Data from the first study to compare
ibandronate with pamidronate (Aredia) in the treatment of malignant
hypercalcemia were presented at the 37th annual meeting of the American Society
of Clinical Oncology. The results demonstrated that rates of response, time to
response, and time to onset of lower calcium levels were similar between the two
compounds. However, in the subset of patients with severe hypercalcemia (initial
serum calcium > 3.5 mmol/L), ibandronate appeared statistically superior to
pamidronate in restoring calcium levels to normal.
"This preliminary comparative data is an important
addition to the body of evidence on ibandronate in the clinical setting.
Patients with severe malignant hypercalcemia are at high risk of significant
clinical complications; therefore, these new data are of interest to practicing
oncologists," said Martin Pecherstorfer, MD, from the Wilheminspital in
Vienna, Austria, who presented the results.
Calcium Levels Decrease Significantly
The trial was conducted in 19 centers and enrolled 72
patients 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, patients
treated with ibandronate showed a mean reduction in corrected serum calcium of
0.73 mmol/L vs 0.57mmol/L for pamidronate. Moreover, patients with severe
hypercalcemia (baseline corrected serum calcium above 3.5 mmol/L, n = 11)
treated with ibandronate experienced a statistically significant greater mean
improvement than those treated with pamidronate.
Among the drug-related adverse effects was an increase in
body temperature, combined with flu-like symptoms, ie, pain in muscles, bone
pain, headache, pain in the extremities, hot flushes, and increased sweating.
The number of adverse events and their profile did not differ between the
ibandronate and pamidronate groups.