Zoledronic Acid Group Research Articles

Randomized Controlled Trial of Zoledronic Acid to Prevent Bone Loss in Men Receiving Androgen Deprivation Therapy for Nonmetastatic Prostate Cancer

A multicenter double-blind, randomized, placebo controlled clinical trial was performed to assess the effect of zoledronic acid, a potent new bisphosphonate, on bone mineral density during androgen deprivation therapy for nonmetastatic prostate cancer. Men with M0 (no distant metastases) prostate cancer beginning androgen deprivation therapy were randomly assigned to receive 4 mg. zoledronic acid or placebo intravenously every 3 months for 1 year. The primary efficacy variable was the percent change from baseline to 1 year in bone mineral density of the lumbar spine as measured by dual energy x-ray absorptiometry. A total of 106 men were enrolled in the trial. Mean bone mineral density in the lumbar spine increased by 5.6% in men receiving zoledronic acid and decreased by 2.2% in those given placebo (mean difference 7.8%, 95% confidence interval 5.6%-10.0%, p <0.001). Mean bone mineral density of the femoral neck, trochanter and total hip also increased in the zoledronic acid group and decreased in the placebo group. Zoledronic acid was well tolerated. Zoledronic acid increases bone mineral density in the hip and spine during androgen deprivation therapy for nonmetastatic prostate cancer.

Zoledronic acid to prevent bone loss in the first 6 months after renal transplantation

Bisphosphonates can prevent bone mineral density loss after renal transplantation, but their effect on trabecular mineralization and bone morphology, two key factors of bone stability, remains unknown. In a 6-month, randomized, placebo-controlled study, 20 kidney transplant recipients received either 4 mg zoledronic acid or placebo twice within 3 months after engraftment. At transplantation and after 6 months, mean trabecular calcium concentration and trabecular morphometry were measured in bone biopsies. Bone mineral density (BMD) of the femoral neck and the lumbar spine were evaluated by dual-energy x-ray absorptiometry, and serum biochemical markers of bone metabolism were determined monthly. Trabecular calcium content increased significantly in the zoledronic acid group, but remained unchanged in the placebo group. BMD at femoral neck showed no change in the zoledronic acid group, but decreased in the placebo group. BMD of the lumbar spine was increased in the zoledronic acid group without change in the placebo group. High-turnover bone disease resolved similarly in both groups, as evidenced by a significant decrease of eroded bone surface, osteoclast and osteoblast surface. Serologic markers of bone formation and resorption were significantly lower in zoledronic acid-treated patients throughout the study. Kidney transplant function was stable after zoledronic acid therapy. Our results show that administration of zoledronic acid improves the calcium content of cancellous bone after kidney transplantation. The beneficial effect of bisphosphonate therapy is further evidenced by an increase of lumbar spine BMD, and stabilization of femur BMD.

Therapeutic Use of Bisphosphonates in Breast Cancer

Bisphosphonates are synthetic derivatives of phosphonate, a normal constituent of bone. These agents are potent inhibitors of osteoclastic resorption, and as such are being explored for the management of various pathological conditions including osteoporosis, hypercalcemia, bone metastases and certain aspects of cancer. Among the first agents to be developed in the class, clodronic acid has shown conflicting results with respect to its ability to reduce osseous metastases, while pamidronic acid reduced hypercalcemia effectively compared with placebo in patients with breast cancer and multiple myeloma. Recent exploratory studies have shown that the novel bisphosphonate zoledronic acid reduces hypercalcemia more effectively than pamidronic acid in patients with various malignancies. In a recent phase III trial designed to show equivalence, zoledronic acid was as effective as pamidronic acid in the number of skeletal-related events arising over a predefined period of time. Furthermore, a trend in radiation therapy delay was observed in the zoledronic acid group. Zoledronic acid appears to be an effective agent in reducing the complications from bone involvement in cancer patients and it has shown efficacy in the prevention of osteoporosis in healthy postmenopausal women. For these reasons, it is being investigated as an adjunct to adjuvant therapy for postmenopausal patients with early breast cancer treated with nonsteroidal aromatase inhibitors, because efficient and prolonged estrogen deprivation with the latter agents may result in an increased risk of bone degradation in some patients.

