Study on Prolonging Bone Metastasis-Free Survival in Men With Hormone Refractory Prostate Cancer

Inclusion Criteria: * men with histologically confirmed prostate cancer * bilateral orchiectomy at least 6 months before randomization or continuous androgen-deprivation therapy (ADT) with a gonadotropin releasing hormone (GnRH) agonist or antagonist for at least 6 months before randomization * total testosterone level less than 50 ng/dL, * hormone refractory (androgen independent) prostate cancer demonstrated during continuous ADT/post-orchiectomy defined as: 3 consecutive prostate-specific antigen (PSA) values with PSA1 \< PSA2 \< PSA3, each PSA value must be separated by at least 2 weeks, PSA2 and PSA3 greater than or equal to 1.0 ng/mL, * high risk for development of bone metastasis defined as PSA value greater than or equal to 8.0 ng/mL, obtained no more than 3 months before randomization OR PSA doubling time less than or equal to 10.0 months Exclusion Criteria: * prior or current evidence of radiographically detectable bone metastasis * known prior or current evidence of any metastatic involvement of distant organs (lymph node metastases in any region is acceptable) * prior or current intravenous bisphosphonate administration