A randomized, double-blind, phase II, exploratory trial evaluating the palliative benefit of either continuing pamidronate or switching to zoledronic acid in patients with high-risk bone metastases from breast cancer.

Journal Article (Journal Article)

Previous studies suggest switching from pamidronate to a more potent bone-targeted agent is associated with biomarker and palliative response in breast cancer patients with bone metastases. Until now, this has not been addressed in a double-blind, randomized trial. Breast cancer patients with high-risk bone metastases, despite >3 months of pamidronate, were randomized to either continue pamidronate or switch to zoledronic acid every 4 weeks for 12 weeks. Primary outcome was the proportion of patients achieving a fall in serum C-telopeptide (sCTx) at 12 weeks. Secondary outcomes included difference in mean sCTx, pain scores, quality of life, toxicity, and skeletal-related events (SREs). Seventy-three patients entered the study; median age 61 years (range 37-87). Proportion of patients achieving a fall in sCTx over the 12-week evaluation period was 26/32 (81 %) with zoledronic acid and 18/29 (62 %) with pamidronate (p = 0.095). Mean decrease in sCTx (mean difference between groups = 50 ng/L, 95 % CI 18-84; p = 0.003) was significantly greater in patients who received zoledronic acid. Quality of life, pain scores, toxicity, and frequency of new SREs were comparable between the two arms. While a switch from pamidronate to zoledronic acid resulted in reduction in mean sCTx, there were no significant differences between the arms for proportion of patients achieving a reduction in sCTx, quality of life, pain scores, toxicity or SREs. Given the lack of palliative improvement, the current data do not support a switching strategy.

Full Text

Duke Authors

Cited Authors

  • Jacobs, C; Kuchuk, I; Bouganim, N; Smith, S; Mazzarello, S; Vandermeer, L; Dranitsaris, G; Dent, S; Gertler, S; Verma, S; Song, X; Simos, S; Cella, D; Clemons, M

Published Date

  • January 2016

Published In

Volume / Issue

  • 155 / 1

Start / End Page

  • 77 - 84

PubMed ID

  • 26643085

Electronic International Standard Serial Number (EISSN)

  • 1573-7217

Digital Object Identifier (DOI)

  • 10.1007/s10549-015-3646-2


  • eng

Conference Location

  • Netherlands