Inclusion Criteria:

- Histologic diagnosis of prostate adenocarcinoma.

- Patient must have progressive metastatic prostate cancer despite adequate medical or
surgical castration therapy.

- Serum testosterone < 50 mg/ml.

- Patients who have previously received docetaxel must meet BOTH of the the following
criteria:

- reason for docetaxel discontinuation must NOT have been progression of disease
while receiving drug (i.e. progression of cancer must have been AFTER docetaxel
discontinuation) AND

- All docetaxel-related toxicities must have resolved to < grade 1 (with the
exception of alopecia) and the pt must be eligible by other criteria

Exclusion Criteria:

- Use of red blood cell or platelet transfusions within 4 weeks of treatment.

- Use of hematopoietic growth factors within 4 weeks of treatment.-Prior cytotoxic
chemotherapy and/or radiation therapy within 4 weeks of treatment.

- Bone scan demonstrating confluent lesions involving both axial and appendicular
skeleton ("superscan").

- Prior radiation therapy encompassing >25% of skeleton.Prior treatment with
89Strontium or 153Samarium containing compounds (e.g. Metastron®, Quadramet®).

- Platelet count <150,000/mm3.

- Absolute neutrophil count (ANC) <2,000/mm3.

- Hematocrit <30 percent or Hemoglobin < 10 g/dL.

- Abnormal coagulation profile (PT or INR, PTT) > 1.3 x upper limit of normal (unless
on therapeutic anticoagulation).

- -Serum creatinine >2.5 mg/dL.

- AST (SGOT) >2.5x ULN.

- Bilirubin (total) >1.5x ULN.

- Serum calcium >11 mg/dL.

- Active serious infection.

- Active angina pectoris or New York Heart Association Class III-IV.

- ECOG Performance Status >2.

- Life expectancy <6 months.

- Deep vein thrombosis and/or pulmonary embolus within 1 month of study entry.

- Other serious illness(es) which might preclude completion of this study or interfere
with determination of causality of any adverse effects experienced in this study.

- Prior anti-PSMA monoclonal antibody therapy with the exception of ProstaScint®.

- Prior investigational therapy within 6 weeks of treatment.

- Known history of HIV.

- Known history of myelodysplastic syndrome or leukemia