Standard Dose Versus High Dose and Versus Extended Standard Dose Radium-223 Dichloride in Castration-resistant Prostate Cancer Metastatic to the Bone

Inclusion Criteria

• •Histologically or cytologically confirmed adenocarcinoma of the prostate
• •Castration-resistant disease defined as:
• •* Serum testosterone level: ≤ 50 ng/dL (1.7 nmol/L)
• •* Bilateral orchiectomy or maintenance on androgen ablation therapy with luteinizing-hormone-releasing hormone (LHRH) agonist or antagonist, or polyestradiol phosphate
• •* Serum PSA (Prostate specific antigen) progression defined as 2 subsequent increases in PSA over a previous reference value (a minimum of 2 ng/mL \[μg/L\]) OR
• •* Radiographic evidence of disease progression in bone (according to Prostate Cancer Clinical Trials Working Group 2 \[PCWG2\] criteria) with or without PSA progression
• •Eastern Cooperative Oncology Group performance status (ECOG PS) 0 to 2. In case of ECOG PS 2, the PS has to be due to metastatic prostate cancer to the bone.
• •Two or more skeletal metastases (≥ 2 hot spots) on bone scintigraphy within 8 weeks of randomization