Ibandronate is effective in preventing skeletal events in patients with bone metastases secondary to colorectal carcinoma

Abstract

3639 Background: Patients with metastatic colorectal carcinoma (CRC) often develop metastases to bone with a high risk of complications. Methods: A randomized, placebo-controlled trial was conducted to evaluate the efficacy and safety of ibandronate in patients with bone metastases from CRC. The primary efficacy endpoint was proportion of patients with skeletal related events (defined as pathologic fracture, spinal cord compression, radiation therapy to bone, change in antineoplastic therapy and surgery to bone). Secondary endpoints included time to first skeletal event, skeletal morbidity rate (events/year) and time to progression of bone lesions. Results: In 30 patients with CRC, treatment with intravenous ibandronate 6mg over a15-minute infusion significantly reduced the proportion of patients with skeletal events (39% versus 78% with placebo; p=0.019) and prolonged the time to first event by at least 6 months (median >279 versus 93 days with placebo; p=0.009). Ibandronate also significantly reduced the skeletal morbidity rate (mean 2.36 versus 3.14 with placebo; p=0.018) and prolonged time to progression of bone lesions (214 days versus 81 days with placebo; p=0.018). Ibandronate was well tolerated with very rare grade 3 or 4 toxicity. The incidence of renal adverse events was comparable to placebo and there were no clinically-relevant changes of serum creatinine. Conclusion: Ibandronate provided significant clinical benefit in patients with bone metastases secondary to CRC. This small pilot study suggests a role for ibandronate in metastatic bone disease from colorectal carcinoma. Larger confirmatory studies are required. No significant financial relationships to disclose.