Recently, studies have also demonstrated the clinical benefit of oral ibandronate in preventing skeletal complications in breast cancer patients with bone metastases. Pooled results from two randomized studies involving 564 patients demonstrated that oral ibandronate (50mg/day for 96 weeks) significantly reduced the SMPR compared with placebo (p=0.004).¹⁴

However, it did not significantly reduce the percentage of patients with a new bone event, significantly delay the time to first bone event, or significantly reduce the number of skeletal fractures. Moreover, the percentage of patients reporting a GI adverse event (including dyspepsia, nausea, abdominal pain, and esophagitis) was higher in patients treated with oral ibandronate compared with placebo (14.6% versus 7.6% for placebo). Additionally, pain assessments demonstrated that oral ibandronate was effective for palliation of bone pain throughout the course of the study. At last evaluation, ibandronate significantly reduced mean pain scores (assessed on a 5-point scale) from baseline compared with increased pain scores in patients receiving placebo (p=0.001 versus placebo).²⁶ Of note, although both IV and oral ibandronate have demonstrated some clinical benefit in breast cancer patients with bone metastases, neither agent has been directly compared with IV pamidronate or zoledronic acid. Furthermore, IV and oral ibandronate have never been directly compared with each other. In order to assess the clinical benefit of these agents, these comparisons are needed.^27,28