Wolters Kluwer Health | Adis, Auckland, New Zealand. demail@adis.co.nz

Zoledronic acid (Zometa is a third-generation nitrogen-containing parenteral bisphosphonate indicated for the treatment of bone metastases due to solid tumours or multiple myeloma and for hypercalcaemia of malignancy (HCM). In patients with advanced breast or prostate cancer, zoledronic acid 4 mg every 3-4 weeks for up to 15 months significantly reduced the proportion of patients with > or =1 skeletal-related event (SRE), excluding HCM, compared with placebo. In patients with advanced breast cancer or multiple myeloma, the incidence of SREs was similar in patients treated with zoledronic acid 4 mg or pamidronic acid 90 mg every 3-4 weeks for up to 25 months but, in breast cancer patients, zoledronic acid reduced the risk of SREs, including HCM, by an additional 20% compared with pamidronic acid.In modelled cost-utility studies comparing direct costs based on efficacy and resource-use data from these and/or other trials, results have varied. In the most recent study performed from the perspective of the UK NHS and modelled over a 10-year treatment period in women with advanced breast cancer, intravenous zoledronic acid and oral ibandronic acid were dominant over no treatment. Intravenous zoledronic acid was the most cost effective, in terms of incremental costs per QALY gained, followed by oral ibandronic acid, intravenous pamidronic acid and intravenous ibandronic acid. Two other modelled analyses in patients with advanced breast cancer, also conducted from the perspective of the NHS, evaluated the cost utility of three bisphosphonate therapies in patients receiving hormonal therapy or intravenous chemotherapy. Analyses were modelled over 14.3 months (i.e. expected survival) and assumptions varied markedly from results in clinical breast cancer trials. Also, efficacy assumptions for zoledronic acid were not based on clinical trials with the drug. The results of these analyses suggest that oral ibandronic acid is more cost effective than intravenous zoledronic acid and intravenous pamidronic acid in terms of incremental cost per QALY gained. In a global, 15-month modelled cost-effectiveness analysis of patients with advanced prostate cancer, conducted from a third-party perspective, the incremental cost per QALY gained for zoledronic acid versus no treatment was $US159 200 (year 2000 value), which is about 3-fold greater than commonly accepted thresholds for cost effectiveness.In conclusion, a recent modelled economic analysis suggests that intravenous zoledronic acid 4 mg is dominant relative to no treatment in the management of bone metastases in patients with advanced breast cancer. In contrast, in patients with advanced prostate cancer, the incremental cost per QALY gained for zoledronic acid 4 mg versus no treatment was predicted to be higher than commonly accepted thresholds. Compared with other bisphosphonates in the setting of advanced breast cancer, intravenous zoledronic acid was more cost effective than oral or intravenous ibandronic acid and intravenous pamidronic acid in one study, but less cost effective than oral ibandronic acid in another. Further efficacy and economic data comparing intravenous zoledronic acid with oral ibandronic acid are needed. Meanwhile, zoledronic acid appears to be the most cost effective intravenous bisphosphonate for the management of bone metastases in patients with advanced breast cancer and possibly in patients with different types of advanced solid tumours.

PMID: 18282018 [PubMed - indexed for MEDLINE]

1: Oncologist. 2008 May;13(5):503-14. Links

Integrated analysis of zoledronic acid for prevention of aromatase inhibitor-associated bone loss in postmenopausal women with early breast cancer receiving adjuvant letrozole.

