Ibandronate vs Pamidronate in the Treatment of Malignant Hypercalcemia

Data from the first study to compareibandronate with pamidronate (Aredia) in the treatment of malignanthypercalcemia were presented at the 37th annual meeting of the American Societyof Clinical Oncology. The results demonstrated that rates of response, time toresponse, and time to onset of lower calcium levels were similar between the twocompounds. However, in the subset of patients with severe hypercalcemia (initialserum calcium > 3.5 mmol/L), ibandronate appeared statistically superior topamidronate in restoring calcium levels to normal.

"This preliminary comparative data is an importantaddition to the body of evidence on ibandronate in the clinical setting.Patients with severe malignant hypercalcemia are at high risk of significantclinical complications; therefore, these new data are of interest to practicingoncologists," said Martin Pecherstorfer, MD, from the Wilheminspital inVienna, Austria, who presented the results.

Calcium Levels Decrease Significantly

The trial was conducted in 19 centers and enrolled 72patients with hypercalcemia of malignancy (corrected serum calcium > 2.7 mmol/L).Each patient received a single infusion of either ibandronate or pamidronate,and serum calcium levels were measured daily. Four days postinfusion, patientstreated with ibandronate showed a mean reduction in corrected serum calcium of0.73 mmol/L vs 0.57mmol/L for pamidronate. Moreover, patients with severehypercalcemia (baseline corrected serum calcium above 3.5 mmol/L, n = 11)treated with ibandronate experienced a statistically significant greater meanimprovement than those treated with pamidronate.

Among the drug-related adverse effects was an increase inbody temperature, combined with flu-like symptoms, ie, pain in muscles, bonepain, headache, pain in the extremities, hot flushes, and increased sweating.The number of adverse events and their profile did not differ between theibandronate and pamidronate groups.