Efficacy and safety of bone management agents administered at 12 weeks vs. 4 weeks in patients with bone metastases: A systematic review.

Background: Bone modifying agents (BMAs) have been used to prevent skeletal-related events (SRE) in cancer patients with bone metastases. In this meta-analysis, efficacy and adverse events (AEs) were studied based on a de-escalation strategy in which the BMA dosing interval was prolonged from 4 to 12 weeks.

Methods: PubMed, Cochrane, ICHUSHI, and CINAHL were searched for articles on BMA dosing intervals from outcomes measured were the incidence of SRE and related various AEs. A quantitative meta-analysis was performed using a random-effects model to calculate relative risk ratios (RRs) and 95% confidence intervals (CIs).

Result: The meta-analysis included three randomized controlled studies (RCTs) of Zoledronic acid hydrate (ZA) (n = 2663) and six RCTs (n = 141) on BMA other than ZA. There was no difference in the incidence of SREs when comparing the dosing frequency of 12 versus 4 weeks for BMA (RR = 1.21, 95% CI [0.82-1.78], p = 0.33). Further, AEs related to treatment discontinuation were significantly less frequent with ZA given every 12 weeks than when given every 4 weeks (RR = 0.51 [0.30-0.89], p = 0.02). In particular, renal dysfunction leading to grade ≥3 or discontinuation of treatment with ZA occurred significantly less frequently with every 12-week dosing (RR = 0.33 [0.12-0.91], p = 0.33).

Conclusion: This meta-analysis showed no influence of BMA de-escalation on the incidence of SRE; nevertheless, AEs appeared to reduce with the de-escalated usage of ZA.