Inclusion Criteria

Inclusion criteria:

- Prostate cancer with at least one cancer-related bone lesion with or without hormonal
treatment.

- Breast cancer with at least one cancer-related bone lesion

- Negative pregnancy test at screening in case of child-bearing potential and
Performance status ECOG 0-2

- Normal liver and kidney function

- Prior surgery, chemotherapy and radiotherapy is allowed. At least 4 weeks must have
elapsed since the completion of surgery, chemotherapy and radiotherapy to breast or
bone.

Exclusion criteria:

- Prior treatment with bisphosphonates within 6 months before study start, and during
treatment with zoledronic acid. Known hypersensitivity to zoledronic acid or other
bisphosphonates. Corrected (adjusted for serum albumin) serum calcium concentration <
8.0 mg/dl (2.00 mmol/L) or ≥12.0mg/dl (3.00 mmol/L)

- Current/active dental problems including

- infection of the teeth or jawbone

- dental or fixture trauma

- current or previous osteonecrosis of the jaw

- exposed bone in the mouth

- slow healing after dental procedures

- recent (within 6 weeks) or planned dental or jaw surgery (extraction, implants)

- Patients with clinically symptomatic brain metastases. Severe physical or
psychological concomitant diseases expected to impair compliance with the provisions
of the study protocol or impair the assessment of drug of patient safety

- Clinically significant ascites, NYHA III or IV, cardiac failure, clinically relevant
pathologic findings in ECG

- History of diseases with influence on bone metabolism such as Paget´s disease and
primary hyperparathyroidism and with need of treatment for osteoporosis (defined
according to DVO, T-Score ≤2.5).

- Previous radiation therapy to bone (including therapeutic radioisotopes such as
strontium 89) within 1 month

Additional protocol-defined inclusion/exclusion criteria may apply