ROCKVILLE, Maryland—Zometa (zoledronic acid for injection) has received marketing approval from the US Food and Drug Administration for the treatment of hypercalcemia of malignancy. Zoledronic acid(Drug information on zoledronic acid) represents a new generation of intravenous bisphosphonates. It is currently approved for treating hypercalcemia of malignancy in more than 30 countries.
Novartis has also filed an application with the FDA seeking approval for the drug in treating bone metastases that occur as a result of a number of cancers. These malignancies include prostate and lung cancer, for which no bisphosphonate therapy is currently approved.
Hypercalcemia of malignancy is the most common life-threatening metabolic complication associated with cancer, Novartis noted. Excessively high calcium levels—which result when factors produced by tumor cells overstimulate osteoclasts—affect more than 10% of cancer patients, generally in the late stages of their disease.
Zoledronic acid inhibits increased osteoclastic activity and the release of skeletal calcium. If hypercalcemia of malignancy recurs, patients can be treated again with the same zoledronic acid protocol.
The company submitted two pivotal studies comparing the drug with pamidronate(Drug information on pamidronate) disodium for injection (Aredia), the current treatment standard for hypercalcemia of malignancy.
The two international, multicenter trials enrolled a total of 287 patients (275 evaluable). Patients were infused with a single dose of zoledronic acid, at either 4 mg or 8 mg, or a single 90-mg dose of pamidronate delivered over 2 hours. Researchers measured clinical response by the normalization of corrected serum calcium by day 10.
Pooled results of the two studies showed that by day 10, 88% of the patients who received zoledronic acid 4 mg had normal corrected serum calcium concentrations, compared with 70% of those treated with pamidronate (P = .002).
