To the Editor We read the results of the Optimize-2 trial by Hortobagyi et al1 with keen interest. After 9 or more doses of monthly zoledronic acid or pamidronate, 416 women with breast cancer with bone metastases were randomized to receive zoledronic acid once every 4 weeks (4W) or zoledronic acid once every 12 weeks (12W) for 1 year. The results showed that the 12W zoledronic acid was noninferior to 4W zoledronic acid dosing.