuse that would preclude study participation.

- Active secondary malignancy except non-melanoma skin cancers.

- Known, active infection, or known HIV positive or presence of an AIDS related
illness.