Magee-Womens Hospital, Pittsburgh, Pennsylvania 15123, USA. brufskyam@upmc.edu

BACKGROUND: The interim (12-month) results of two similarly designed, ongoing studies (the Zometa-Femara Adjuvant Synergy Trials [Z-FAST and ZO-FAST]) suggest that zoledronic acid (4 mg intravenously every 6 months) when initiated with adjuvant letrozole increases bone mineral density (BMD) of the lumbar spine (LS) in postmenopausal women with early-stage breast cancer compared with patients who receive zoledronic acid only when bone loss became clinically significant or a fragility fracture occurred. METHODS: An integrated analysis was performed to maximize the value of the large pool of data from the two studies in answering clinically relevant questions. The primary objective was to compare the change in LS BMD at month 12. Secondary objectives included comparing (a) the change in total hip (TH) BMD, (b) changes in bone turnover marker concentrations, (c) time to disease recurrence, and (d) safety at month 12. FINDINGS: The integrated analysis included 1,667 patients. At month 12, LS BMD was 5.2% higher in the upfront group than in the delayed group; TH BMD was 3.5% higher. N-telopeptide and bone-specific alkaline phosphatase concentrations decreased by 21.3% and 12.8% in the upfront group and increased by 21.7% and 24.9% in the delayed group, respectively (p < .0001 for intergroup comparisons). Fewer patients receiving upfront zoledronic acid experienced disease recurrence than patients in the delayed group-seven patients (0.84%) versus 17 patients (1.9%) (p = .0401). Fracture rates were similar. No confirmed osteonecrosis of the jaw was reported. CONCLUSIONS: The results of this analysis strengthen the statistical validity of the preliminary results of the Z-FAST and ZO-FAST studies, showing that upfront zoledronic acid prevents aromatase inhibitor-associated bone loss more effectively than delayed-start zoledronic acid in postmenopausal women with early-stage breast cancer receiving letrozole. Additionally, disease recurrence appears to be lower with upfront zoledronic acid, but further follow-up is needed to confirm these interim results.

PMID: 18515735 [PubMed - in process]

1: Cancer. 2008 May 5;113(1):193-201. [Epub ahead of print] Links

Normalization of bone markers is associated with improved survival in patients with bone metastases from solid tumors and elevated bone resorption receiving zoledronic acid.

Department of Hematology]Oncology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, Pennsylvania.

BACKGROUND.: For patients with bone metastases, high N-telopeptide of type I collagen (NTX) levels correlate with increased risks of skeletal-related events and death. However, the relation between NTX decreases and clinical benefits is unclear. METHODS.: Correlations between NTX normalization during treatment and clinical outcome were retrospectively analyzed in 3 large, phase 3 trials. Urinary NTX levels were measured at baseline and at Month 3 in patients with bone metastases from breast cancer (BC; n = 578), hormone-refractory prostate cancer (HRPC; n = 472), or nonsmall-cell lung cancer and other solid tumors (NSCLC/OST; n = 291) who received zoledronic acid or control (pamidronate for BC; placebo for HRPC and NSCLC/OST) for up to 24 months. NTX levels were characterized as normal (N; <64 nmol/mmol creatinine) or elevated (E; >/=64 nmol/mmol creatinine). RESULTS.: After 3 months of zoledronic acid, most N-group patients maintained normal levels; however, most E-group patients normalized their NTX levels (BC, 81%; HRPC, 70%; NSCLC/OST, 81%). In contrast, NTX levels normalized with pamidronate in 65% of BC, with placebo in 8% of HRPC, and in 17% of NSCLC/OST E-group patients. Normalized NTX correlated with improved overall survival versus persistently elevated NTX (significant for zoledronic acid-treated patients; trend for placebo-treated patients). Moreover, percentage reductions from baseline NTX levels correlated with benefits regardless of whether patients transitioned from E to N. CONCLUSIONS.: Zoledronic acid normalizes or maintains normal NTX levels in most patients with bone metastases. Normalized NTX within 3 months of treatment, versus persistently elevated NTX, was associated with reduced risks of skeletal complications and death. Cancer 2008. (c) 2008 American Cancer Society.

PMID: 18459173 [PubMed - as supplied by publisher]

1: J Clin Oncol. 2005 May 20;23(15):3314-21. Epub 2005 Feb 28. Links

Comment in:

J Clin Oncol. 2005 May 20;23(15):3299-301.

Zoledronic acid significantly reduces skeletal complications compared with placebo in Japanese women with bone metastases from breast cancer: a randomized, placebo-controlled trial.

