ABSTRACT: Hypercalcemia of malignancy is a serious complication of cancer. The objective of this study was to investigate the efficacy and safety of zoledronic acid, a new-generation bisphosphonate and the most potent inhibitor of bone resorption identified to date, for hypercalcemia of malignancy in Japanese patients.
Patients with hypercalcemia of malignancy, defined as an albumin-corrected serum calcium level > or =12.0 mg/dl, were treated with a single dose of zoledronic acid, 4 mg, by 15 min infusion. Clinical end-points included the proportion of patients with complete response, which was defined as a decrease of corrected serum calcium < or =10.8 mg/dl by day 10, and time to relapse, which is defined as the duration in days between the date of infusion and last available corrected serum calcium <11.6 mg/dl.
Twenty-seven patients were enrolled in this study and 25 patients were evaluable for the efficacy of zoledronic acid. The mean corrected serum calcium level decreased from 14.5 to 9.6 mg/dl by day 10. The complete response rate was 84%. The median time to relapse was 23 days, ranging from 0 to 56 days. The most frequently observed adverse event was fever (< or =38 degrees C). Electrolyte abnormalities suspected to be drug related including grade 3 or 4 hypocalcemia, hypophosphatemia and hypokalemia were observed in 11 patients; however, all patients were asymptomatic. No serious adverse events associated with renal toxicity were reported.
Zoledronic acid is well tolerated and is effective for hypercalcemia of malignancy in Japanese patients.
Japanese Journal of Clinical Oncology 02/2005; 35(1):28-33. · 1.78 Impact Factor