Bone pain reduction in patients with metastatic breast cancer treated with ibandronate-results from a post-marketing surveillance study.

BACKGROUND: Pain relief is an important treatment goal for breast cancer patients with metastatic bone disease and treatment should be associated with a low rate of side effects. This interim analysis of a prospective non-interventional study documents the efficacy and safety of the amino-bisphosphonate ibandronate in the treatment of metastatic bone disease under real-life conditions.

PATIENTS AND METHODS: For up to 24 weeks 913 breast cancer patients received IV infusions of 6 mg ibandronate every 3-4 weeks or 50 mg of oral ibandronate once daily. Efficacy variables included pain severity, analgesic use, and skeletal-related events; the major safety parameter was renal function, assessed by serum creatinine levels. Subgroup analyses were performed according to pretreatment with bisphosphonates (none, ibandronate, or other bisphosphonates).

RESULTS: At baseline, patients with ibandronate pretreatment tended to have lower mean pain scores and lower serum creatinine levels than those pre-treated with other bisphosphonates. Over the observation period, analgesic use did not increase. Among the 712 patients reporting pain at baseline, 70% achieved an improvement in pain severity during treatment with ibandronate, and there was no evidence to suggest relevant differences in mean pain reductions with IV or oral administration of ibandronate or according to prior bisphosphonate treatment. Skeletal-related events were rare (7%). Changes in serum creatinine levels during ibandronate treatment were small and both formulations of ibandronate were rated as well tolerated by physicians and patients.

CONCLUSIONS: Data from this non-interventional study confirm the analgesic efficacy and safety profile of IV and oral ibandronate under real-life conditions.