A Study to Evaluate the Efficacy and Tolerability of Zoledronic Acid in Patients With Metastatic Prostate Cancer Who Can be Treated With a Group of Medications Known as Bisphosphonates

Inclusion Criteria: * Written informed consent must be obtained * Age \> 18 years * Histologically confirmed diagnosis of carcinoma of the prostate * Current (or previous) objective evidence of metastatic disease to the bone * Currently receiving 1st line hormonal therapy with LHRH agonists or other hormonal treatments * ECOG performance status of 0, 1, or 2 Exclusion Criteria: * Patients with abnormal renal function as evidenced by either a serum creatinine determination 1.5 x or greater above the upper limit of normal or by a calculated creatinine clearance of 60 ml/minute or less * Corrected (adjusted for serum albumin) serum calcium concentration \< 8.0 mg/dl (2.00 mmol/L) * WBC\<3.0x1'000'000'000, ANC \< 1500/mm3, Hgb\<8.0 g/dL, platelets \< 75 x 1'000'000'000/L. * Liver function tests \>2.5 ULN, serum creatinine \>1.5 ULN. * Patients with another nonmalignant disease which would confound the evaluation of primary endpoints or prevent the patient complying with the protocol. * Known hypersensitivity to zoledronic acid or other bisphosphonates * Subjects who, in the opinion of the investigator, are unlikely to cooperate fully during the study Other protocol-defined inclusion / exclusion criteria apply.