Abstract
BACKGROUND
The objective of this study was to assess the efficacy and safety of zoledronic acid in patients with bone metastases secondary to renal cell carcinoma (RCC).
METHODS
A retrospective subset analysis of patients with RCC enrolled in a multicenter, randomized, placeboโcontrolled study of zoledronic acid was performed. Patients were randomized to receive zoledronic acid (4 or 8 mg as a 15โminute infusion) or placebo with concomitant antineoplastic therapy every 3 weeks for 9 months. The primary efficacy analysis was the proportion of patients with one or more skeletalโrelated events (SREs), which were defined as pathologic fracture, spinal cord compression, radiation therapy, or surgery to bone. Secondary analyses included time to first SRE, skeletal morbidity rate (events per year), disease progression, and multiple event analysis.
RESULTS
In this subset of 74 patients with RCC, zoledronic acid (4 mg) was found to significantly reduce the proportion of patients with an SRE (37% vs. 74% for placebo; P = 0.015). Similarly, zoledronic acid significantly reduced the mean skeletal morbidity rate (2.68 vs. 3.38 for placebo; P = 0.014) and extended the time to the first event (median not reached vs. 72 days for placebo; P = 0.006). A multiple event analysis demonstrated that the risk of developing an SRE was reduced by 61% compared with placebo (hazard ratio of 0.394; P = 0.008). The median time to progression of bone lesions was significantly longer for patients who were treated with zoledronic acid (P = 0.014 vs. placebo). Zoledronic acid appeared to be well tolerated; the most common adverse events in all treatment groups included bone pain, nausea, anemia, and emesis.
CONCLUSIONS
Zoledronic acid (4 mg as a 15โminute infusion) demonstrated significant clinical benefit in patients with bone metastases from RCC, suggesting that further investigation of zoledronic acid in this patient population is warranted. Cancer 2003;98:962โ9. ยฉ 2003 American Cancer Society.
DOI 10.1002/cncr.11571