Continued suppression of bone turnover following a single dose of zoledronic acid: Time to re-think dosing intervals in the management of bone metastases?

9111 Background: The management of patients (pts) with bone metastases has changed significantly over the past decade, with the advent of newer, more potent anti-osteoclastic agents. However, the dosing interval in which these agents are given has not changed; pts are still dosed at a frequency of monthly or q3weekly injections. It is not known if this is the optimal dosing frequency or due to convention. The purpose of this study was to determine the duration of suppression of bone turnover by Zoledronic Acid (ZA) in a population of bisphosphonate naive metastatic breast cancer (MBC) pts. Methods: This prospective single arm phase II study enrolled 26 pts with MBC to bone who had not received bisphosphonates in the metastatic setting. A single dose of ZA was given at week 0, and biomarkers of bone turnover (serum CTX) were collected every 2 weeks subsequently. Pain scores and quality of life data were collected every 4 weeks. Pts remained on study if their biomarkers remained suppressed, but came off stu...