Prostatic Neoplasms

Inclusion Criteria

- Histologically or cytologically confirmed adenocarcinoma of the prostate
 - Patients diagnosed with progressive bone predominant metastatic Castration-Resistant Prostate Cancer (CRPC) /Hormone Refractory Prostate Cancer (HRPC) with at least 2 skeletal metastases on imaging with no lung, liver, and/or brain metastasis (lymph node only metastasis is allowed) 
 - Known hormone refractory disease
 - No intention to use cytotoxic chemotherapy within the next 6 months
 - Either regular (not occasional) analgesic medication use for cancer related bone pain or treatment with external bean radiation therapy (EBRT) for bone pain within previous 12 weeks
 - Age >/= 18 years
 - Race is Asian
 - Eastern Co-operative Oncology Group (ECOG) Performance Status (PS): 0-2
 - Life expectancy >/= 6 months
 - Adequate bone marrow, liver and renal function as assessed by the Laboratory required by protocol

Exclusion Criteria

- Treatment with an investigational drug within previous 4 weeks prior to screening, or planned during the treatment or follow-up periods
 - Eligible for docetaxel treatment, i.e. subjects who are fit enough, willing and who are located where treatment with docetaxel is available
 - Treatment with cytotoxic chemotherapy within previous 4 weeks prior to screening, or failure to recover from adverse events due to cytotoxic chemotherapy administered more than 4 weeks prior to screening (however ongoing neuropathy is permitted)
 - Prior hemibody external radiotherapy is excluded.  Subjects who received other types of prior external radiotherapy are allowed provided that the bone marrow function is assessed and meets the protocol requirements for hemoglobin, absolute neutrophil count and platelets.
 - Received systemic therapy radionuclides (e.g., strontium-89, samarium-153, rhenium-186, rhenium-188, or radium-223 dichloride) for the treatment of bony metastases 
 - Blood transfusion or erythropoetin stimulating agents within the previous 4 weeks prior to screening
 - Other malignancy treated within the last 3 years (except non-melanoma skin cancer or low-grade superficial bladder cancer)
 - Visceral metastases as assessed by abdominal/pelvic computed tomography (CT) or other imaging modality 
 - Presence of brain metastases
 - Lymphadenopathy exceeding 3 cm in short-axis diameter
 - Any size pelvic lymphadenopathy if it is thought to be a contributor to concurrent hydronephrosis
 - Imminent or established spinal cord compression based on clinical findings and/or magnetic resonance imaging (MRI). Subjects with history of spinal cord compression should have completely recovered.
 - Received local practice implant therapy containing lodine-125 or Palladium-103 for the primary lesion of prostate cancer within the 6 months prior to screening.
 - Any other serious illness or medical condition