Renal safety of intravenous ibandronic Acid in breast cancer patients with metastatic bone disease.

BACKGROUND

Renal adverse events are a troublesome complication of bisphosphonate therapy. This study investigated the effect of intravenous ibandronic acid (ibandronate) treatment on renal function in breast cancer patients with metastatic bone disease.

METHODS

74 patients were randomised to double-blind (but not dose-blind) treatment with bolus injections of ibandronic acid 2mg (n = 23), 1-hour infusions of ibandronic acid 6mg (n = 28), or placebo injections or infusions (n = 23). According to randomisation, patients received either three injections or three infusions over the 3-month period, one at the start and two subsequent doses at 4-weekly intervals. Measurements of urinary excretion of total protein, albumin, alpha(1)-microglobulin, N-acetyl-beta-D-glucosaminidase, haematuria and serum creatinine were performed before, during and after treatment.

RESULTS

Treatment with ibandronic acid was not associated with impairment of renal function; the renal safety profiles of ibandronic acid 2 and 6mg were similar to that of placebo. Assessments of proteinuria, haematuria, enzymuria and serum creatinine indicated that there were no statistically significant changes between pre- and post-treatment levels in patients receiving ibandronic acid 2 or 6mg or between patients receiving ibandronic acid or placebo. Urine parameters varied during treatment in the same range with approximately similar frequency in the ibandronic acid and placebo groups.

CONCLUSIONS

Short-term administration of intravenous ibandronic acid did not impair renal function in breast cancer patients with metastatic bone disease. Because tolerability profiles vary between bisphosphonates, the lack of renal toxicity with ibandronic acid makes the drug an attractive treatment option for metastatic bone disease.