Effects of intravenous zoledronic acid and oral ibandronate on early changes in markers of bone turnover in patients with bone metastases from non-small cell lung cancer

Background The aim of this study was to assess the early effects of zoledronic acid (ZOL) and oral ibandronate (IBA) on the bone resorption marker s-CTX (serum C-telopeptide of collagen type I) and the bone formation marker B-ALP (bone-alkaline phosphatase) in patients with bone metastases from non-small cell lung cancer (NSCLC). Methods Fifty-five patients with at least one site of bone metastasis secondary to NSCLC were randomly assigned to receive intravenous ZOL 4 mg every 4 weeks, or oral IBA 50 mg/day. Results At 1 month of treatment, s-CTX was reduced by 54.8% (95% CI 40.4–59.8%) in the ZOL group (26 evaluable patients) compared with 38.2% (95% CI 29.8–48.7%) in the oral IBA group (27 evaluable patients) ( p = 0.03). At 3 months, s-CTX was reduced by 72.6% (95% CI 58.6–71.3%) in the ZOL group, compared with 66.4% (95% CI 54.3–79.5%) in the oral IBA group ( p = 0.22). Both bisphosphonates similarly decreased the bone marker B-ALP at 1 month (ZOL 24.7%, 95% CI 3.6–39.5%, and IBA 24.2%, 95% CI 2.8–43.4%) and 3 months (ZOL 28.6%, 95% CI +2.8–43.3%, and IBA 24.2%, 95% CI 3.2–47.4%). Both bisphosphonates were well tolerated. Conclusion Considering the changes in bone markers, ZOL and oral IBA show comparable efficacy in patients with NSCLC and bone metastases.