Department of Surgery, Hyogo Medical Center for Adults, 13-70 Kitaojicho Akashi 673-0021, Japan. norio@tiger.interq.or.jp

PURPOSE: To investigate the efficacy and safety of zoledronic acid for the treatment of bone metastases from breast cancer. PATIENTS AND METHODS: Women with bone metastases (N = 228) were randomly assigned to receive 4 mg zoledronic acid (n = 114) or placebo (n = 114) via 15-minute infusions every 4 weeks for 1 year. The primary efficacy end point was the skeletal-related event (SRE) rate ratio between treatment groups. An SRE was defined as pathologic fracture, spinal cord compression, and radiation or surgery to bone. Secondary end points included percentage of patients with at least one SRE, time-to-first SRE, and Andersen-Gill multiple-event analysis. RESULTS: The SRE rate ratio at 1 year (excluding HCM and adjusted for prior fracture) was 0.61 (permutation test; P = .027), indicating that zoledronic acid reduced the rate of SRE by 39% compared with placebo. The percentage of patients with at least one SRE (excluding HCM) was significantly reduced by 20% by zoledronic acid (29.8% v 49.6% for placebo; P = .003). Zoledronic acid significantly delayed time-to-first SRE (median not reached v 364 days; Cox regression; P = .007) and reduced the risk of SREs by 41% in multiple event analysis (risk ratio = 0.59; P = .019) compared with placebo. Zoledronic acid was well tolerated with a safety profile similar to placebo. No patient treated with zoledronic acid had grade 3 or 4 serum creatinine increase. CONCLUSION: Zoledronic acid significantly reduced skeletal complications compared with placebo across multiple end points in Japanese women with bone metastases from breast cancer.

PMID: 15738536 [PubMed - indexed for MEDLINE]

1: Cancer. 2008 May 5;113(1):193-201. [Epub ahead of print] Links

Normalization of bone markers is associated with improved survival in patients with bone metastases from solid tumors and elevated bone resorption receiving zoledronic acid.

Department of Hematology]Oncology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, Pennsylvania.

BACKGROUND.: For patients with bone metastases, high N-telopeptide of type I collagen (NTX) levels correlate with increased risks of skeletal-related events and death. However, the relation between NTX decreases and clinical benefits is unclear. METHODS.: Correlations between NTX normalization during treatment and clinical outcome were retrospectively analyzed in 3 large, phase 3 trials. Urinary NTX levels were measured at baseline and at Month 3 in patients with bone metastases from breast cancer (BC; n = 578), hormone-refractory prostate cancer (HRPC; n = 472), or nonsmall-cell lung cancer and other solid tumors (NSCLC/OST; n = 291) who received zoledronic acid or control (pamidronate for BC; placebo for HRPC and NSCLC/OST) for up to 24 months. NTX levels were characterized as normal (N; <64 nmol/mmol creatinine) or elevated (E; >/=64 nmol/mmol creatinine). RESULTS.: After 3 months of zoledronic acid, most N-group patients maintained normal levels; however, most E-group patients normalized their NTX levels (BC, 81%; HRPC, 70%; NSCLC/OST, 81%). In contrast, NTX levels normalized with pamidronate in 65% of BC, with placebo in 8% of HRPC, and in 17% of NSCLC/OST E-group patients. Normalized NTX correlated with improved overall survival versus persistently elevated NTX (significant for zoledronic acid-treated patients; trend for placebo-treated patients). Moreover, percentage reductions from baseline NTX levels correlated with benefits regardless of whether patients transitioned from E to N. CONCLUSIONS.: Zoledronic acid normalizes or maintains normal NTX levels in most patients with bone metastases. Normalized NTX within 3 months of treatment, versus persistently elevated NTX, was associated with reduced risks of skeletal complications and death. Cancer 2008. (c) 2008 American Cancer Society.

PMID: 18459173 [PubMed - as supplied by publisher]