Zoledronic acid in cancer patients with bone metastases: Results of phase I and II trials

Zoledronic acid (Zometa, Novartis Pharmaceuticals Corp, East Hanover, NJ) is a new, highly potent bisphosphonate that may provide improved management of skeletal complications in cancer patients with bone metastases. A total of 383 cancer patients with osteolytic bone lesions was evaluated in two phase I studies and one phase II study of zoledronic acid. The phase I studies used two dosing regimens, either a 5-minute monthly intravenous infusion of 0.1 to 8 mg administered for 3 or more months or a single 30 to 60 second intravenous bolus of 1 to 16 mg. Zoledronic acid was well tolerated in the two phase I studies and a maximum tolerated dose was not reached in either study. A dose-dependent decrease in urinary markers of bone resorption was observed with the monthly 5-minute infusion. A single intravenous bolus of doses ranging from 2 to 16 mg zoledronic acid suppressed biochemical markers of bone resorption for up to 8 weeks. The phase II study evaluated a 5-minute infusion of 0.4, 2, or 4 mg zoledronic acid and a 2-hour infusion of 90 mg pamidronate in 280 patients with bone metastases and multiple myeloma or breast cancer. Significantly fewer patients receiving the 2 and 4 mg doses of zoledronic acid or 90 mg pamidronate required radiation therapy to bone than those patients receiving a 0.4 mg dose of zoledronic acid. Only 30% to 35% of patients in the 2 and 4 mg zoledronic acid groups or in the pamidronate group experienced any skeletal related event compared with 46% in the 0.4 mg zoledronic acid group. Adverse events consistent with an acute phase reaction were observed with both bisphosphonates. No new, unexpected adverse events were observed with this novel bisphosphonate. These studies support the further evaluation of zoledronic acid in cancer patients with osteolytic metastases. Doses of 0.4 mg or less are ineffective, while rapid infusion of more than 8 mg may increase the risk of renal dysfunction. A 4 mg dose given as a brief infusion appears to offer an excellent benefit/risk ratio for further evaluation in phase III trials.

Zoledronic acid in the treatment of hypercalcemia of malignancy: Results of the international clinical development program

This report summarizes results of the clinical development program evaluating zoledronic acid (Zometa; Novartis Pharmaceuticals Corp, East Hanover, NJ) in the treatment of hypercalcemia of malignancy (HCM). In addition to a phase I dose escalation trial, two randomized, double-blind, double-dummy studies were conducted in parallel to investigate the clinical efficacy and safety of 4 mg and 8 mg zoledronic acid in patients with moderate to severe HCM. Patients were treated with a single dose of zoledronic acid (4 or 8 mg) via 5-minute infusion or a control treatment, 90 mg pamidronate via 2-hour infusion. Patients who relapsed or had refractory HCM after initial treatment could be re-treated with 8 mg zoledronic acid. End points included rate of complete response, defined as normalization of corrected serum calcium by day 10, change in corrected serum calcium, time to relapse, duration of response, and bone biochemical markers. Doses of ≥0.02 mg/kg were effective and nontoxic in the phase I study. In the controlled studies, 287 patients were randomized and evaluated for safety and 275 patients were evaluable for efficacy. The proportions of patients with a complete response by day 10 were 88.4% and 86.7% in the 4 mg and 8 mg zoledronic acid groups, respectively, compared with 69.7% in the 90 mg pamidronate group. Corrected serum calcium normalization occurred by day 4 in 45.3% of patients treated with 4 mg zoledronic acid, 55.6% of patients treated with 8 mg zoledronic acid, and 33.3% of patients treated with pamidronate. Mean change from baseline in corrected serum calcium also was greater with zoledronic acid than with pamidronate. Median times to relapse were significantly longer in both the zoledronic acid 4 mg and 8 mg groups compared with the pamidronate group. There were no significant differences in efficacy between the 4 mg and 8 mg zoledronic acid doses. Retreatment in 69 patients with relapsing or refractory hypercalcemia with 8 mg zoledronic acid resulted in a 52% complete response rate. Fever, hypophosphatemia, and asymptomatic hypocalcemia were the most common drug-related adverse events. These studies have shown that a short single intravenous dose of 4 mg or 8 mg zoledronic acid is effective in treating moderate to severe HCM. Zoledronic acid produced a higher rate of calcium normalization, faster onset of action, and longer time to relapse than pamidronate, while maintaining an excellent safety profile. The lower dose of 4 mg is recommended as initial therapy, with the 8 mg dose reserved for patients requiring retreatment.