Zoledronic acid treatment for cancerous bone metastases: A phase IV study in Taiwan

Aim of study: To investigate the features, adverse effects, bone marker changes in patients with breast cancer, prostate cancer, and multiple myeloma with bone metastases under Zometa® therapy. Materials and Methods: This post-marketing study included 414 Taiwanese patients with bone metastases secondary to breast cancer, prostate cancer, or multiple myeloma who received Zometa^® for 48 weeks. The patients′ characteristics, medication and adverse events were recorded, meanwhile changes in four serum bone metabolic markers and pain reduction were assessed every three months for one year. Results: A total of 3,711 doses of Zometa^® were infused, accounting for 294.5 patient-years. Adverse events occurred in 9.4% of patients, with bone pain, insomnia, constipation, and pyrexia as the most frequently reported. There was no osteonecrosis of the jaw. The incidence of skeletal-related events decreased significantly from 44.9% to 18.8%. Serum NTx, BAP, and TRACP5b steadily decreased to nadir at six months, but serum OPG was persistently elevated until the end of one year. The average decrease in pain score was 14.1, 14.3, and 16.7 for prostate cancer, breast cancer, and multiple myeloma patients, respectively. Conclusion: Zometa^® can be safely administered in Taiwanese patients with bone metastases secondary to breast cancer, prostate cancer, and multiple myeloma. There are concomitant decreases in skeletal-related events and bone pain.