Zoledronic acid versus pamidronate in the treatment of skeletal metastases in patients with breast cancer or osteolytic lesions of multiple myeloma: a phase III, double-blind, comparative trial.

PURPOSE: Zoledronic acid, a new and more potent bisphosphonate, was compared with pamidronate, the current standard treatment for patients with osteolytic or mixed bone metastases/lesions. PATIENTS AND METHODS: A total of 1,648 patients with either Durie-Salmon stage III multiple myeloma or advanced breast cancer and at least one bone lesion were randomly assigned to treatment with either 4 or 8 mg of zoledronic acid via 15-minute intravenous infusion or 90 mg of pamidronate via 2-hour intravenous infusion every 3 to 4 weeks for 12 months. The primary efficacy endpoint was the proportion of patients experiencing at least one skeletal-related event over 13 months. RESULTS: The proportion of patients with at least one skeletal-related event was similar in all treatment groups. Median time to the first skeletal-related eventwas approximately 1 year in each treatment group. The skeletal morbidity rate was slightly lower in patients treated with zoledronic acid than in those treated with pamidronate, and zoledronic acid (4 mg) significantly decreased the incidence and event rate for radiation therapy to bone, both overall and in breast cancer patients receiving hormonal therapy. Pain scores decreased in all treatment groups in the presence of stable or decreased analgesic use. Zoledronic acid (4 mg) and pamidronate were equally well tolerated; the most common adverse events were bone pain, nausea, fatigue, and fever and < 5% of serious adverse events were related to the study drug. The incidence of renal impairment among patients treated with 4 mg of zoledronic acid via 15-minute infusion was similar to that among patients treated with pamidronate. CONCLUSIONS: Zoledronic acid (4 mg) via 15-minute intravenous infusion was as effective and well tolerated as 90 mg of pamidronate in the treatment of osteolytic and mixed bone metastases/lesions in patients with advanced breast cancer or multiple myeloma. (Can-

Pamidronate prevents skeletal complications and is effective palliative treatment in women with breast carcinoma and osteolytic bone metastases: long term follow-up of two randomized, placebo-controlled trials.

BACKGROUND: Pamidronate therapy previously has been shown to reduce skeletal complications effectively for up to 12 months in breast carcinoma patients with bone metastases. The current study data provide further follow-up results regarding the effects of long term (up to 24 months) pamidronate treatment in women with breast carcinoma and osteolytic metastases. METHODS: Follow-up results from two prospective, multicenter, randomized, double-blind, placebo-controlled intervention trials conducted at academic and community oncology centers were combined to provide a large data set with which to evaluate the long term efficacy and safety of pamidronate therapy. Seven hundred fifty-four women with Stage IV breast carcinoma and osteolytic metastases were randomized to the 2 treatment arms of the trial. Three patients were excluded from the intent-to-treat population for the analysis. A total of 751 evaluable patients were randomized to receive either a 90-mg intravenous pamidronate infusion (367 patients) or a placebo infusion (384 patients) every 3-4 weeks. The primary outcome measures were skeletal morbidity rate (events/year), proportion of patients developing a skeletal complication, and time to first skeletal complication. RESULTS: Of the 367 women receiving pamidronate, 115 (31.3%) completed the trial and 81 (22.1%) discontinued the study due to adverse events. Of the 384 women who received placebo, 100 (26.0%) completed the study and 76 (19.8%) discontinued the study due to adverse events. The skeletal morbidity rate was 2.4 in the pamidronate group and 3.7 in the placebo group (P < 0.001). In the pamidronate group, 186 of the 367 patients (51%) had skeletal complications compared with 246 of the 384 patients in the placebo group (64%) (P < 0.001). The median time to first skeletal complication was 12.7 months in the pamidronate group and 7 months in the placebo group (P < 0.001). Six patients treated with pamidronate discontinued treatment due to drug-related adverse events. Pain and analgesic scores were significantly worse in the placebo group compared with those patients in the pamidronate group. CONCLUSIONS: In the current study, monthly infusions of 90 mg of pamidronate as a supplement to antineoplastic therapy were found to be well tolerated and superior to antineoplastic therapy alone in preventing skeletal complications and palliating symptoms for at least 24 months in breast carcinoma patients with osteolytic bone metastases.

Pamidronate reduces skeletal morbidity in women with advanced breast cancer and lytic bone lesions: a randomized, placebo-controlled trial. Protocol 18 Aredia Breast Cancer Study Group.

PURPOSE: To assess whether pamidronate can reduce the frequency of skeletal morbidity in women with lytic bone metastases from breast cancer treated with hormone therapy. PATIENTS AND METHODS: Three hundred seventy-two women with breast cancer who had at least one lytic bone lesion and who were receiving hormonal therapy were randomized to receive 90 mg of pamidronate or placebo as a 2-hour intravenous infusion given in double-blind fashion every 4 weeks for 24 cycles. Patients were evaluated for skeletal complications: pathologic fractures, spinal cord compression, irradiation of or surgery on bone, or hypercalcemia. The skeletal morbidity rate (the ratio of the number of skeletal complications to the time on trial) was the primary efficacy variable. Bone pain, use of analgesics, quality of life, performance status, bone tumor response, and biochemical parameters were also evaluated. RESULTS: One hundred eighty-two patients who received pamidronate and 189 who received placebo were assessable. The skeletal morbidity rate was significantly reduced at 12, 18, and 24 cycles in patients treated with 90 mg of pamidronate (P = .028, .023, and .008, respectively). At 24 cycles, the proportion of patients having had any skeletal complication was 56% in the pamidronate group and 67% in the placebo group (P = .027). The time to the first skeletal complication was longer for patients receiving pamidronate than for those given placebo (P = .049). There was no statistical difference in survival or in objective bone response rate. Pamidronate was well tolerated. CONCLUSION: Treatment with 90 mg of pamidronate as a 2-hour intravenous infusion every 4 weeks in addition to hormonal therapy significantly reduces skeletal morbidity from osteolytic metastases.

