Zoledronate in Preventing Skeletal (Bone)-Related Events in Men Who Are Receiving Androgen Deprivation Therapy For Prostate Cancer and Bone Metastases

Zoledronic acid decreases the risk of skeletal related events in men with prostate cancer metastatic to bone and disease progression after primary hormonal therapy.

This study is designed to evaluate whether earlier treatment with zoledronic acid will further decrease the risk of skeletal related events. This is a randomized, double-blind, placebo-controlled, multicenter study followed by an open-label study. Patients are stratified according to ECOG performance status (0-1 vs 2), prior skeletal-related event (no vs yes), and serum alkaline phosphatase (\< upper limit of normal \[ULN\] vs ≥ ULN).

The primary objective of the study is to determine whether treatment with zoledronic acid at the time of initiation of androgen deprivation therapy for metastatic prostate cancer will delay the time to first skeletal related event. The secondary objective of the study is to compare the effect of treatment with zoledronic acid to placebo on overall survival (OS), progression-free survival (PFS) and toxicity in men receiving androgen deprivation therapy for metastatic prostate cancer.

Patients are randomized to 1 of 2 treatment arms. Treatment continues in the absence of disease progression or a skeletal-related event. All patients receive concurrent androgen deprivation therapy with a GnRH agonist. Patients also receive oral calcium and (vitamin D) supplements daily. Patients progressing to androgen-independent prostate cancer proceed to the open-label therapy with zoledronic acid IV. Treatment continues for 3 weeks in the absence of disease progression or the first skeletal-related event.

Patients are followed periodically for approximately 10 years after entry on the study.