Final efficacy and safety results of an Italian, multicenter clinical trial in 312 breast cancer patients with newly diagnosed bone metastases treated with zoledronic acid

Abstract

830 Background: Zometa (zoledronic acid, Zol), a new, highly potent, heterocyclic nitrogen-containing bisphosphonate has demonstrated to significantly reduce the risk of developing skeletal related events (SREs) in a wide variety of solid tumors and multiple myeloma. Methods: In 2001 we started a multicenter, open-label, prospective clinical trial in order to describe the course over 12 months in SREs in breast cancer patients with newly diagnosed bone metastases treated with Zol 4 mg every 3 or 4 weeks via 15-min infusion, in addition to antineoplastic therapy. The main secondary objectives included: bone pain and analgesic use evaluation, quality of life and tolerability of Zol 4 mg. In the 60 participating centers, 312 patients were enrolled. Results: 29.9 % of patients reported at least one SRE. Regarding the proportion of patients with each SRE the following distribution was observed: radiation therapy to bone (22.5%), pathological non vertebral fracture (4.8 %), pathological vertebral fracture (3.5 %), spinal cord compression (2.3 %), hypercalcemia ( 1 %) and surgery to bone (0.6 %).The mean skeletal morbidity rate was 0.9 (sd: 3.8) and the median time to first SRE was not reached. 53.1 %, 23.8 % and 23.1 % of patients reported respectively a decrease, no change and an increase in BPI composite score at the end of the study. 19.3 %, 63.9 % and 16.7 % of patients reported respectively a decrease, no change and an increase in the use of analgesics at the end of the study. Pyrexia (21.5 %), bone pain (10.3%), hypocalcemia (9 %), vomiting (3.2 %), nausea (2.9 %) and asthenia (2.6 %) were the most common adverse events considered related to study drug. No renal safety concerns were observed. Conclusions: This data confirms Zol as an effective and safe therapeutic option for breast cancer patients with newly diagnosed bone metastases. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Novartis Novartis Novartis