Long-term prevention of skeletal complications of metastatic breast cancer with pamidronate. Protocol 19 Aredia Breast Cancer Study Group.

PURPOSE: Pamidronate, an aminobisphosphonate, has been shown to lower the risk of skeletal complications associated with lytic bone lesions for up to 1 year in women with stage IV breast cancer who received chemotherapy. We studied the long-term effectiveness and safety of continued treatment with intravenous pamidronate infusions for up to 2 years. PATIENTS AND METHODS: Three hundred eighty-two women with metastatic breast cancer and lytic bone lesions who received chemotherapy were randomly assigned to receive either 90 mg of pamidronate or placebo intravenously every 3 to 4 weeks in this double-blind, multicenter, parallel-group trial. Patients were evaluated monthly for 2 years for skeletal complications, which included pathologic fractures, need for radiation or surgery to treat bone complications, spinal cord compression, and hypercalcemia. Bone pain, analgesic use, bone biochemical markers, performance status, quality of life, radiologic response in bone, and survival were also evaluated. RESULTS: As in the first year of treatment, the proportion of patients with any skeletal complication was significantly less for the pamidronate than the placebo group at 15, 18, 21, and 24 months (P < .001). The proportions of patients with any pathologic fracture (i.e., vertebral and nonvertebral fractures), need for radiation or surgery to treat bone complications, and hypercalcemia were also statistically less for the pamidronate than the placebo group. The median time to the first skeletal complication was 13.9 months in the pamidronate-treated women and 7.0 months in the placebo group (P < .001). Long-term treatment did not result in any unexpected adverse events. Survival did not differ between the two groups. CONCLUSION: The risk for osteolytic bone lesion complications in metastatic breast cancer was significantly decreased with monthly infusions of 90 mg of pamidronate, and this effect was maintained for at least 2 years. Pamidronate is a useful adjunct to standard chemotherapy in the palliative treatment of metastatic breast cancer.

Long-term pamidronate treatment of advanced multiple myeloma patients reduces skeletal events. Myeloma Aredia Study Group.

PURPOSE: To determine the efficacy and safety of 21 monthly cycles of pamidronate therapy in patients with advanced multiple myeloma. PATIENTS AND METHODS: Patients with stage III myeloma and at least one lytic lesion received either placebo or pamidronate 90 mg intravenously administered as a 4-hour infusion monthly for 21 cycles. At study entry, the patients were stratified according to whether they were to receive first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy. Skeletal events (pathologic fracture, radiation or surgery to bone, and spinal cord compression) and hypercalcemia were assessed monthly. RESULTS: The results of the first nine previously reported cycles are extended to 21 cycles. Of the 392 randomized patients, efficacy could be evaluated in 198 who received pamidronate and 179 who received placebo. After 21 cycles, the proportion of patients who developed any skeletal event was lower in the pamidronate-group (P = .015). The mean number of skeletal events per year was less in the pamidronate-group (1.3) than in placebo-treated patients (2.2; P = .008). Although survival was not different between the pamidronate-treated group and placebo patients overall, stratum 2 patients who received pamidronate lived longer than those who received placebo (14 v 21 months, P = .041). Pamidronate was safe and well tolerated during the 21 cycles of therapy. CONCLUSION: Long-term monthly infusions of pamidronate as an adjunct to chemotherapy are superior to chemotherapy alone in reducing skeletal events in stage III multiple myeloma patients, and may improve the survival of patients on salvage therapy.

Efficacy of pamidronate in reducing skeletal events in patients with advanced multiple myeloma. Myeloma Aredia Study Group.

BACKGROUND: Skeletal complications are a major clinical manifestation of multiple myeloma. These complications are caused by soluble factors that stimulate osteoclasts to resorb bone. Bisphosphonates such as pamidronate inhibit osteoclastic activity and reduce bone resorption. METHODS: Patients with stage III multiple myeloma and at least one lytic lesion received either placebo or pamidronate (90 mg) as a four-hour intravenous infusion given every four weeks for nine cycles in addition to antimyeloma therapy. The patients were stratified according to whether they were receiving first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy at entry into the study. Skeletal events (pathologic fracture, irradiation of or surgery on bone, and spinal cord compression), hypercalcemia (symptoms or a serum calcium concentration > or = 12 mg per deciliter [3.0 mmol per liter]), bone pain, analgesic-drug use, performance status, and quality of life were assessed monthly. RESULTS: Among 392 treated patients, the efficacy of treatment could be evaluated in 196 who received pamidronate and 181 who received placebo. The proportion of patients who had any skeletal events was significantly lower in the pamidronate group (24 percent) than in the placebo group (41 percent, P < 0.001), and the reduction was evident in both stratum 1 (P = 0.04) and stratum 2 (P = 0.004). The patients who received pamidronate had significant decreases in bone pain and no deterioration in performance status and quality of life. Pamidronate was tolerated well. CONCLUSIONS: Monthly infusions of pamidronate provide significant protection against skeletal complications and improve the quality of life of patients with stage III multiple myeloma.