Zometa very month versus every 12 weeks – pro
A recent report of a study that used Zoledronic acid administered every 12 weeks was noninferior to an every 4-week regimen in the phase III CALGB 70604 trial of patients with breast cancer, prostate cancer, or multiple myeloma with bone metastases. This noninferiority trial that included 1,822 patients who were randomly assigned to receive zoledronic acid every 12 weeks or every 4 weeks for 2 years. The primary endpoint was incidence of any skeletal-related event (SRE); 1,766 patients were included in the primary endpoint cohort and 795 completed the 2 years of treatment.
There was no significant difference between the two arms for the primary endpoint, with 29% of patients in both the 4-week arm and the 12-week arm experiencing at least one SRE (p = 0.79). When examining patients according to disease type, there was also no significant difference between the proportion of patients with at least one SRE according to treatment arm.
No significant differences were found between the two arms for time to first SRE (p = 0.60), skeletal morbidity rate (p = 0.75), pain scores (p = 0.75), or Eastern Cooperative Oncology Group performance status (p = 0.64).
Renal dysfunction and osteonecrosis of the jaw were uncommon toxicities and did not significantly differ between the two treatment arms.
Unfortuntly, guidelines do not ercommend q 3 month Zometa, albeit the increased risk of bone side effects on the monthly schedule, full publication fo results is pending, and supporting studies are awaited..
Breast Cancer Disease Site Group. Warr D, Johnston M. Use of bisphosphonates in women with breast cancer [full report]. Toronto (ON): Cancer Care Ontario (CCO); 2004 Apr [online update]. 34 p. (Practice guideline report; no. 1-11). [68 references]
NCCN.ORG, Breast Cancer, 2016
Zolendronic Acid, Prescribing Information2016
Andrew Louis Himelstein et al,CALGB 70604 (Alliance): A randomized phase III study of standard dosing vs. longer interval dosing of zoledronic acid in metastatic cancer.J Clin Oncol 33, 2015 (suppl; abstr 9501)