Efficacy and safety of ibandronate in the treatment of hypercalcemia of malignancy: a randomized multicentric comparison to pamidronate.
OBJECTIVE
To compare the efficacy and safety of ibandronate and pamidronate in patients with hypercalcemia of malignancy (HCM).


METHODS
Seventy-two patients with HCM [albumin-corrected serum calcium (CSC) >2.7 mmol/l] were treated with a single infusion of ibandronate (2 or 4 mg) or pamidronate (15, 30, 60, or 90 mg) on day 0. The dose was dependent on the severity of hypercalcemia (baseline CSC level). CSC was assessed daily until day 4, then at intervals until day 28. The primary endpoint was lowering of CSC at day 4. Secondary endpoints included the number of patients responding and time to re-increase following response.


RESULTS
Using the CSC baseline approach, the most frequently administered doses were 4 mg ibandronate (78.4%) and 60 mg pamidronate (50.0%). Mean lowering of CSC at day 4 was 0.6 mmol/l for ibandronate and 0.41 mmol/l for pamidronate. The 95% confidence interval for the difference ibandronate pamidronate had a lower limit of 0.05 mmol/l, indicating that ibandronate was as effective as pamidronate. The number of patients responding to the two agents was also similar; 76.5% of ibandronate patients and 75.8% of pamidronate patients were rated as responders after the first dose of study medication. The median time to re-increase after response was longer for ibandronate (14 days) than pamidronate (4 days) ( P=0.0303). In the subgroup of 17 patients with high baseline CSC (>3.5 mmol/l), ibandronate appeared to be more effective than pamidronate. The safety profile of both agents was similar.


CONCLUSIONS
Ibandronate is at least as effective as pamidronate in the treatment of HCM. Furthermore, in patients with higher baseline CSC ibandronate appears to be more effective than pamidronate. The duration of response is significantly longer with ibandronate than pamidronate.
Pecherstorfer
M
M
First Department of Medicine and Oncology, Wilhelminenspital, Montleartstrasse 37, 1171, Vienna, Austria. martin.pecherstorfer@1me.wil.magwien.gv.at
Steinhauer
E U
EU
Rizzoli
R
R
Wetterwald
M
M
Bergström
B
B
D000284:Administration, Oral; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology*; D001862:Bone Resorption; D004164:Diphosphonates / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000188:drug therapy* / Q000209:etiology*; D000077557:Ibandronic Acid; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D000077268:Pamidronate; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D004164:Diphosphonates; D000077268:Pamidronate; D000077557:Ibandronic Acid