A Prospective, Randomized, Double-blind, Stratified, Multi-center, 2-arm Trial of the Continued Efficacy and Safety of Zoledronic Acid (Every 4 Weeks vs. Every 12 Weeks) in Patients With Documented Bone Metastases From Breast Cancer

Inclusion Criteria:

- Female patients ≥ 18 years of age

- Confirmed breast cancer with bone metastasis.

- Pretreated with Zometa®, or Aredia (pamidronate) or all sequential regimens of both,
for a minimum of 9 doses.

Exclusion Criteria:

- Abnormal kidney function determined by serum creatinine levels.

- Current active dental problems including: ongoing infection of the teeth or jawbone;
current exposed bone in the mouth; and current or prior diagnosis of osteonecrosis of
the jaw.

- Recent (within 8 weeks) or planned dental or jaw surgery (e.g., extraction, implants)

- Diagnosis of metabolic bone disease other than osteoporosis (e.g., Paget's disease of
bone)

- Known hypersensitivity to Zometa

- Treatment with other investigational drugs within 30 days prior to randomization.

Other protocol-defined exclusion criteria may apply.